merge: Integrate v2.1 progress into public repository

This pull request integrates the changes planned for the v2.1 release of
OpenDC into the public Github repository in order to sync the progress
of both repositories.

3 files changed, 479 insertions, 55 deletions

diff --git a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt
index a6258845..564f9493 100644
--- a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt
+++ b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/ComputeServiceTest.kt
@@ -37,9 +37,10 @@ import org.opendc.compute.service.driver.HostListener
 import org.opendc.compute.service.driver.HostModel
 import org.opendc.compute.service.driver.HostState
 import org.opendc.compute.service.scheduler.FilterScheduler
-import org.opendc.compute.service.scheduler.filters.ComputeCapabilitiesFilter
 import org.opendc.compute.service.scheduler.filters.ComputeFilter
-import org.opendc.compute.service.scheduler.weights.MemoryWeigher
+import org.opendc.compute.service.scheduler.filters.RamFilter
+import org.opendc.compute.service.scheduler.filters.VCpuFilter
+import org.opendc.compute.service.scheduler.weights.RamWeigher
 import org.opendc.simulator.core.SimulationCoroutineScope
 import org.opendc.simulator.core.runBlockingSimulation
 import java.util.*
@@ -57,11 +58,10 @@ internal class ComputeServiceTest {
         scope = SimulationCoroutineScope()
         val clock = scope.clock
         val computeScheduler = FilterScheduler(
-            filters = listOf(ComputeFilter(), ComputeCapabilitiesFilter()),
-            weighers = listOf(MemoryWeigher() to -1.0)
+            filters = listOf(ComputeFilter(), VCpuFilter(allocationRatio = 1.0), RamFilter(allocationRatio = 1.0)),
+            weighers = listOf(RamWeigher())
         )
-        val meter = MeterProvider.noop().get("opendc-compute")
-        service = ComputeService(scope.coroutineContext, clock, meter, computeScheduler)
+        service = ComputeService(scope.coroutineContext, clock, MeterProvider.noop(), computeScheduler)
     }
 
     @Test
@@ -167,9 +167,9 @@ internal class ComputeServiceTest {
         val server = client.newServer("test", image, flavor, start = false)
 
         server.start()
-        delay(5 * 60 * 1000)
+        delay(5L * 60 * 1000)
         server.refresh()
-        assertEquals(ServerState.ERROR, server.state)
+        assertEquals(ServerState.TERMINATED, server.state)
     }
 
     @Test
@@ -180,9 +180,9 @@ internal class ComputeServiceTest {
         val server = client.newServer("test", image, flavor, start = false)
 
         server.start()
-        delay(5 * 60 * 1000)
+        delay(5L * 60 * 1000)
         server.refresh()
-        assertEquals(ServerState.ERROR, server.state)
+        assertEquals(ServerState.TERMINATED, server.state)
     }
 
     @Test
@@ -193,9 +193,9 @@ internal class ComputeServiceTest {
         val server = client.newServer("test", image, flavor, start = false)
 
         server.start()
-        delay(5 * 60 * 1000)
+        delay(5L * 60 * 1000)
         server.refresh()
-        assertEquals(ServerState.ERROR, server.state)
+        assertEquals(ServerState.TERMINATED, server.state)
     }
 
     @Test
@@ -207,7 +207,7 @@ internal class ComputeServiceTest {
 
         server.start()
         server.stop()
-        delay(5 * 60 * 1000)
+        delay(5L * 60 * 1000)
         server.refresh()
         assertEquals(ServerState.TERMINATED, server.state)
     }
@@ -228,7 +228,7 @@ internal class ComputeServiceTest {
         val server = client.newServer("test", image, flavor, start = false)
 
         server.start()
-        delay(10 * 60 * 1000)
+        delay(10L * 60 * 1000)
         server.refresh()
         assertEquals(ServerState.PROVISIONING, server.state)
 
@@ -254,12 +254,12 @@ internal class ComputeServiceTest {
         val server = client.newServer("test", image, flavor, start = false)
 
         server.start()
-        delay(5 * 60 * 1000)
+        delay(5L * 60 * 1000)
 
         every { host.state } returns HostState.UP
         listeners.forEach { it.onStateChanged(host, HostState.UP) }
 
-        delay(5 * 60 * 1000)
+        delay(5L * 60 * 1000)
         server.refresh()
         assertEquals(ServerState.PROVISIONING, server.state)
 
@@ -284,13 +284,13 @@ internal class ComputeServiceTest {
         val image = client.newImage("test")
         val server = client.newServer("test", image, flavor, start = false)
 
-        delay(5 * 60 * 1000)
+        delay(5L * 60 * 1000)
 
         every { host.state } returns HostState.DOWN
         listeners.forEach { it.onStateChanged(host, HostState.DOWN) }
 
         server.start()
-        delay(5 * 60 * 1000)
+        delay(5L * 60 * 1000)
         server.refresh()
         assertEquals(ServerState.PROVISIONING, server.state)
 
@@ -344,7 +344,7 @@ internal class ComputeServiceTest {
 
         // Start server
         server.start()
-        delay(5 * 60 * 1000)
+        delay(5L * 60 * 1000)
         coVerify { host.spawn(capture(slot), true) }
 
         listeners.forEach { it.onStateChanged(host, slot.captured, ServerState.RUNNING) }
@@ -383,7 +383,7 @@ internal class ComputeServiceTest {
         val server = client.newServer("test", image, flavor, start = false)
 
         server.start()
-        delay(5 * 60 * 1000)
+        delay(5L * 60 * 1000)
 
         server.refresh()
         assertEquals(ServerState.PROVISIONING, server.state)
diff --git a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/InternalServerTest.kt b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/InternalServerTest.kt
index 20ea8d20..dfd3bc67 100644
--- a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/InternalServerTest.kt
+++ b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/InternalServerTest.kt
@@ -47,8 +47,9 @@ class InternalServerTest {
     fun testEquality() {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
+
         val a = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
         val b = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
@@ -59,8 +60,8 @@ class InternalServerTest {
     fun testEqualityWithDifferentType() {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val a = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
         val b = mockk<Server>(relaxUnitFun = true)
@@ -73,8 +74,8 @@ class InternalServerTest {
     fun testInequalityWithDifferentType() {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val a = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
         val b = mockk<Server>(relaxUnitFun = true)
@@ -87,8 +88,8 @@ class InternalServerTest {
     fun testInequalityWithIncorrectType() {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val a = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
         assertNotEquals(a, Unit)
@@ -98,11 +99,11 @@ class InternalServerTest {
     fun testStartTerminatedServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
-        every { service.schedule(any()) } answers { ComputeServiceImpl.SchedulingRequest(it.invocation.args[0] as InternalServer) }
+        every { service.schedule(any()) } answers { ComputeServiceImpl.SchedulingRequest(it.invocation.args[0] as InternalServer, 0) }
 
         server.start()
 
@@ -114,8 +115,8 @@ class InternalServerTest {
     fun testStartDeletedServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
         server.state = ServerState.DELETED
@@ -127,8 +128,8 @@ class InternalServerTest {
     fun testStartProvisioningServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
         server.state = ServerState.PROVISIONING
@@ -142,8 +143,8 @@ class InternalServerTest {
     fun testStartRunningServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
         server.state = ServerState.RUNNING
@@ -157,10 +158,10 @@ class InternalServerTest {
     fun testStopProvisioningServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
-        val request = ComputeServiceImpl.SchedulingRequest(server)
+        val request = ComputeServiceImpl.SchedulingRequest(server, 0)
 
         every { service.schedule(any()) } returns request
 
@@ -175,8 +176,8 @@ class InternalServerTest {
     fun testStopTerminatedServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
         server.state = ServerState.TERMINATED
@@ -189,8 +190,8 @@ class InternalServerTest {
     fun testStopDeletedServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
         server.state = ServerState.DELETED
@@ -203,8 +204,8 @@ class InternalServerTest {
     fun testStopRunningServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>()
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
         val host = mockk<Host>(relaxUnitFun = true)
 
@@ -220,10 +221,10 @@ class InternalServerTest {
     fun testDeleteProvisioningServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>(relaxUnitFun = true)
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
-        val request = ComputeServiceImpl.SchedulingRequest(server)
+        val request = ComputeServiceImpl.SchedulingRequest(server, 0)
 
         every { service.schedule(any()) } returns request
 
@@ -239,8 +240,8 @@ class InternalServerTest {
     fun testDeleteTerminatedServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>(relaxUnitFun = true)
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
         server.state = ServerState.TERMINATED
@@ -255,8 +256,8 @@ class InternalServerTest {
     fun testDeleteDeletedServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>(relaxUnitFun = true)
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
 
         server.state = ServerState.DELETED
@@ -269,8 +270,8 @@ class InternalServerTest {
     fun testDeleteRunningServer() = runBlockingSimulation {
         val service = mockk<ComputeServiceImpl>(relaxUnitFun = true)
         val uid = UUID.randomUUID()
-        val flavor = mockk<InternalFlavor>()
-        val image = mockk<InternalImage>()
+        val flavor = mockFlavor()
+        val image = mockImage()
         val server = InternalServer(service, uid, "test", flavor, image, mutableMapOf(), mutableMapOf())
         val host = mockk<Host>(relaxUnitFun = true)
 
@@ -282,4 +283,20 @@ class InternalServerTest {
         coVerify { host.delete(server) }
         verify { service.delete(server) }
     }
+
+    private fun mockFlavor(): InternalFlavor {
+        val flavor = mockk<InternalFlavor>()
+        every { flavor.name } returns "c5.large"
+        every { flavor.uid } returns UUID.randomUUID()
+        every { flavor.cpuCount } returns 2
+        every { flavor.memorySize } returns 4096
+        return flavor
+    }
+
+    private fun mockImage(): InternalImage {
+        val image = mockk<InternalImage>()
+        every { image.name } returns "ubuntu-20.04"
+        every { image.uid } returns UUID.randomUUID()
+        return image
+    }
 }
diff --git a/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/scheduler/FilterSchedulerTest.kt b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/scheduler/FilterSchedulerTest.kt
new file mode 100644
index 00000000..cafd4498
--- /dev/null
+++ b/opendc-compute/opendc-compute-service/src/test/kotlin/org/opendc/compute/service/scheduler/FilterSchedulerTest.kt
@@ -0,0 +1,407 @@
+/*
+ * 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
+
+import io.mockk.every
+import io.mockk.mockk
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertNull
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertAll
+import org.junit.jupiter.api.assertThrows
+import org.opendc.compute.api.Server
+import org.opendc.compute.service.driver.HostModel
+import org.opendc.compute.service.driver.HostState
+import org.opendc.compute.service.internal.HostView
+import org.opendc.compute.service.scheduler.filters.ComputeFilter
+import org.opendc.compute.service.scheduler.filters.InstanceCountFilter
+import org.opendc.compute.service.scheduler.filters.RamFilter
+import org.opendc.compute.service.scheduler.filters.VCpuFilter
+import org.opendc.compute.service.scheduler.weights.CoreRamWeigher
+import org.opendc.compute.service.scheduler.weights.InstanceCountWeigher
+import org.opendc.compute.service.scheduler.weights.RamWeigher
+import org.opendc.compute.service.scheduler.weights.VCpuWeigher
+import java.util.*
+
+/**
+ * Test suite for the [FilterScheduler].
+ */
+internal class FilterSchedulerTest {
+    @Test
+    fun testInvalidSubsetSize() {
+        assertThrows<IllegalArgumentException> {
+            FilterScheduler(
+                filters = emptyList(),
+                weighers = emptyList(),
+                subsetSize = 0
+            )
+        }
+
+        assertThrows<IllegalArgumentException> {
+            FilterScheduler(
+                filters = emptyList(),
+                weighers = emptyList(),
+                subsetSize = -2
+            )
+        }
+    }
+
+    @Test
+    fun testNoHosts() {
+        val scheduler = FilterScheduler(
+            filters = emptyList(),
+            weighers = emptyList(),
+        )
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        assertNull(scheduler.select(server))
+    }
+
+    @Test
+    fun testNoFiltersAndSchedulers() {
+        val scheduler = FilterScheduler(
+            filters = emptyList(),
+            weighers = emptyList(),
+        )
+
+        val hostA = mockk<HostView>()
+        every { hostA.host.state } returns HostState.DOWN
+
+        val hostB = mockk<HostView>()
+        every { hostB.host.state } returns HostState.UP
+
+        scheduler.addHost(hostA)
+        scheduler.addHost(hostB)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        // Make sure we get the first host both times
+        assertAll(
+            { assertEquals(hostA, scheduler.select(server)) },
+            { assertEquals(hostA, scheduler.select(server)) }
+        )
+    }
+
+    @Test
+    fun testNoFiltersAndSchedulersRandom() {
+        val scheduler = FilterScheduler(
+            filters = emptyList(),
+            weighers = emptyList(),
+            subsetSize = Int.MAX_VALUE,
+            random = Random(1)
+        )
+
+        val hostA = mockk<HostView>()
+        every { hostA.host.state } returns HostState.DOWN
+
+        val hostB = mockk<HostView>()
+        every { hostB.host.state } returns HostState.UP
+
+        scheduler.addHost(hostA)
+        scheduler.addHost(hostB)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        // Make sure we get the first host both times
+        assertAll(
+            { assertEquals(hostB, scheduler.select(server)) },
+            { assertEquals(hostA, scheduler.select(server)) }
+        )
+    }
+
+    @Test
+    fun testHostIsDown() {
+        val scheduler = FilterScheduler(
+            filters = listOf(ComputeFilter()),
+            weighers = emptyList(),
+        )
+
+        val host = mockk<HostView>()
+        every { host.host.state } returns HostState.DOWN
+
+        scheduler.addHost(host)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        assertNull(scheduler.select(server))
+    }
+
+    @Test
+    fun testHostIsUp() {
+        val scheduler = FilterScheduler(
+            filters = listOf(ComputeFilter()),
+            weighers = emptyList(),
+        )
+
+        val host = mockk<HostView>()
+        every { host.host.state } returns HostState.UP
+
+        scheduler.addHost(host)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        assertEquals(host, scheduler.select(server))
+    }
+
+    @Test
+    fun testRamFilter() {
+        val scheduler = FilterScheduler(
+            filters = listOf(RamFilter(1.0)),
+            weighers = emptyList(),
+        )
+
+        val hostA = mockk<HostView>()
+        every { hostA.host.state } returns HostState.UP
+        every { hostA.host.model } returns HostModel(4, 2048)
+        every { hostA.availableMemory } returns 512
+
+        val hostB = mockk<HostView>()
+        every { hostB.host.state } returns HostState.UP
+        every { hostB.host.model } returns HostModel(4, 2048)
+        every { hostB.availableMemory } returns 2048
+
+        scheduler.addHost(hostA)
+        scheduler.addHost(hostB)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        assertEquals(hostB, scheduler.select(server))
+    }
+
+    @Test
+    fun testRamFilterOvercommit() {
+        val scheduler = FilterScheduler(
+            filters = listOf(RamFilter(1.5)),
+            weighers = emptyList(),
+        )
+
+        val host = mockk<HostView>()
+        every { host.host.state } returns HostState.UP
+        every { host.host.model } returns HostModel(4, 2048)
+        every { host.availableMemory } returns 2048
+
+        scheduler.addHost(host)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 2300
+
+        assertNull(scheduler.select(server))
+    }
+
+    @Test
+    fun testVCpuFilter() {
+        val scheduler = FilterScheduler(
+            filters = listOf(VCpuFilter(1.0)),
+            weighers = emptyList(),
+        )
+
+        val hostA = mockk<HostView>()
+        every { hostA.host.state } returns HostState.UP
+        every { hostA.host.model } returns HostModel(4, 2048)
+        every { hostA.provisionedCores } returns 3
+
+        val hostB = mockk<HostView>()
+        every { hostB.host.state } returns HostState.UP
+        every { hostB.host.model } returns HostModel(4, 2048)
+        every { hostB.provisionedCores } returns 0
+
+        scheduler.addHost(hostA)
+        scheduler.addHost(hostB)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        assertEquals(hostB, scheduler.select(server))
+    }
+
+    @Test
+    fun testVCpuFilterOvercommit() {
+        val scheduler = FilterScheduler(
+            filters = listOf(VCpuFilter(16.0)),
+            weighers = emptyList(),
+        )
+
+        val host = mockk<HostView>()
+        every { host.host.state } returns HostState.UP
+        every { host.host.model } returns HostModel(4, 2048)
+        every { host.provisionedCores } returns 0
+
+        scheduler.addHost(host)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 8
+        every { server.flavor.memorySize } returns 1024
+
+        assertNull(scheduler.select(server))
+    }
+
+    @Test
+    fun testInstanceCountFilter() {
+        val scheduler = FilterScheduler(
+            filters = listOf(InstanceCountFilter(limit = 2)),
+            weighers = emptyList(),
+        )
+
+        val hostA = mockk<HostView>()
+        every { hostA.host.state } returns HostState.UP
+        every { hostA.host.model } returns HostModel(4, 2048)
+        every { hostA.instanceCount } returns 2
+
+        val hostB = mockk<HostView>()
+        every { hostB.host.state } returns HostState.UP
+        every { hostB.host.model } returns HostModel(4, 2048)
+        every { hostB.instanceCount } returns 0
+
+        scheduler.addHost(hostA)
+        scheduler.addHost(hostB)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        assertEquals(hostB, scheduler.select(server))
+    }
+
+    @Test
+    fun testRamWeigher() {
+        val scheduler = FilterScheduler(
+            filters = emptyList(),
+            weighers = listOf(RamWeigher(1.5)),
+        )
+
+        val hostA = mockk<HostView>()
+        every { hostA.host.state } returns HostState.UP
+        every { hostA.host.model } returns HostModel(4, 2048)
+        every { hostA.availableMemory } returns 1024
+
+        val hostB = mockk<HostView>()
+        every { hostB.host.state } returns HostState.UP
+        every { hostB.host.model } returns HostModel(4, 2048)
+        every { hostB.availableMemory } returns 512
+
+        scheduler.addHost(hostA)
+        scheduler.addHost(hostB)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        assertEquals(hostA, scheduler.select(server))
+    }
+
+    @Test
+    fun testCoreRamWeigher() {
+        val scheduler = FilterScheduler(
+            filters = emptyList(),
+            weighers = listOf(CoreRamWeigher(1.5)),
+        )
+
+        val hostA = mockk<HostView>()
+        every { hostA.host.state } returns HostState.UP
+        every { hostA.host.model } returns HostModel(12, 2048)
+        every { hostA.availableMemory } returns 1024
+
+        val hostB = mockk<HostView>()
+        every { hostB.host.state } returns HostState.UP
+        every { hostB.host.model } returns HostModel(4, 2048)
+        every { hostB.availableMemory } returns 512
+
+        scheduler.addHost(hostA)
+        scheduler.addHost(hostB)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        assertEquals(hostB, scheduler.select(server))
+    }
+
+    @Test
+    fun testVCpuWeigher() {
+        val scheduler = FilterScheduler(
+            filters = emptyList(),
+            weighers = listOf(VCpuWeigher(16.0)),
+        )
+
+        val hostA = mockk<HostView>()
+        every { hostA.host.state } returns HostState.UP
+        every { hostA.host.model } returns HostModel(4, 2048)
+        every { hostA.provisionedCores } returns 2
+
+        val hostB = mockk<HostView>()
+        every { hostB.host.state } returns HostState.UP
+        every { hostB.host.model } returns HostModel(4, 2048)
+        every { hostB.provisionedCores } returns 0
+
+        scheduler.addHost(hostA)
+        scheduler.addHost(hostB)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        assertEquals(hostB, scheduler.select(server))
+    }
+
+    @Test
+    fun testInstanceCountWeigher() {
+        val scheduler = FilterScheduler(
+            filters = emptyList(),
+            weighers = listOf(InstanceCountWeigher(multiplier = -1.0)),
+        )
+
+        val hostA = mockk<HostView>()
+        every { hostA.host.state } returns HostState.UP
+        every { hostA.host.model } returns HostModel(4, 2048)
+        every { hostA.instanceCount } returns 2
+
+        val hostB = mockk<HostView>()
+        every { hostB.host.state } returns HostState.UP
+        every { hostB.host.model } returns HostModel(4, 2048)
+        every { hostB.instanceCount } returns 0
+
+        scheduler.addHost(hostA)
+        scheduler.addHost(hostB)
+
+        val server = mockk<Server>()
+        every { server.flavor.cpuCount } returns 2
+        every { server.flavor.memorySize } returns 1024
+
+        assertEquals(hostB, scheduler.select(server))
+    }
+}