refactor: Reimplement OpenDC model using 2.x API

34 files changed, 2380 insertions, 0 deletions

diff --git a/opendc/opendc-core/build.gradle.kts b/opendc/opendc-core/build.gradle.kts
new file mode 100644
index 00000000..0ac1f1ea
--- /dev/null
+++ b/opendc/opendc-core/build.gradle.kts
@@ -0,0 +1,39 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+description = "Base model for datacenter simulation"
+
+/* Build configuration */
+plugins {
+    `kotlin-library-convention`
+}
+
+dependencies {
+    implementation(kotlin("stdlib"))
+    api(project(":odcsim:odcsim-api"))
+
+    testImplementation("org.junit.jupiter:junit-jupiter-api:${Library.JUNIT_JUPITER}")
+    testRuntimeOnly("org.junit.jupiter:junit-jupiter-engine:${Library.JUNIT_JUPITER}")
+    testImplementation("org.junit.platform:junit-platform-launcher:${Library.JUNIT_PLATFORM}")
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Broker.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Broker.kt
new file mode 100644
index 00000000..a3d6b0a7
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Broker.kt
@@ -0,0 +1,41 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core
+
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.SendRef
+
+/**
+ * A broker acting on the various cloud platforms on behalf of the user.
+ */
+interface Broker {
+    /**
+     * Build the runtime behavior of the [Broker].
+     *
+     * @param platforms A list of available cloud platforms.
+     * @return The runtime behavior of the broker.
+     */
+    suspend operator fun invoke(ctx: ProcessContext, platforms: List<SendRef<PlatformMessage>>)
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Cluster.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Cluster.kt
new file mode 100644
index 00000000..da9aed00
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Cluster.kt
@@ -0,0 +1,55 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.SendRef
+import com.atlarge.opendc.core.resources.compute.MachineMessage
+import com.atlarge.opendc.core.resources.compute.host.Host
+import com.atlarge.opendc.core.resources.compute.supervision.MachineSupervisionEvent
+import java.util.UUID
+
+/**
+ * A logical grouping of heterogeneous hosts and primary storage within a zone.
+ *
+ * @property uid The unique identifier of the cluster.
+ * @property name The name of this cluster.
+ * @property hosts The machines in this cluster.
+ */
+data class Cluster(override val uid: UUID, override val name: String, val hosts: List<Host>) : Identity {
+    /**
+     * Build the runtime [Behavior] of this cluster of hosts.
+     *
+     * @param manager The manager of the cluster.
+     */
+    suspend operator fun invoke(ctx: ProcessContext, manager: SendRef<MachineSupervisionEvent>) {
+        // Launch all hosts in the cluster
+        for (host in hosts) {
+            val channel = ctx.open<MachineMessage>()
+            ctx.spawn({ host(it, manager, channel) }, name = host.name)
+        }
+    }
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Environment.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Environment.kt
new file mode 100644
index 00000000..5bdff0b6
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Environment.kt
@@ -0,0 +1,36 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core
+
+/**
+ * A description of a large-scale computing environment. This description includes including key size and topology
+ * information of the environment, types of resources, but also various operational and management rules such as
+ * scheduled maintenance, allocation and other constraints.
+ *
+ * @property name The name of the environment.
+ * @property description A small textual description about the environment that is being modeled
+ * @property platforms The cloud platforms (such as AWS or GCE) in this environment.
+ */
+data class Environment(val name: String, val description: String?, val platforms: List<Platform>)
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Identity.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Identity.kt
new file mode 100644
index 00000000..c87e934f
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Identity.kt
@@ -0,0 +1,42 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core
+
+import java.util.UUID
+
+/**
+ * An object that has a unique identity.
+ */
+interface Identity {
+    /**
+     * A unique, opaque, system-generated value, representing the object.
+     */
+    val uid: UUID
+
+    /**
+     * A non-empty, human-readable string representing the object.
+     */
+    val name: String
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Model.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Model.kt
new file mode 100644
index 00000000..3d16c4b2
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Model.kt
@@ -0,0 +1,51 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core
+
+import com.atlarge.odcsim.ProcessContext
+
+/**
+ * A simulation model for large-scale simulation of datacenter infrastructure, built with the *odcsim* API.
+ *
+ * @property environment The environment in which brokers operate.
+ * @property brokers The brokers acting on the cloud platforms.
+ */
+data class Model(val environment: Environment, val brokers: List<Broker>) {
+    /**
+     * Build the runtime behavior of the universe.
+     */
+    suspend operator fun invoke(ctx: ProcessContext) {
+        // Setup the environment
+        val platforms = environment.platforms.map { platform ->
+            val channel = ctx.open<PlatformMessage>()
+            ctx.spawn({ platform(it, channel.receive) }, name = platform.name)
+            channel.send
+        }
+
+        for (broker in brokers) {
+            ctx.spawn { broker(it, platforms) }
+        }
+    }
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Platform.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Platform.kt
new file mode 100644
index 00000000..fab67962
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Platform.kt
@@ -0,0 +1,103 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.ReceiveRef
+import com.atlarge.odcsim.SendRef
+import com.atlarge.odcsim.ask
+import com.atlarge.odcsim.sendOnce
+import java.util.UUID
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.isActive
+
+/**
+ * A representation of a cloud platform such as Amazon Web Services (AWS), Microsoft Azure or Google Cloud.
+ *
+ * @property uid The unique identifier of this datacenter.
+ * @property name the name of the platform.
+ * @property zones The availability zones available on this platform.
+ */
+data class Platform(override val uid: UUID, override val name: String, val zones: List<Zone>) : Identity {
+    /**
+     * Build the runtime [Behavior] of this cloud platform.
+     */
+    suspend operator fun invoke(ctx: ProcessContext, main: ReceiveRef<PlatformMessage>) {
+        println("Starting cloud platform $name [$uid] with ${zones.size} zones")
+
+        // Launch all zones of the cloud platform
+        val zoneInstances = zones.associateWith { zone ->
+            val channel = ctx.open<ZoneMessage>()
+            ctx.spawn({ zone(it, channel) }, name = zone.name)
+            channel.send
+        }
+
+        val inlet = ctx.listen(main)
+        coroutineScope {
+            while (isActive) {
+                when (val msg = inlet.receive()) {
+                    is PlatformMessage.ListZones -> {
+                        msg.replyTo.sendOnce(PlatformResponse.Zones(this@Platform, zoneInstances.mapKeys { it.key.name }))
+                    }
+                }
+            }
+        }
+        inlet.close()
+    }
+}
+
+/**
+ * A message protocol for communicating with a cloud platform.
+ */
+sealed class PlatformMessage {
+    /**
+     * Request the available zones on this platform.
+     *
+     * @property replyTo The actor address to send the response to.
+     */
+    data class ListZones(val replyTo: SendRef<PlatformResponse.Zones>) : PlatformMessage()
+}
+
+/**
+ * A message protocol used by platform actors to respond to [PlatformMessage]s.
+ */
+sealed class PlatformResponse {
+    /**
+     * The zones available on this cloud platform.
+     *
+     * @property platform The reference to the cloud platform these are the zones of.
+     * @property zones The zones in this cloud platform.
+     */
+    data class Zones(val platform: Platform, val zones: Map<String, SendRef<ZoneMessage>>) : PlatformResponse()
+}
+
+/**
+ * Retrieve the available zones of a platform.
+ */
+suspend fun SendRef<PlatformMessage>.zones(): Map<String, SendRef<ZoneMessage>> {
+    val zones: PlatformResponse.Zones = ask { PlatformMessage.ListZones(it) }
+    return zones.zones
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/User.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/User.kt
new file mode 100644
index 00000000..6105ae9e
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/User.kt
@@ -0,0 +1,35 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core
+
+/**
+ * A user of the cloud network.
+ */
+interface User : Identity {
+    /**
+     * The name of the user.
+     */
+    override val name: String
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Zone.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Zone.kt
new file mode 100644
index 00000000..07361423
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/Zone.kt
@@ -0,0 +1,194 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.Channel
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.SendRef
+import com.atlarge.odcsim.ask
+import com.atlarge.odcsim.sendOnce
+import com.atlarge.opendc.core.services.Service
+import com.atlarge.opendc.core.services.ServiceProvider
+import java.util.ArrayDeque
+import java.util.UUID
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.isActive
+
+/**
+ * An isolated location within a datacenter region from which public cloud services operate, roughly equivalent to a
+ * single datacenter. Zones contain one or more clusters and secondary storage.
+ *
+ * This class models *only* the static information of a zone, with dynamic information being contained within the zone's
+ * actor. During runtime, it's actor acts as a registry for all the cloud services provided by the zone.
+ *
+ * @property uid The unique identifier of this availability zone
+ * @property name The name of the zone within its platform.
+ * @property services The initial set of services provided by the zone.
+ * @property clusters The clusters of machines in this zone.
+ */
+data class Zone(
+    override val uid: UUID,
+    override val name: String,
+    val services: Set<ServiceProvider>,
+    val clusters: List<Cluster>
+) : Identity {
+    /**
+     * Build the runtime [Behavior] of this datacenter.
+     */
+    suspend operator fun invoke(ctx: ProcessContext, main: Channel<ZoneMessage>) {
+        println("Starting zone $name [$uid]")
+
+        // Launch all services of the zone
+        val instances: MutableMap<Service<*>, SendRef<*>> = mutableMapOf()
+        validateDependencies(services)
+
+        for (provider in services) {
+            val channel = ctx.open<Any>()
+            println("Spawning service ${provider.name}")
+            ctx.spawn({ provider(it, this, main.send, channel) }, name = "${provider.name}-${provider.uid}")
+            provider.provides.forEach { instances[it] = channel.send }
+        }
+
+        val inlet = ctx.listen(main.receive)
+
+        coroutineScope {
+            while (isActive) {
+                when (val msg = inlet.receive()) {
+                    is ZoneMessage.Find -> {
+                        msg.replyTo.sendOnce(ZoneResponse.Listing(this@Zone, msg.key, instances[msg.key]))
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * Validate the service for unsatisfiable dependencies.
+     */
+    private fun validateDependencies(providers: Set<ServiceProvider>) {
+        val providersByKey = HashMap<Service<*>, ServiceProvider>()
+        for (provider in providers) {
+            if (provider.provides.isEmpty()) {
+                throw IllegalArgumentException(("Service provider $provider does not provide any service."))
+            }
+            for (key in provider.provides) {
+                if (key in providersByKey) {
+                    throw IllegalArgumentException("Multiple providers for service $key")
+                }
+                providersByKey[key] = provider
+            }
+        }
+
+        val visited = HashSet<ServiceProvider>()
+        val queue = ArrayDeque(providers)
+        while (queue.isNotEmpty()) {
+            val service = queue.poll()
+            visited.add(service)
+
+            for (dependencyKey in service.dependencies) {
+                val dependency = providersByKey[dependencyKey]
+                    ?: throw IllegalArgumentException("Dependency $dependencyKey not satisfied for service $service")
+                if (dependency !in visited) {
+                    queue.add(dependency)
+                }
+            }
+        }
+    }
+
+    override fun equals(other: Any?): Boolean = other is Zone && uid == other.uid
+    override fun hashCode(): Int = uid.hashCode()
+}
+
+/**
+ * A message protocol for communicating with the service registry
+ */
+sealed class ZoneMessage {
+    /**
+     * Lookup the specified service in this availability zone.
+     *
+     * @property key The key of the service to lookup.
+     * @property replyTo The address to reply to.
+     */
+    data class Find(
+        val key: Service<*>,
+        val replyTo: SendRef<ZoneResponse.Listing>
+    ) : ZoneMessage()
+}
+
+/**
+ * A message protocol used by service registry actors to respond to [ZoneMessage]s.
+ */
+sealed class ZoneResponse {
+    /**
+     * The response sent when looking up services in a zone.
+     *
+     * @property zone The zone from which the response originates.
+     * @property key The key of the service that was looked up.
+     * @property ref The reference to the service or `null` if it is not present in the zone.
+     */
+    data class Listing(
+        val zone: Zone,
+        val key: Service<*>,
+        private val ref: SendRef<*>?
+    ) : ZoneResponse() {
+        /**
+         * A flag to indicate whether the service is present.
+         */
+        val isPresent: Boolean
+            get() = ref != null
+
+        /**
+         * Determine whether this listing is for the specified key.
+         *
+         * @param key The key to check for.
+         * @return `true` if the listing is for this key, `false` otherwise.
+         */
+        fun isForKey(key: Service<*>): Boolean = key == this.key
+
+        /**
+         * Extract the result from the service lookup.
+         *
+         * @param key The key of the lookup.
+         * @return The reference to the service or `null` if it is not present in the zone.
+         */
+        operator fun <T : Any> invoke(key: Service<T>): SendRef<T>? {
+            require(this.key == key) { "Invalid key" }
+            @Suppress("UNCHECKED_CAST")
+            return ref as? SendRef<T>
+        }
+    }
+}
+
+/**
+ * Find the reference to the specified [ServiceProvider].
+ *
+ * @param key The key of the service to find.
+ * @throws IllegalArgumentException if the service is not found.
+ */
+suspend fun <T : Any> SendRef<ZoneMessage>.find(key: Service<T>): SendRef<T> {
+    val listing: ZoneResponse.Listing = ask { ZoneMessage.Find(key, it) }
+    return listing(key) ?: throw IllegalArgumentException("Unknown key $key")
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/Machine.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/Machine.kt
new file mode 100644
index 00000000..f25fa3cc
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/Machine.kt
@@ -0,0 +1,107 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.Channel
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.SendRef
+import com.atlarge.opendc.core.Identity
+import com.atlarge.opendc.core.resources.compute.supervision.MachineSupervisionEvent
+import com.atlarge.opendc.core.workload.application.Application
+import com.atlarge.opendc.core.workload.application.Pid
+
+/**
+ * A generic representation of a compute node (either physical or virtual) that is able to run [Application]s.
+ */
+interface Machine : Identity {
+    /**
+     * The details of the machine in key/value pairs.
+     */
+    val details: Map<String, Any>
+
+    /**
+     * Build the runtime [Behavior] of this compute resource, accepting messages of [MachineMessage].
+     *
+     * @param supervisor The supervisor of the machine.
+     */
+    suspend operator fun invoke(ctx: ProcessContext, supervisor: SendRef<MachineSupervisionEvent>, main: Channel<MachineMessage>)
+}
+
+/**
+ * A reference to a machine instance that accepts messages of type [MachineMessage].
+ */
+typealias MachineRef = SendRef<MachineMessage>
+
+/**
+ * A message protocol for communicating with machine instances.
+ */
+sealed class MachineMessage {
+    /**
+     * Launch the specified [Application] on the machine instance.
+     *
+     * @property application The application to submit.
+     * @property key The key to identify this submission.
+     * @property broker The broker of the process to spawn.
+     */
+    data class Submit(
+        val application: Application,
+        val key: Any,
+        val broker: SendRef<MachineEvent>
+    ) : MachineMessage()
+}
+
+/**
+ * A message protocol used by machine instances to respond to [MachineMessage]s.
+ */
+sealed class MachineEvent {
+    /**
+     * Indicate that an [Application] was spawned on a machine instance.
+     *
+     * @property instance The machine instance to which the application was submitted.
+     * @property application The application that has been submitted.
+     * @property key The key used to identify the submission.
+     * @property pid The spawned application instance.
+     */
+    data class Submitted(
+        val instance: MachineRef,
+        val application: Application,
+        val key: Any,
+        val pid: Pid
+    ) : MachineEvent()
+
+    /**
+     * Indicate that an [Application] has terminated on the specified machine.
+     *
+     * @property instance The machine instance to which the application was submitted.
+     * @property pid The reference to the application instance that has terminated.
+     * @property status The exit code of the task, where zero means successful.
+     */
+    data class Terminated(
+        val instance: MachineRef,
+        val pid: Pid,
+        val status: Int = 0
+    ) : MachineEvent()
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/MachineStatus.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/MachineStatus.kt
new file mode 100644
index 00000000..af039bcc
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/MachineStatus.kt
@@ -0,0 +1,33 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute
+
+/**
+ * The status of a machine.
+ */
+enum class MachineStatus {
+    HALT,
+    RUNNING
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/ProcessingElement.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/ProcessingElement.kt
new file mode 100644
index 00000000..23a5b444
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/ProcessingElement.kt
@@ -0,0 +1,33 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute
+
+/**
+ * A logical core in a CPU.
+ *
+ * @property id The identifier of the core within the CPU.
+ * @property unit The [ProcessingUnit] the core is part of.
+ */
+data class ProcessingElement(val id: Int, val unit: ProcessingUnit)
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/ProcessingUnit.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/ProcessingUnit.kt
new file mode 100644
index 00000000..76985f64
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/ProcessingUnit.kt
@@ -0,0 +1,44 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute
+
+/**
+ * A processing unit of a compute resource, either virtual or physical.
+ *
+ * @property vendor The vendor string of the cpu.
+ * @property family The cpu family number.
+ * @property model The model number of the cpu.
+ * @property modelName The name of the cpu model.
+ * @property clockRate The clock speed of the cpu in MHz.
+ * @property cores The number of logical cores in the cpu.
+ */
+data class ProcessingUnit(
+    val vendor: String,
+    val family: Int,
+    val model: Int,
+    val modelName: String,
+    val clockRate: Double,
+    val cores: Int
+)
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/host/Host.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/host/Host.kt
new file mode 100644
index 00000000..21217468
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/host/Host.kt
@@ -0,0 +1,83 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute.host
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.Channel
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.SendRef
+import com.atlarge.odcsim.sendOnce
+import com.atlarge.opendc.core.resources.compute.Machine
+import com.atlarge.opendc.core.resources.compute.MachineMessage
+import com.atlarge.opendc.core.resources.compute.ProcessingElement
+import com.atlarge.opendc.core.resources.compute.scheduling.MachineScheduler
+import com.atlarge.opendc.core.resources.compute.supervision.MachineSupervisionEvent
+import java.util.UUID
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.isActive
+
+/**
+ * A physical compute node in a datacenter that is able to run [Application]s.
+ *
+ * @property uid The unique identifier of this machine.
+ * @property name The name of the machine.
+ * @property scheduler The process scheduler of this machine.
+ * @property cores The list of processing elements in the machine.
+ * @property details The details of this host.
+ */
+data class Host(
+    override val uid: UUID,
+    override val name: String,
+    val scheduler: MachineScheduler,
+    val cores: List<ProcessingElement>,
+    override val details: Map<String, Any> = emptyMap()
+) : Machine {
+    /**
+     * Build the [Behavior] for a physical machine.
+     */
+    override suspend fun invoke(ctx: ProcessContext, supervisor: SendRef<MachineSupervisionEvent>, main: Channel<MachineMessage>) {
+        coroutineScope {
+            supervisor.sendOnce(MachineSupervisionEvent.Announce(this@Host, main.send))
+            supervisor.sendOnce(MachineSupervisionEvent.Up(main.send))
+
+            val sched = scheduler(ctx, this, this@Host, main.send)
+            sched.updateResources(cores)
+
+            val inlet = ctx.listen(main.receive)
+            while (isActive) {
+                when (val msg = inlet.receive()) {
+                    is MachineMessage.Submit -> {
+                        sched.submit(msg.application, msg.key, msg.broker)
+                    }
+                }
+            }
+            inlet.close()
+        }
+    }
+
+    override fun equals(other: Any?): Boolean = other is Machine && uid == other.uid
+
+    override fun hashCode(): Int = uid.hashCode()
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/MachineScheduler.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/MachineScheduler.kt
new file mode 100644
index 00000000..400c6a0f
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/MachineScheduler.kt
@@ -0,0 +1,42 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute.scheduling
+
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.opendc.core.resources.compute.Machine
+import com.atlarge.opendc.core.resources.compute.MachineRef
+import kotlinx.coroutines.CoroutineScope
+
+/**
+ * A factory interface for constructing a [MachineSchedulerLogic].
+ */
+interface MachineScheduler {
+    /**
+     * Construct a [MachineSchedulerLogic] in the given [ProcessContext].
+     *
+     * @param machine The machine to create the scheduler for.
+     */
+    operator fun invoke(ctx: ProcessContext, coroutineScope: CoroutineScope, machine: Machine, machineRef: MachineRef): MachineSchedulerLogic
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/MachineSchedulerLogic.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/MachineSchedulerLogic.kt
new file mode 100644
index 00000000..9bc20eb8
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/MachineSchedulerLogic.kt
@@ -0,0 +1,64 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute.scheduling
+
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.SendRef
+import com.atlarge.opendc.core.resources.compute.Machine
+import com.atlarge.opendc.core.resources.compute.MachineEvent
+import com.atlarge.opendc.core.resources.compute.MachineRef
+import com.atlarge.opendc.core.resources.compute.ProcessingElement
+import com.atlarge.opendc.core.workload.application.Application
+import com.atlarge.opendc.core.workload.application.ProcessSupervisor
+import kotlinx.coroutines.CoroutineScope
+
+/**
+ * A scheduler that distributes processes over processing elements in a machine.
+ *
+ * @property ctx The context in which the scheduler runs.
+ * @property machine The machine to create the scheduler for.
+ */
+abstract class MachineSchedulerLogic(
+    protected val ctx: ProcessContext,
+    protected val coroutineScope: CoroutineScope,
+    protected val machine: Machine,
+    protected val machineRef: MachineRef
+) : ProcessSupervisor {
+    /**
+     * Update the available resources in the machine.
+     *
+     * @param cores The available processing cores for the scheduler.
+     */
+    abstract suspend fun updateResources(cores: List<ProcessingElement>)
+
+    /**
+     * Submit the specified application for scheduling.
+     *
+     * @param application The application to submit.
+     * @param key The key to identify the application instance.
+     * @param handler The broker of this application.
+     */
+    abstract suspend fun submit(application: Application, key: Any, handler: SendRef<MachineEvent>)
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/ProcessObserver.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/ProcessObserver.kt
new file mode 100644
index 00000000..2cfeec06
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/ProcessObserver.kt
@@ -0,0 +1,77 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute.scheduling
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.ReceiveRef
+import com.atlarge.opendc.core.resources.compute.MachineEvent
+import com.atlarge.opendc.core.resources.compute.MachineRef
+import com.atlarge.opendc.core.workload.application.Application
+import com.atlarge.opendc.core.workload.application.Pid
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.isActive
+
+/**
+ * An interface for observing processes.
+ */
+interface ProcessObserver {
+    /**
+     * This method is invoked when the setup of an application completed successfully.
+     *
+     * @param pid The process id of the process that has been initialized.
+     */
+    fun onSubmission(instance: MachineRef, application: Application, key: Any, pid: Pid)
+
+    /**
+     * This method is invoked when a process exits.
+     *
+     * @property pid A reference to the application instance.
+     * @property status The exit code of the task, where zero means successful.
+     */
+    fun onTermination(instance: MachineRef, pid: Pid, status: Int)
+
+    companion object {
+        /**
+         * Create the [Behavior] for a [ProcessObserver].
+         *
+         * @param observer The observer to create the behavior for.
+         */
+        suspend operator fun invoke(ctx: ProcessContext, observer: ProcessObserver, main: ReceiveRef<Any>) {
+            val inlet = ctx.listen(main)
+
+            coroutineScope {
+                while (isActive) {
+                    when (val msg = inlet.receive()) {
+                        is MachineEvent.Submitted -> observer.onSubmission(msg.instance, msg.application, msg.key, msg.pid)
+                        is MachineEvent.Terminated -> observer.onTermination(msg.instance, msg.pid, msg.status)
+                    }
+                }
+            }
+
+            inlet.close()
+        }
+    }
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/ProcessState.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/ProcessState.kt
new file mode 100644
index 00000000..e9e9a53e
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/ProcessState.kt
@@ -0,0 +1,50 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute.scheduling
+
+/**
+ * An enumeration of the distinct states of an application instance (process).
+ */
+enum class ProcessState {
+    /**
+     * Default state of a process, where the task is waiting to be assigned and installed on a machine.
+     */
+    CREATED,
+
+    /**
+     * State to indicate that the process is waiting to be ran.
+     */
+    READY,
+
+    /**
+     * State to indicate that the process is currently running.
+     */
+    RUNNING,
+
+    /**
+     * State to indicate that the process has been terminated, either successfully or due to failure.
+     */
+    TERMINATED,
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/ProcessView.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/ProcessView.kt
new file mode 100644
index 00000000..daf71af4
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/ProcessView.kt
@@ -0,0 +1,53 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute.scheduling
+
+import com.atlarge.odcsim.SendRef
+import com.atlarge.opendc.core.resources.compute.MachineEvent
+import com.atlarge.opendc.core.workload.application.Application
+import com.atlarge.opendc.core.workload.application.Pid
+import com.atlarge.opendc.core.workload.application.ProcessMessage
+
+/**
+ * A process represents a application instance running on a particular machine from the machine scheduler's point of
+ * view.
+ *
+ * @property application The application this is an instance of.
+ * @property broker The broker of the process, which is informed about its progress.
+ * @property pid The reference to the application instance.
+ * @property state The state of the process.
+ */
+data class ProcessView(
+    val application: Application,
+    val broker: SendRef<MachineEvent>,
+    val pid: Pid,
+    var state: ProcessState = ProcessState.CREATED
+) {
+    /**
+     * The slice of processing elements allocated for the process. Available as soon as the state
+     * becomes [ProcessState.RUNNING]
+     */
+    lateinit var allocation: ProcessMessage.Allocation
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/SpaceSharedMachineScheduler.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/SpaceSharedMachineScheduler.kt
new file mode 100644
index 00000000..6cdc3ea5
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/scheduling/SpaceSharedMachineScheduler.kt
@@ -0,0 +1,189 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute.scheduling
+
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.SendRef
+import com.atlarge.odcsim.sendOnce
+import com.atlarge.opendc.core.resources.compute.Machine
+import com.atlarge.opendc.core.resources.compute.MachineEvent
+import com.atlarge.opendc.core.resources.compute.MachineRef
+import com.atlarge.opendc.core.resources.compute.ProcessingElement
+import com.atlarge.opendc.core.workload.application.Application
+import com.atlarge.opendc.core.workload.application.Pid
+import com.atlarge.opendc.core.workload.application.ProcessEvent
+import com.atlarge.opendc.core.workload.application.ProcessMessage
+import com.atlarge.opendc.core.workload.application.ProcessSupervisor
+import java.util.ArrayDeque
+import java.util.UUID
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
+
+/**
+ * A machine scheduling policy where processes are space-shared on the machine.
+ *
+ * Space-sharing for machine scheduling means that all running processes will be allocated a separate set of the
+ * [ProcessingElement]s in a [Machine]. Applications are scheduled on the machine in first-in-first-out (FIFO) order,
+ * thus larger applications may block smaller tasks from proceeding, while space is available (no backfilling).
+ *
+ * @property ctx The context in which the scheduler runs.
+ * @property machine The machine to create the scheduler for.
+ */
+class SpaceSharedMachineScheduler(
+    ctx: ProcessContext,
+    coroutineScope: CoroutineScope,
+    machine: Machine,
+    machineRef: MachineRef
+) : MachineSchedulerLogic(ctx, coroutineScope, machine, machineRef), ProcessSupervisor {
+    private var cores = 0
+    private val available = ArrayDeque<ProcessingElement>()
+    private val queue = ArrayDeque<SendRef<ProcessMessage>>()
+    private val running = LinkedHashSet<SendRef<ProcessMessage>>()
+    private val processes = HashMap<SendRef<ProcessMessage>, ProcessView>()
+    private val jobs = HashMap<SendRef<ProcessMessage>, Job>()
+    private val channel = ctx.open<ProcessEvent>()
+
+    init {
+        coroutineScope.launch {
+            ProcessSupervisor(ctx, this@SpaceSharedMachineScheduler, channel.receive)
+        }
+    }
+
+    override suspend fun updateResources(cores: List<ProcessingElement>) {
+        available.addAll(cores)
+        this.cores = cores.size
+
+        // Add all running tasks in front of the queue
+        running.reversed().forEach { queue.addFirst(it) }
+        running.clear()
+
+        reschedule()
+    }
+
+    override suspend fun submit(application: Application, key: Any, handler: SendRef<MachineEvent>) {
+        val channel = ctx.open<ProcessMessage>()
+        val pid = channel.send
+        // Create application instance on the machine
+        ctx.spawn({ application(it, pid, channel.receive) }, name = application.name + ":" + application.uid + ":" + UUID.randomUUID().toString())
+        processes[pid] = ProcessView(application, handler, pid)
+
+        // Inform the owner that the task has been submitted
+        handler.sendOnce(MachineEvent.Submitted(machineRef, application, key, pid))
+
+        // Setup the task
+        pid.sendOnce(ProcessMessage.Setup(machine, this@SpaceSharedMachineScheduler.channel.send))
+    }
+
+    /**
+     * Reschedule the tasks on this machine.
+     */
+    private fun reschedule() {
+        while (queue.isNotEmpty()) {
+            val pid = queue.peek()
+            val process = processes[pid]!!
+
+            if (process.application.cores >= cores) {
+                // The task will never fit on the machine
+                // TODO Fail task
+                println("Process $process will not fit in machine: dropping.")
+                queue.remove()
+                return
+            } else if (process.application.cores > available.size) {
+                // The task will not fit at the moment
+                // Try again if resources become available
+                // ctx.log.debug("Application queued: not enough processing elements available [requested={}, available={}]",
+                //    process.application.cores, available.size)
+                return
+            }
+            queue.remove()
+
+            // Compute the available resources
+            val resources = List(process.application.cores) {
+                val pe = available.poll()
+                Pair(pe, 1.0)
+            }.toMap()
+            process.state = ProcessState.RUNNING
+            process.allocation = ProcessMessage.Allocation(resources, Long.MAX_VALUE)
+            running += pid
+
+            coroutineScope.launch(Dispatchers.Unconfined) {
+                pid.sendOnce(process.allocation)
+            }
+        }
+    }
+
+    override fun onReady(pid: Pid) {
+        val process = processes[pid]!!
+
+        // Schedule the task if it has been setup
+        queue.add(pid)
+        process.state = ProcessState.READY
+
+        reschedule()
+    }
+
+    override fun onConsume(pid: Pid, utilization: Map<ProcessingElement, Double>, until: Long) {
+        val process = processes[pid]!!
+        val allocation = process.allocation
+
+        if (until > allocation.until) {
+            // Tasks are not allowed to extend allocation provided by the machine
+            // TODO Fail the task
+            println("Task $pid must not extend allocation provided by the machine")
+        } else if (until < allocation.until) {
+            // Shrink allocation
+            process.allocation = allocation.copy(until = until)
+        }
+
+        // Reschedule the process after the allocation expires
+        jobs[pid] = coroutineScope.launch {
+            delay(process.allocation.until - ctx.clock.millis())
+            // We just extend the allocation
+            process.allocation = process.allocation.copy(until = Long.MAX_VALUE)
+            pid.sendOnce(process.allocation)
+        }
+    }
+
+    override fun onExit(pid: Pid, status: Int) {
+        val process = processes.remove(pid)!!
+        running -= pid
+        jobs[pid]?.cancel()
+        process.allocation.resources.keys.forEach { available.add(it) }
+
+        // Inform the owner that the task has terminated
+        coroutineScope.launch {
+            process.broker.sendOnce(MachineEvent.Terminated(machineRef, pid, status))
+        }
+    }
+
+    companion object : MachineScheduler {
+        override fun invoke(ctx: ProcessContext, coroutineScope: CoroutineScope, machine: Machine, machineRef: MachineRef): MachineSchedulerLogic {
+            return SpaceSharedMachineScheduler(ctx, coroutineScope, machine, machineRef)
+        }
+    }
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/supervision/MachineSupervisionEvent.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/supervision/MachineSupervisionEvent.kt
new file mode 100644
index 00000000..8a022112
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/supervision/MachineSupervisionEvent.kt
@@ -0,0 +1,49 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute.supervision
+
+import com.atlarge.opendc.core.resources.compute.Machine
+import com.atlarge.opendc.core.resources.compute.MachineRef
+
+/**
+ * A supervision protocol for [Machine] instances.
+ */
+sealed class MachineSupervisionEvent {
+    /**
+     * Initialization message to introduce to the supervisor a new machine by specifying its static information and
+     * address.
+     *
+     * @property machine The machine that is being announced.
+     * @property ref The address to talk to the host.
+     */
+    data class Announce(val machine: Machine, val ref: MachineRef) : MachineSupervisionEvent()
+
+    /**
+     * Indicate that the specified machine has booted up.
+     *
+     * @property ref The address to talk to the machine.
+     */
+    data class Up(val ref: MachineRef) : MachineSupervisionEvent()
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/supervision/MachineSupervisor.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/supervision/MachineSupervisor.kt
new file mode 100644
index 00000000..37cf9d44
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/resources/compute/supervision/MachineSupervisor.kt
@@ -0,0 +1,76 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.resources.compute.supervision
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.ReceiveRef
+import com.atlarge.opendc.core.resources.compute.Machine
+import com.atlarge.opendc.core.resources.compute.MachineRef
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.isActive
+
+/**
+ * An interface for supervising [Machine] instances.
+ */
+interface MachineSupervisor {
+    /**
+     * This method is invoked when a new machine is introduced to the supervisor by specifying its static information
+     * and address.
+     *
+     * @param machine The machine that is being announced.
+     * @param ref The address to talk to the host.
+     */
+    fun onAnnounce(machine: Machine, ref: MachineRef)
+
+    /**
+     * This method is invoked when a process exits.
+     *
+     * @param ref The address to talk to the machine.
+     */
+    fun onUp(ref: MachineRef)
+
+    companion object {
+        /**
+         * Create the [Behavior] for a [MachineSupervisor].
+         *
+         * @param supervisor The supervisor to create the behavior for.
+         */
+        suspend operator fun invoke(ctx: ProcessContext, supervisor: MachineSupervisor, main: ReceiveRef<MachineSupervisionEvent>) {
+            val inlet = ctx.listen(main)
+
+            coroutineScope {
+                while (isActive) {
+                    when (val msg = inlet.receive()) {
+                        is MachineSupervisionEvent.Announce -> supervisor.onAnnounce(msg.machine, msg.ref)
+                        is MachineSupervisionEvent.Up -> supervisor.onUp(msg.ref)
+                    }
+                }
+            }
+
+            inlet.close()
+        }
+    }
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/Service.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/Service.kt
new file mode 100644
index 00000000..8dcec760
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/Service.kt
@@ -0,0 +1,47 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.services
+
+import com.atlarge.opendc.core.Identity
+import java.util.UUID
+
+/**
+ * An interface for identifying service implementations of the same type (providing the same service).
+ *
+ * @param T The shape of the messages the service responds to.
+ */
+interface Service<T : Any> : Identity
+
+/**
+ * Helper class for constructing a [Service].
+ *
+ * @property uid The unique identifier of the service.
+ * @property name The name of the service.
+ */
+abstract class AbstractService<T : Any>(override val uid: UUID, override val name: String) : Service<T> {
+    override fun equals(other: Any?): Boolean = other is Service<*> && uid == other.uid
+    override fun hashCode(): Int = uid.hashCode()
+    override fun toString(): String = "Service[uid=$uid,name=$name]"
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/ServiceMap.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/ServiceMap.kt
new file mode 100644
index 00000000..14cf4845
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/ServiceMap.kt
@@ -0,0 +1,49 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.services
+
+import com.atlarge.odcsim.SendRef
+
+/**
+ * A map containing services.
+ */
+interface ServiceMap {
+    /**
+     * Determine if this map contains the service with the specified [Service].
+     *
+     * @param key The key of the service to check for.
+     * @return `true` if the service is in the map, `false` otherwise.
+     */
+    operator fun contains(key: Service<*>): Boolean
+
+    /**
+     * Obtain the service with the specified [Service].
+     *
+     * @param key The key of the service to obtain.
+     * @return The references to the service.
+     * @throws IllegalArgumentException if the key does not exists in the map.
+     */
+    operator fun <T : Any> get(key: Service<T>): SendRef<T>
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/ServiceProvider.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/ServiceProvider.kt
new file mode 100644
index 00000000..3592d578
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/ServiceProvider.kt
@@ -0,0 +1,68 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.services
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.Channel
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.SendRef
+import com.atlarge.opendc.core.Identity
+import com.atlarge.opendc.core.Zone
+import com.atlarge.opendc.core.ZoneMessage
+import java.util.UUID
+
+/**
+ * An abstract representation of a cloud service implementation provided by a cloud platform.
+ */
+interface ServiceProvider : Identity {
+    /**
+     * The unique identifier of the service implementation.
+     */
+    override val uid: UUID
+
+    /**
+     * The name of the service implementation.
+     */
+    override val name: String
+
+    /**
+     * The set of services provided by this [ServiceProvider].
+     */
+    val provides: Set<Service<*>>
+
+    /**
+     * The dependencies of the service implementation.
+     */
+    val dependencies: Set<Service<*>>
+
+    /**
+     * Build the runtime [Behavior] for this service.
+     *
+     * @param zone The zone model for which the service should be build.
+     * @param zoneRef The runtime reference to the zone's actor for communication.
+     * @param main The channel on which the service should listen.
+     */
+    suspend operator fun invoke(ctx: ProcessContext, zone: Zone, zoneRef: SendRef<ZoneMessage>, main: Channel<Any>)
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/provisioning/ProvisioningService.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/provisioning/ProvisioningService.kt
new file mode 100644
index 00000000..604e1942
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/provisioning/ProvisioningService.kt
@@ -0,0 +1,76 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.services.provisioning
+
+import com.atlarge.odcsim.SendRef
+import com.atlarge.opendc.core.services.AbstractService
+import com.atlarge.opendc.core.services.Service
+import com.atlarge.opendc.core.services.ServiceProvider
+import com.atlarge.opendc.core.services.resources.HostView
+import java.util.UUID
+
+/**
+ * A cloud platform service that provisions the native resources on the platform.
+ *
+ * This service assumes control over all hosts in its [Zone].
+ */
+abstract class ProvisioningService : ServiceProvider {
+    override val provides: Set<Service<*>> = setOf(ProvisioningService)
+
+    /**
+     * The service key of the provisioner service.
+     */
+    companion object : AbstractService<ProvisioningMessage>(UUID.randomUUID(), "provisioner")
+}
+
+/**
+ * A message protocol for communicating to the resource provisioner.
+ */
+sealed class ProvisioningMessage {
+    /**
+     * Request the specified number of resources from the provisioner.
+     *
+     * @property numHosts The number of hosts to request from the provisioner.
+     * @property replyTo The actor to reply to.
+     */
+    data class Request(val numHosts: Int, val replyTo: SendRef<ProvisioningResponse.Lease>) : ProvisioningMessage()
+
+    /**
+     * Release the specified resource [ProvisioningResponse.Lease].
+     *
+     * @property lease The lease to release.
+     */
+    data class Release(val lease: ProvisioningResponse.Lease) : ProvisioningMessage()
+}
+
+/**
+ * A message protocol used by the resource provisioner to respond to [ProvisioningMessage]s.
+ */
+sealed class ProvisioningResponse {
+    /**
+     * A lease for the specified hosts.
+     */
+    data class Lease(val hosts: List<HostView>) : ProvisioningResponse()
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/provisioning/SimpleProvisioningService.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/provisioning/SimpleProvisioningService.kt
new file mode 100644
index 00000000..5f77e1a1
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/provisioning/SimpleProvisioningService.kt
@@ -0,0 +1,107 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.services.provisioning
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.Channel
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.SendRef
+import com.atlarge.odcsim.ask
+import com.atlarge.odcsim.sendOnce
+import com.atlarge.opendc.core.Zone
+import com.atlarge.opendc.core.ZoneMessage
+import com.atlarge.opendc.core.find
+import com.atlarge.opendc.core.resources.compute.MachineRef
+import com.atlarge.opendc.core.services.Service
+import com.atlarge.opendc.core.services.resources.HostView
+import com.atlarge.opendc.core.services.resources.ResourceManagementMessage
+import com.atlarge.opendc.core.services.resources.ResourceManagementResponse
+import com.atlarge.opendc.core.services.resources.ResourceManagementService
+import java.util.ArrayDeque
+import java.util.UUID
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.isActive
+
+/**
+ * A cloud platform service that provisions the native resources on the platform.
+ *
+ * This service assumes control over all hosts in its [Zone].
+ */
+object SimpleProvisioningService : ProvisioningService() {
+    override val uid: UUID = UUID.randomUUID()
+    override val name: String = "simple-provisioner"
+    override val dependencies: Set<Service<*>> = setOf(ResourceManagementService)
+
+    /**
+     * Build the runtime [Behavior] for the resource provisioner, responding to messages of shape [ProvisioningMessage].
+     */
+    override suspend fun invoke(ctx: ProcessContext, zone: Zone, zoneRef: SendRef<ZoneMessage>, main: Channel<Any>) {
+        val inlet = ctx.listen(main.receive)
+        val manager = zoneRef.find(ResourceManagementService)
+
+        delay(10)
+
+        val hosts = mutableMapOf<MachineRef, HostView>()
+        val available = ArrayDeque<HostView>()
+        val leases = mutableSetOf<ProvisioningResponse.Lease>()
+
+        // Subscribe to all machines in the zone
+        for (cluster in zone.clusters) {
+            for (host in cluster.hosts) {
+                val msg: ResourceManagementResponse.Listing = manager.ask { ResourceManagementMessage.Lookup(host, it) }
+                if (msg.instance != null) {
+                    hosts[msg.instance.ref] = msg.instance
+                    available.add(msg.instance)
+                }
+            }
+        }
+
+        coroutineScope {
+            while (isActive) {
+                when (val msg = inlet.receive()) {
+                    is ProvisioningMessage.Request -> {
+                        println("Provisioning ${msg.numHosts} hosts")
+                        val leaseHosts = mutableListOf<HostView>()
+                        while (available.isNotEmpty() && leaseHosts.size < msg.numHosts) {
+                            leaseHosts += available.poll()
+                        }
+                        val lease = ProvisioningResponse.Lease(leaseHosts)
+                        leases += lease
+                        msg.replyTo.sendOnce(lease)
+                    }
+                    is ProvisioningMessage.Release -> {
+                        val lease = msg.lease
+                        if (lease in leases) {
+                            return@coroutineScope
+                        }
+                        available.addAll(lease.hosts)
+                        leases -= lease
+                    }
+                }
+            }
+        }
+    }
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/resources/HostView.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/resources/HostView.kt
new file mode 100644
index 00000000..60dd2eb9
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/resources/HostView.kt
@@ -0,0 +1,42 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.services.resources
+
+import com.atlarge.opendc.core.resources.compute.MachineRef
+import com.atlarge.opendc.core.resources.compute.MachineStatus
+import com.atlarge.opendc.core.resources.compute.host.Host
+
+/**
+ * The dynamic information of a [Host] instance that is being tracked by the [ResourceManagementService]. This means
+ * that information may not be up-to-date.
+ *
+ * @property host The static information of the host.
+ * @property ref The reference to the host's actor.
+ * @property status The status of the machine.
+ */
+data class HostView(val host: Host, val ref: MachineRef, val status: MachineStatus = MachineStatus.HALT) {
+    override fun equals(other: Any?): Boolean = other is HostView && host.uid == other.host.uid
+    override fun hashCode(): Int = host.uid.hashCode()
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/resources/ResourceManagementService.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/resources/ResourceManagementService.kt
new file mode 100644
index 00000000..cc032952
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/services/resources/ResourceManagementService.kt
@@ -0,0 +1,120 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.services.resources
+
+import com.atlarge.odcsim.Channel
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.SendRef
+import com.atlarge.odcsim.sendOnce
+import com.atlarge.opendc.core.Zone
+import com.atlarge.opendc.core.ZoneMessage
+import com.atlarge.opendc.core.resources.compute.MachineRef
+import com.atlarge.opendc.core.resources.compute.MachineStatus
+import com.atlarge.opendc.core.resources.compute.host.Host
+import com.atlarge.opendc.core.resources.compute.supervision.MachineSupervisionEvent
+import com.atlarge.opendc.core.services.Service
+import com.atlarge.opendc.core.services.ServiceProvider
+import java.util.UUID
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.isActive
+
+/**
+ * A cloud platform service that manages the native resources on the platform.
+ *
+ * This service assumes control over all hosts in its [Zone].
+ */
+object ResourceManagementService : ServiceProvider, Service<ResourceManagementMessage> {
+    override val uid: UUID = UUID.randomUUID()
+    override val name: String = "resource-manager"
+    override val provides: Set<Service<*>> = setOf(ResourceManagementService)
+    override val dependencies: Set<Service<*>> = emptySet()
+
+    /**
+     * Build the runtime behavior of the [ResourceManagementService].
+     */
+    override suspend fun invoke(ctx: ProcessContext, zone: Zone, zoneRef: SendRef<ZoneMessage>, main: Channel<Any>) {
+        // Launch the clusters of the zone
+        for (cluster in zone.clusters) {
+            ctx.spawn({ cluster(it, main.send) }, name = "${cluster.name}-${cluster.uid}")
+        }
+
+        val hosts = mutableMapOf<MachineRef, HostView>()
+        val inlet = ctx.listen(main.receive)
+
+        coroutineScope {
+            while (isActive) {
+                when (val msg = inlet.receive()) {
+                    is MachineSupervisionEvent.Announce -> {
+                        val host = msg.machine as? Host
+                        if (host != null) {
+                            hosts[msg.ref] = HostView(host, msg.ref)
+                        }
+                    }
+                    is MachineSupervisionEvent.Up -> {
+                        hosts.computeIfPresent(msg.ref) { _, value ->
+                            value.copy(status = MachineStatus.RUNNING)
+                        }
+                    }
+                    is ResourceManagementMessage.Lookup -> {
+                        msg.replyTo.sendOnce(ResourceManagementResponse.Listing(hosts.values.find { it.host == msg.host }))
+                    }
+                }
+            }
+        }
+    }
+}
+
+/**
+ * A reference to the resource manager of a zone.
+ */
+typealias ResourceManagerRef = SendRef<ResourceManagementMessage>
+
+/**
+ * A message protocol for communicating to the resource manager.
+ */
+sealed class ResourceManagementMessage {
+    /**
+     * Lookup the specified [Host].
+     *
+     * @property host The host to lookup.
+     * @property replyTo The address to sent the response to.
+     */
+    data class Lookup(
+        val host: Host,
+        val replyTo: SendRef<ResourceManagementResponse.Listing>
+    ) : ResourceManagementMessage()
+}
+
+/**
+ * A message protocol used by the resource manager to respond to [ResourceManagementMessage]s.
+ */
+sealed class ResourceManagementResponse {
+    /**
+     * A response to a [ResourceManagementMessage.Lookup] request.
+     *
+     * @property instance The instance that was found or `null` if it does not exist.
+     */
+    data class Listing(val instance: HostView?) : ResourceManagementResponse()
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/Workload.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/Workload.kt
new file mode 100644
index 00000000..def5d6e4
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/Workload.kt
@@ -0,0 +1,39 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.workload
+
+import com.atlarge.opendc.core.Identity
+import com.atlarge.opendc.core.User
+
+/**
+ * A high-level abstraction that represents the actual work that a set of compute resources perform, such
+ * as running an application on a machine or a whole workflow running multiple tasks on numerous machines.
+ */
+interface Workload : Identity {
+    /**
+     * The owner of this workload.
+     */
+    val owner: User
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/Application.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/Application.kt
new file mode 100644
index 00000000..d1ccd347
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/Application.kt
@@ -0,0 +1,49 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.workload.application
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.ReceiveRef
+import com.atlarge.opendc.core.workload.Workload
+
+/**
+ * A generic representation of a workload that can directly be executed by physical or virtual compute resources,
+ * such as a web server application.
+ */
+interface Application : Workload {
+    /**
+     * The number of processing elements required by the task.
+     */
+    val cores: Int
+
+    /**
+     * Build the runtime [Behavior] of an application, accepting messages of [ProcessMessage].
+     *
+     * This is a model for the runtime behavior of an application instance (process) that describes how an application
+     * instance consumes the allocated resources on a machine.
+     */
+    suspend operator fun invoke(ctx: ProcessContext, pid: Pid, main: ReceiveRef<ProcessMessage>)
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/FlopsApplication.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/FlopsApplication.kt
new file mode 100644
index 00000000..a2dbacf1
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/FlopsApplication.kt
@@ -0,0 +1,114 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.workload.application
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.ReceiveRef
+import com.atlarge.odcsim.sendOnce
+import com.atlarge.opendc.core.User
+import com.atlarge.opendc.core.resources.compute.ProcessingElement
+import java.util.UUID
+import kotlin.math.ceil
+import kotlin.math.min
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.isActive
+
+/**
+ * An [Application] implementation that models applications performing a static number of floating point operations
+ * ([flops]) on a compute resource.
+ *
+ * @property uid A unique identifier for this application.
+ * @property name The name of the application.
+ * @property owner The owner of this application.
+ * @property cores The number of cores needed for this application.
+ * @property flops The number of floating point operations to perform for this task.
+ */
+class FlopsApplication(
+    override val uid: UUID,
+    override val name: String,
+    override val owner: User,
+    override val cores: Int,
+    val flops: Long
+) : Application {
+
+    init {
+        require(flops >= 0) { "Negative number of flops" }
+    }
+
+    /**
+     * Build the runtime [Behavior] based on a number of floating point operations to execute.
+     */
+    override suspend fun invoke(ctx: ProcessContext, pid: Pid, main: ReceiveRef<ProcessMessage>) {
+        val inlet = ctx.listen(main)
+        var remaining = flops
+        var start: Long = 0
+        lateinit var allocation: Map<ProcessingElement, Double>
+
+        val created = inlet.receive() as ProcessMessage.Setup
+        val ref = created.ref
+
+        ref.sendOnce(ProcessEvent.Ready(pid))
+
+        suspend fun processAllocation(resources: Map<ProcessingElement, Double>, until: Long) {
+            start = ctx.clock.millis()
+            allocation = resources
+                .asSequence()
+                .take(cores)
+                .associateBy({ it.key }, { it.value })
+
+            val speed = allocation.asSequence()
+                .map { (key, value) -> key.unit.clockRate * value }
+                .average()
+            val finishedAt = ceil(ctx.clock.millis() + remaining / speed).toLong()
+            ref.sendOnce(ProcessEvent.Consume(pid, allocation, min(finishedAt, until)))
+        }
+
+        var msg = inlet.receive() as ProcessMessage.Allocation
+        processAllocation(msg.resources, msg.until)
+
+        coroutineScope {
+            while (isActive) {
+                msg = inlet.receive() as ProcessMessage.Allocation
+
+                /* Compute the consumption of flops */
+                val consumed = allocation.asSequence()
+                    .map { (key, value) -> key.unit.clockRate * value * (ctx.clock.millis() - start) }
+                    .sum()
+                // Ceil to prevent consumed flops being rounded to 0
+                remaining -= ceil(consumed).toLong()
+
+                /* Test whether all flops have been consumed and the task is finished */
+                if (remaining <= 0) {
+                    ref.sendOnce(ProcessEvent.Exit(pid, 0))
+                    break
+                }
+                processAllocation(msg.resources, msg.until)
+            }
+        }
+
+        inlet.close()
+    }
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/Process.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/Process.kt
new file mode 100644
index 00000000..fc70b924
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/Process.kt
@@ -0,0 +1,90 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.workload.application
+
+import com.atlarge.odcsim.SendRef
+import com.atlarge.opendc.core.resources.compute.Machine
+import com.atlarge.opendc.core.resources.compute.ProcessingElement
+
+/**
+ * The process id (pid) is a reference to the application instance (process) that accepts messages of
+ * type [ProcessMessage].
+ */
+typealias Pid = SendRef<ProcessMessage>
+
+/**
+ * A message protocol for actors to communicate with task instances (called processes).
+ */
+sealed class ProcessMessage {
+    /**
+     * Indicate that the task should be installed to the specified machine.
+     *
+     * @property machine The machine to install the task.
+     * @property ref The reference to the machine instance.
+     */
+    data class Setup(val machine: Machine, val ref: SendRef<ProcessEvent>) : ProcessMessage()
+
+    /**
+     * Indicate an allocation of compute resources on a machine for a certain duration.
+     * The task may assume that the reservation occurs after installation on the same machine.
+     *
+     * @property resources The cpu cores (and the utilization percentages) allocated for the task.
+     * @property until The point in time till which the reservation is valid.
+     */
+    data class Allocation(val resources: Map<ProcessingElement, Double>, val until: Long) : ProcessMessage()
+}
+
+/**
+ * The message protocol used by application instances respond to [ProcessMessage]s.
+ */
+sealed class ProcessEvent {
+    /**
+     * Indicate that the process is ready to start processing.
+     *
+     * @property pid A reference to the application instance.
+     */
+    data class Ready(val pid: Pid) : ProcessEvent()
+
+    /**
+     * Indicate the estimated resource utilization of the task until a specified point in time.
+     *
+     * @property pid A reference to the application instance of the represented utilization.
+     * @property utilization The utilization of the cpu cores as a percentage.
+     * @property until The point in time until which the utilization is valid.
+     */
+    data class Consume(
+        val pid: Pid,
+        val utilization: Map<ProcessingElement, Double>,
+        val until: Long
+    ) : ProcessEvent()
+
+    /**
+     * Indicate that a process has been terminated.
+     *
+     * @property pid A reference to the application instance.
+     * @property status The exit code of the task, where zero means successful.
+     */
+    data class Exit(val pid: Pid, val status: Int) : ProcessEvent()
+}
diff --git a/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/ProcessSupervisor.kt b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/ProcessSupervisor.kt
new file mode 100644
index 00000000..fefd6c88
--- /dev/null
+++ b/opendc/opendc-core/src/main/kotlin/com/atlarge/opendc/core/workload/application/ProcessSupervisor.kt
@@ -0,0 +1,83 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2019 atlarge-research
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package com.atlarge.opendc.core.workload.application
+
+import com.atlarge.odcsim.Behavior
+import com.atlarge.odcsim.ProcessContext
+import com.atlarge.odcsim.ReceiveRef
+import com.atlarge.opendc.core.resources.compute.ProcessingElement
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.isActive
+
+/**
+ * An interface for supervising processes.
+ */
+interface ProcessSupervisor {
+    /**
+     * This method is invoked when the setup of an application completed successfully.
+     *
+     * @param pid The process id of the process that has been initialized.
+     */
+    fun onReady(pid: Pid) {}
+
+    /**
+     * This method is invoked when a process informs the machine that it is running with the
+     * estimated resource utilization until a specified point in time.
+     *
+     * @param pid The process id of the process that is running.
+     * @param utilization The utilization of the cpu cores as a percentage.
+     * @param until The point in time until which the utilization is valid.
+     */
+    fun onConsume(pid: Pid, utilization: Map<ProcessingElement, Double>, until: Long) {}
+
+    /**
+     * This method is invoked when a process exits.
+     *
+     * @property pid A reference to the application instance.
+     * @property status The exit code of the task, where zero means successful.
+     */
+    fun onExit(pid: Pid, status: Int) {}
+
+    companion object {
+        /**
+         * Create the [Behavior] for a [ProcessSupervisor].
+         *
+         * @param supervisor The supervisor to create the behavior for.
+         */
+        suspend operator fun invoke(ctx: ProcessContext, supervisor: ProcessSupervisor, main: ReceiveRef<ProcessEvent>) {
+            val inlet = ctx.listen(main)
+            coroutineScope {
+                while (isActive) {
+                    when (val msg = inlet.receive()) {
+                        is ProcessEvent.Ready -> supervisor.onReady(msg.pid)
+                        is ProcessEvent.Consume -> supervisor.onConsume(msg.pid, msg.utilization, msg.until)
+                        is ProcessEvent.Exit -> supervisor.onExit(msg.pid, msg.status)
+                    }
+                }
+            }
+            inlet.close()
+        }
+    }
+}