Create initial architecture

This change adds the initial architecture of the Kotlin rewrite. The
representation of the topology of a cloud network is unfinished and I am
still not sure what would be the best way to represent it.

24 files changed, 1001 insertions, 0 deletions

diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Experiment.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Experiment.kt
new file mode 100644
index 00000000..c91f55da
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Experiment.kt
@@ -0,0 +1,32 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.experiment
+
+/**
+ * A simulation of multiple simultaneous workloads running on top of a topology.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+class Experiment {}
\ No newline at end of file
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/ExperimentRunner.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/ExperimentRunner.kt
new file mode 100644
index 00000000..43b9ddac
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/ExperimentRunner.kt
@@ -0,0 +1,32 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.experiment
+
+/**
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface ExperimentRunner {
+}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Job.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Job.kt
new file mode 100644
index 00000000..8b225bd8
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Job.kt
@@ -0,0 +1,34 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.experiment
+
+/**
+ * A job that is submitted to a cloud network, which consists of one or multiple [Task]s.
+ *
+ * @param owner The user to which the job belongs.
+ * @param tasks The tasks of which the job consists.
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+data class Job(val owner: User, val tasks: Collection<Task>)
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Scheduler.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Scheduler.kt
new file mode 100644
index 00000000..4e000af3
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Scheduler.kt
@@ -0,0 +1,43 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.experiment
+
+import nl.tudelft.opendc.topology.Entity
+import nl.tudelft.opendc.topology.Node
+
+/**
+ * A task scheduler that is coupled to an [Entity] in the topology of the cloud network.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface Scheduler<in E: Entity> {
+	/**
+	 * Schedule the given jobs for the given entity.
+	 *
+	 * @param node The node in the cloud network topology representing the entity.
+	 * @param jobs The jobs that have been submitted to the cloud network.
+	 */
+	fun schedule(node: Node<E>, jobs: Set<Job>)
+}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Task.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Task.kt
new file mode 100644
index 00000000..f425ccac
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/Task.kt
@@ -0,0 +1,64 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.experiment
+
+/**
+ * A task represents some computation that is part of a [Job].
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+data class Task(
+	val id: Int,
+	val dependencies: Set<Task>,
+	val flops: Long
+) {
+	/**
+	 * The remaining amount of flops to compute.
+	 */
+	var remaining: Long = flops
+		private set
+
+	/**
+	 * A flag to indicate whether the task is finished.
+	 */
+	var finished: Boolean = false
+		private set
+
+	/**
+	 * Consume the given amount of flops of this task.
+	 *
+	 * @param flops The total amount of flops to consume.
+	 */
+	fun consume(flops: Long) {
+		if (finished)
+			return
+		if (remaining <= flops) {
+			finished = true
+			remaining = 0
+		} else {
+			remaining -= flops
+		}
+	}
+}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/User.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/User.kt
new file mode 100644
index 00000000..a818fc5f
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/experiment/User.kt
@@ -0,0 +1,37 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.experiment
+
+import nl.tudelft.opendc.topology.Node
+
+/**
+ * A user of a cloud network that provides [Job]s for the simulation.
+ *
+ * <p>Each [User] in a simulation has its own logical view of the cloud network which is used to route its jobs in the
+ * physical network.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+data class User(val id: Int, val name: String, val view: Node<*>) {}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/sampler/Sampler.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/sampler/Sampler.kt
new file mode 100644
index 00000000..a89486ec
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/sampler/Sampler.kt
@@ -0,0 +1,39 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.sampler
+
+/**
+ * A sampler generates data points (samples) of the simulation based on the events that occur to [Entity] instances that
+ * are part of the simulation.
+ *
+ * <p>[Sampler]s work by observing [Entity] instances in the simulation and transforming this stream of events into a
+ * stream of data points.
+ *
+ * <p>An example would be a sampler that tracks [Machine] occupation per time unit, which is achieved by observing the
+ * [Entity]'s event stream and filtering for [JobAssignment] events.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface Sampler
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/simulator/Simulator.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/simulator/Simulator.kt
new file mode 100644
index 00000000..c1ea6b2d
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/simulator/Simulator.kt
@@ -0,0 +1,68 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.simulator
+
+import nl.tudelft.opendc.topology.Entity
+
+/**
+ * A simulator that simulates a single entity in the topology of a cloud network.
+ *
+ * @param entity The entity to simulate.
+ * @param ctx The context in which the simulation is run.
+ * @param <E> The type of entity to simulate.
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+abstract class Simulator<out E: Entity>(val entity: E, val ctx: SimulatorContext) {
+	/**
+	 * This method is invoked at least once before a tick. This allows the [Simulator] to setup its state before a tick
+	 * event.
+	 *
+	 * <p>The pre-tick consists of multiple sub-cycles in which all messages which have been sent
+	 * in the previous sub-cycle can optionally be processed in the sub-cycle by the receiving [Simulator].
+	 */
+	fun preTick() {}
+
+	/**
+	 * This method is invoked once per tick, which allows the [Simulator] to process events and simulate an entity in a
+	 * cloud network.
+	 */
+	fun tick() {}
+
+	/**
+	 * This method is invoked at least once per tick. This allows the [Simulator] to do work after a tick.
+	 *
+	 * <p>Like the pre-tick, the post-tick consists of multiple sub-cycles in which all messages which have been sent
+	 * in the previous sub-cycle can optionally be processed in the sub-cycle by the receiving [Simulator].
+	 */
+	fun postTick() {}
+
+	/**
+	 * Send the given message to the given [Entity] for processing.
+	 *
+	 * @param destination The entity to send the message to.
+	 * @param message The message to send to the entity.
+	 */
+	fun send(destination: Entity, message: Any?) {}
+}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/simulator/SimulatorContext.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/simulator/SimulatorContext.kt
new file mode 100644
index 00000000..e7729bea
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/simulator/SimulatorContext.kt
@@ -0,0 +1,37 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.simulator
+
+/**
+ * The context in which a [Simulator] runs.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+class SimulatorContext {
+	/**
+	 * The current tick of the simulation.
+	 */
+	var tick: Long = 0
+}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Edge.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Edge.kt
new file mode 100644
index 00000000..05541775
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Edge.kt
@@ -0,0 +1,79 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology
+
+/**
+ * An edge that represents a connection between exactly two instances of [Node].
+ * Instances of [Edge] may be either directed or undirected.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface Edge<out T> {
+	/**
+	 * The label of this edge.
+	 */
+	val label: T
+
+	/**
+	 * An [Edge] that is directed, having a source and destination [Node].
+	 */
+	interface Directed<out T>: Edge<T> {
+		/**
+		 * The source of the edge.
+		 */
+		val from: Node<*>
+
+		/**
+		 * The destination of the edge.
+		 */
+		val to: Node<*>
+	}
+
+	/**
+	 * An [Edge] that is undirected.
+	 */
+	interface Undirected<out T>: Edge<T>
+
+	/**
+	 * Return the [Node] at the opposite end of this [Edge] from the
+	 * specified node.
+	 *
+	 * Throws [IllegalArgumentException] if <code>node</code> is
+	 * not incident to this edge.
+	 *
+	 * @param node The node to get the opposite of for this edge pair.
+	 * @return The node at the opposite end of this edge from the specified node.
+	 * @throws IllegalArgumentException if <code>node</code> is not incident to this edge.
+	 */
+	fun opposite(node: Node<*>): Node<*>
+
+	/**
+	 * Return a [Pair] representing this edge consisting of both incident nodes.
+	 * Note that the pair is in no particular order.
+	 *
+	 * @return The edge represented as pair of both incident nodes.
+	 */
+	fun endpoints(): Pair<Node<*>, Node<*>>
+}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Entity.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Entity.kt
new file mode 100644
index 00000000..37423959
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Entity.kt
@@ -0,0 +1,37 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology
+
+/**
+ * An entity in a cloud network.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface Entity {
+	/**
+	 * A unique identifier of this node within the topology represented as a [Int].
+	 */
+	val id: Int
+}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Graph.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Graph.kt
new file mode 100644
index 00000000..1cbbdb95
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Graph.kt
@@ -0,0 +1,47 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology
+
+/**
+ * A graph data structure which represents the logical topology of a cloud network consisting of one or more data
+ * centers.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface Graph {
+	/**
+	 * Add the given [Node] to this graph.
+	 *
+	 * @param node The node to add.
+	 */
+	fun addNode(node: Node<*>)
+
+	/**
+	 * Add the given [Edge] to this graph.
+	 *
+	 * @param edge The edge to add.
+	 */
+	fun addEdge(edge: Edge<*>)
+}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Node.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Node.kt
new file mode 100644
index 00000000..da0d183c
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/Node.kt
@@ -0,0 +1,51 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology
+
+/**
+ * A node in the logical topology of a cloud network, representing some [Entity].
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface Node<out E: Entity> {
+	/**
+	 * The [Entity] this node represents.
+	 */
+	val entity: E
+
+	/**
+	 * Return the set of incoming edges of this node.
+	 *
+	 * @return All edges whose destination is this node.
+	 */
+	fun incomingEdges(): Set<Edge<*>>
+
+	/**
+	 * Return the set of outgoing edges of this node.
+	 *
+	 * @return  All edges whose source is this node.
+	 */
+	fun outgoingEdges(): Set<Edge<*>>
+}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/DataCenter.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/DataCenter.kt
new file mode 100644
index 00000000..56d0366e
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/DataCenter.kt
@@ -0,0 +1,35 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.container
+
+import nl.tudelft.opendc.topology.Entity
+
+/**
+ * A representation of a facility used to house computer systems and associated components.
+ *
+ * @param id The unique identifier of this entity.
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+class DataCenter(override val id: Int): Entity
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/rack/Rack.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/rack/Rack.kt
new file mode 100644
index 00000000..b64da3bb
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/rack/Rack.kt
@@ -0,0 +1,36 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.container.rack
+
+import nl.tudelft.opendc.topology.Entity
+
+/**
+ * A type of physical steel and electronic framework that is designed to house servers, networking devices, cables and
+ * other data center computing equipment.
+ *
+ * @param id The unique identifier of this entity.
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+data class Rack(override val id: Int): Entity
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/rack/Slot.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/rack/Slot.kt
new file mode 100644
index 00000000..ce371e24
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/rack/Slot.kt
@@ -0,0 +1,32 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.container.rack
+
+/**
+ * This class represents a slot in a [Rack] of [Machine]s.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+data class Slot(val index: Int)
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/room/Room.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/room/Room.kt
new file mode 100644
index 00000000..0b73963d
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/container/room/Room.kt
@@ -0,0 +1,35 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.container.room
+
+import nl.tudelft.opendc.topology.Entity
+
+/**
+ * A physical room in a data center which contains [Entity]s.
+ *
+ * @param id The unique identifier of this entity.
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+abstract class Room(override val id: Int): Entity
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/Cpu.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/Cpu.kt
new file mode 100644
index 00000000..612af5ce
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/Cpu.kt
@@ -0,0 +1,37 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.machine
+
+/**
+ * A central processing unit.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+data class Cpu(
+	override val id: Int,
+	override val speed: Int,
+	override val cores: Int,
+	override val energyConsumption: Int
+): ProcessingUnit
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/Gpu.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/Gpu.kt
new file mode 100644
index 00000000..f4851f9c
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/Gpu.kt
@@ -0,0 +1,37 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.machine
+
+/**
+ * A graphics processing unit.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+data class Gpu(
+	override val id: Int,
+	override val speed: Int,
+	override val cores: Int,
+	override val energyConsumption: Int
+): ProcessingUnit
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/Machine.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/Machine.kt
new file mode 100644
index 00000000..f50fc717
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/Machine.kt
@@ -0,0 +1,36 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.machine
+
+import nl.tudelft.opendc.topology.Entity
+
+/**
+ * A Physical Machine (PM) inside a rack of a data center. It has a speed, and can be given a workload on which it will
+ * work until finished or interrupted.
+ *
+ * @param id The unique identifier of this entity.
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+data class Machine(override val id: Int): Entity
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/ProcessingUnit.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/ProcessingUnit.kt
new file mode 100644
index 00000000..e7194a80
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/machine/ProcessingUnit.kt
@@ -0,0 +1,49 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.machine
+
+import nl.tudelft.opendc.topology.Entity
+
+/**
+ * An interface representing a generic processing unit which is placed into a [Machine].
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface ProcessingUnit: Entity {
+	/**
+	 * The speed of this [ProcessingUnit] per core.
+	 */
+	val speed: Int
+
+	/**
+	 * The amount of cores within this [ProcessingUnit].
+	 */
+	val cores: Int
+
+	/**
+	 * The energy consumption of this [ProcessingUnit] in Kj/s.
+	 */
+	val energyConsumption: Int
+}
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/network/NetworkUnit.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/network/NetworkUnit.kt
new file mode 100644
index 00000000..c4a81d9b
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/network/NetworkUnit.kt
@@ -0,0 +1,34 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.network
+
+import nl.tudelft.opendc.topology.Entity
+
+/**
+ * A generic interface for a network unit in a cloud network.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface NetworkUnit: Entity
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/power/PowerUnit.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/power/PowerUnit.kt
new file mode 100644
index 00000000..19eeaea3
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/power/PowerUnit.kt
@@ -0,0 +1,36 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.power
+
+import nl.tudelft.opendc.topology.Entity
+
+/**
+ * An [Entity] which provides power for other entities a cloud network to run.
+ *
+ * @param id The unique identifier of the [Entity].
+ * @param output The output of the power unit in Watts.
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+data class PowerUnit(override val id: Int, val output: Double): Entity
diff --git a/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/storage/StorageUnit.kt b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/storage/StorageUnit.kt
new file mode 100644
index 00000000..d601e027
--- /dev/null
+++ b/opendc-core/src/main/kotlin/nl/tudelft/opendc/topology/storage/StorageUnit.kt
@@ -0,0 +1,34 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2017 tudelft-atlarge
+ *
+ * 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 nl.tudelft.opendc.topology.storage
+
+import nl.tudelft.opendc.topology.Entity
+
+/**
+ * A generic interface for a storage unit in a cloud network.
+ *
+ * @author Fabian Mastenbroek (f.s.mastenbroek@student.tudelft.nl)
+ */
+interface StorageUnit: Entity