perf(compute): Redesign VM interference algorithm

This change redesigns the virtual machine interference algorithm to have
a fixed memory usage per `VmInterferenceModel` instance. Previously, for
every interference domain, a copy of the model would be created, leading
to OutOfMemory errors when running multiple experiments at the same
time.

3 files changed, 133 insertions, 81 deletions

diff --git a/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/util/PerformanceInterferenceReader.kt b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/util/PerformanceInterferenceReader.kt
deleted file mode 100644
index 67f9626c..00000000
--- a/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/util/PerformanceInterferenceReader.kt
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * 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.workload.util
-
-import com.fasterxml.jackson.annotation.JsonProperty
-import com.fasterxml.jackson.databind.ObjectMapper
-import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
-import com.fasterxml.jackson.module.kotlin.readValue
-import org.opendc.simulator.compute.kernel.interference.VmInterferenceGroup
-import java.io.File
-import java.io.InputStream
-
-/**
- * A parser for the JSON performance interference setup files used for the TPDS article on Capelin.
- */
-public class PerformanceInterferenceReader {
-    /**
-     * The [ObjectMapper] to use.
-     */
-    private val mapper = jacksonObjectMapper()
-
-    init {
-        mapper.addMixIn(VmInterferenceGroup::class.java, GroupMixin::class.java)
-    }
-
-    /**
-     * Read the performance interface model from [file].
-     */
-    public fun read(file: File): List<VmInterferenceGroup> {
-        return mapper.readValue(file)
-    }
-
-    /**
-     * Read the performance interface model from the input.
-     */
-    public fun read(input: InputStream): List<VmInterferenceGroup> {
-        return mapper.readValue(input)
-    }
-
-    private data class GroupMixin(
-        @JsonProperty("minServerLoad")
-        val targetLoad: Double,
-        @JsonProperty("performanceScore")
-        val score: Double,
-        @JsonProperty("vms")
-        val members: Set<String>,
-    )
-}
diff --git a/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/util/VmInterferenceModelReader.kt b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/util/VmInterferenceModelReader.kt
new file mode 100644
index 00000000..e0fa8904
--- /dev/null
+++ b/opendc-compute/opendc-compute-workload/src/main/kotlin/org/opendc/compute/workload/util/VmInterferenceModelReader.kt
@@ -0,0 +1,128 @@
+/*
+ * 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.workload.util
+
+import com.fasterxml.jackson.annotation.JsonProperty
+import com.fasterxml.jackson.core.JsonParseException
+import com.fasterxml.jackson.core.JsonParser
+import com.fasterxml.jackson.core.JsonToken
+import com.fasterxml.jackson.databind.ObjectMapper
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import org.opendc.simulator.compute.kernel.interference.VmInterferenceModel
+import java.io.File
+import java.io.InputStream
+
+/**
+ * A parser for the JSON performance interference setup files used for the TPDS article on Capelin.
+ */
+public class VmInterferenceModelReader {
+    /**
+     * The [ObjectMapper] to use.
+     */
+    private val mapper = jacksonObjectMapper()
+
+    /**
+     * Read the performance interface model from [file].
+     */
+    public fun read(file: File): VmInterferenceModel {
+        val builder = VmInterferenceModel.builder()
+        val parser = mapper.createParser(file)
+        parseGroups(parser, builder)
+        return builder.build()
+    }
+
+    /**
+     * Read the performance interface model from the input.
+     */
+    public fun read(input: InputStream): VmInterferenceModel {
+        val builder = VmInterferenceModel.builder()
+        val parser = mapper.createParser(input)
+        parseGroups(parser, builder)
+        return builder.build()
+    }
+
+    /**
+     * Parse all groups in an interference JSON file.
+     */
+    private fun parseGroups(parser: JsonParser, builder: VmInterferenceModel.Builder) {
+        parser.nextToken()
+
+        if (!parser.isExpectedStartArrayToken) {
+            throw JsonParseException(parser, "Expected array at start, but got ${parser.currentToken()}")
+        }
+
+        while (parser.nextToken() != JsonToken.END_ARRAY) {
+            parseGroup(parser, builder)
+        }
+    }
+
+    /**
+     * Parse a group an interference JSON file.
+     */
+    private fun parseGroup(parser: JsonParser, builder: VmInterferenceModel.Builder) {
+        var targetLoad = Double.POSITIVE_INFINITY
+        var score = 1.0
+        val members = mutableSetOf<String>()
+
+        if (!parser.isExpectedStartObjectToken) {
+            throw JsonParseException(parser, "Expected object, but got ${parser.currentToken()}")
+        }
+
+        while (parser.nextValue() != JsonToken.END_OBJECT) {
+            when (parser.currentName) {
+                "vms" -> parseGroupMembers(parser, members)
+                "minServerLoad" -> targetLoad = parser.doubleValue
+                "performanceScore" -> score = parser.doubleValue
+            }
+        }
+
+        builder.addGroup(members, targetLoad, score)
+    }
+
+    /**
+     * Parse the members of a group.
+     */
+    private fun parseGroupMembers(parser: JsonParser, members: MutableSet<String>) {
+        if (!parser.isExpectedStartArrayToken) {
+            throw JsonParseException(parser, "Expected array for group members, but got ${parser.currentToken()}")
+        }
+
+        while (parser.nextValue() != JsonToken.END_ARRAY) {
+            if (parser.currentToken() != JsonToken.VALUE_STRING) {
+                throw JsonParseException(parser, "Expected string value for group member")
+            }
+
+            val member = parser.text.removePrefix("vm__workload__").removeSuffix(".txt")
+            members.add(member)
+        }
+    }
+
+    private data class Group(
+        @JsonProperty("minServerLoad")
+        val targetLoad: Double,
+        @JsonProperty("performanceScore")
+        val score: Double,
+        @JsonProperty("vms")
+        val members: Set<String>,
+    )
+}
diff --git a/opendc-compute/opendc-compute-workload/src/test/kotlin/org/opendc/compute/workload/util/PerformanceInterferenceReaderTest.kt b/opendc-compute/opendc-compute-workload/src/test/kotlin/org/opendc/compute/workload/util/VmInterferenceModelReaderTest.kt
index c79f0584..1c3e7149 100644
--- a/opendc-compute/opendc-compute-workload/src/test/kotlin/org/opendc/compute/workload/util/PerformanceInterferenceReaderTest.kt
+++ b/opendc-compute/opendc-compute-workload/src/test/kotlin/org/opendc/compute/workload/util/VmInterferenceModelReaderTest.kt
@@ -22,24 +22,16 @@
 
 package org.opendc.compute.workload.util
 
-import org.junit.jupiter.api.Assertions.assertEquals
 import org.junit.jupiter.api.Test
-import org.junit.jupiter.api.assertAll
+import org.junit.jupiter.api.assertDoesNotThrow
 
 /**
- * Test suite for the [PerformanceInterferenceReader] class.
+ * Test suite for the [VmInterferenceModelReader] class.
  */
-class PerformanceInterferenceReaderTest {
+class VmInterferenceModelReaderTest {
     @Test
     fun testSmoke() {
-        val input = checkNotNull(PerformanceInterferenceReader::class.java.getResourceAsStream("/perf-interference.json"))
-        val result = PerformanceInterferenceReader().read(input)
-
-        assertAll(
-            { assertEquals(2, result.size) },
-            { assertEquals(setOf("vm_a", "vm_c", "vm_x", "vm_y"), result[0].members) },
-            { assertEquals(0.0, result[0].targetLoad, 0.001) },
-            { assertEquals(0.8830158730158756, result[0].score, 0.001) }
-        )
+        val input = checkNotNull(VmInterferenceModelReader::class.java.getResourceAsStream("/perf-interference.json"))
+        assertDoesNotThrow { VmInterferenceModelReader().read(input) }
     }
 }