feat(compute): Support filtering hosts based on CPU capacity

This change allows users to create servers with a smaller CPU capacity
than the host, by specifying the CPU capacity via metadata. This also
allows filtering hosts based on their available CPU capacity.

6 files changed, 90 insertions, 5 deletions

diff --git a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/driver/HostModel.kt b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/driver/HostModel.kt
index fc092a3f..f3b94e3d 100644
--- a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/driver/HostModel.kt
+++ b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/driver/HostModel.kt
@@ -25,7 +25,12 @@ package org.opendc.compute.service.driver
 /**
  * Describes the static machine properties of the host.
  *
+ * @property cpuCapacity The total CPU capacity of the host in MHz.
  * @property cpuCount The number of logical processing cores available for this host.
- * @property memorySize The amount of memory available for this host in MB.
+ * @property memoryCapacity The amount of memory available for this host in MB.
  */
-public data class HostModel(public val cpuCount: Int, public val memorySize: Long)
+public data class HostModel(
+    public val cpuCapacity: Double,
+    public val cpuCount: Int,
+    public val memoryCapacity: Long
+)
diff --git a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/ComputeServiceImpl.kt b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/ComputeServiceImpl.kt
index 57e70fcd..2a07a208 100644
--- a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/ComputeServiceImpl.kt
+++ b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/ComputeServiceImpl.kt
@@ -298,7 +298,7 @@ internal class ComputeServiceImpl(
 
         val hv = HostView(host)
         maxCores = max(maxCores, host.model.cpuCount)
-        maxMemory = max(maxMemory, host.model.memorySize)
+        maxMemory = max(maxMemory, host.model.memoryCapacity)
         hostToView[host] = hv
 
         if (host.state == HostState.UP) {
diff --git a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/HostView.kt b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/HostView.kt
index e2f33f11..0876209a 100644
--- a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/HostView.kt
+++ b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/internal/HostView.kt
@@ -37,7 +37,7 @@ public class HostView(public val host: Host) {
         get() = host.uid
 
     public var instanceCount: Int = 0
-    public var availableMemory: Long = host.model.memorySize
+    public var availableMemory: Long = host.model.memoryCapacity
     public var provisionedCores: Int = 0
 
     override fun toString(): String = "HostView[host=$host]"
diff --git a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/scheduler/filters/RamFilter.kt b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/scheduler/filters/RamFilter.kt
index a470a453..8a7a646c 100644
--- a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/scheduler/filters/RamFilter.kt
+++ b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/scheduler/filters/RamFilter.kt
@@ -34,7 +34,7 @@ public class RamFilter(private val allocationRatio: Double) : HostFilter {
     override fun test(host: HostView, server: Server): Boolean {
         val requested = server.flavor.memorySize
         val available = host.availableMemory
-        val total = host.host.model.memorySize
+        val total = host.host.model.memoryCapacity
 
         // Do not allow an instance to overcommit against itself, only against
         // other instances.
diff --git a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/scheduler/filters/VCpuCapacityFilter.kt b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/scheduler/filters/VCpuCapacityFilter.kt
new file mode 100644
index 00000000..791710c8
--- /dev/null
+++ b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/scheduler/filters/VCpuCapacityFilter.kt
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2021 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 org.opendc.compute.service.scheduler.filters
+
+import org.opendc.compute.api.Server
+import org.opendc.compute.service.internal.HostView
+
+/**
+ * A [HostFilter] that filters hosts based on the vCPU speed requirements of a [Server] and the available
+ * capacity on the host.
+ */
+public class VCpuCapacityFilter : HostFilter {
+    override fun test(host: HostView, server: Server): Boolean {
+        val requiredCapacity = server.flavor.meta["cpu-capacity"] as? Double
+        val hostModel = host.host.model
+        val availableCapacity = hostModel.cpuCapacity / hostModel.cpuCount
+
+        return requiredCapacity == null || availableCapacity >= (requiredCapacity / server.flavor.cpuCount)
+    }
+}
diff --git a/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/scheduler/weights/VCpuCapacityWeigher.kt b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/scheduler/weights/VCpuCapacityWeigher.kt
new file mode 100644
index 00000000..a86226e2
--- /dev/null
+++ b/opendc-compute/opendc-compute-service/src/main/kotlin/org/opendc/compute/service/scheduler/weights/VCpuCapacityWeigher.kt
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2021 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 org.opendc.compute.service.scheduler.weights
+
+import org.opendc.compute.api.Server
+import org.opendc.compute.service.internal.HostView
+
+/**
+ * A [HostWeigher] that weighs the hosts based on the difference required vCPU capacity and the available CPU capacity.
+ */
+public class VCpuCapacityWeigher(override val multiplier: Double = 1.0) : HostWeigher {
+
+    override fun getWeight(host: HostView, server: Server): Double {
+        val model = host.host.model
+        val requiredCapacity = server.flavor.meta["cpu-capacity"] as? Double ?: 0.0
+        return model.cpuCapacity / model.cpuCount - requiredCapacity / server.flavor.cpuCount
+    }
+
+    override fun toString(): String = "VCpuWeigher"
+}