feat(faas): Add helper tools for FaaS simulations

This change adds a new module, opendc-faas-workload that contains
helper code for constructing simulations of FaaS-based workloads
using OpenDC. In addition, we add an integration test that demonstrates
the capabilities of the helper tool and the FaaS platform of OpenDC.

2 files changed, 129 insertions, 0 deletions

diff --git a/opendc-faas/opendc-faas-workload/src/test/kotlin/org/opendc/faas/workload/FaaSServiceHelperTest.kt b/opendc-faas/opendc-faas-workload/src/test/kotlin/org/opendc/faas/workload/FaaSServiceHelperTest.kt
new file mode 100644
index 00000000..dbe024c0
--- /dev/null
+++ b/opendc-faas/opendc-faas-workload/src/test/kotlin/org/opendc/faas/workload/FaaSServiceHelperTest.kt
@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2022 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.faas.workload
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertAll
+import org.opendc.faas.service.autoscaler.FunctionTerminationPolicyFixed
+import org.opendc.faas.service.router.RandomRoutingPolicy
+import org.opendc.faas.simulator.delay.ColdStartModel
+import org.opendc.simulator.compute.model.MachineModel
+import org.opendc.simulator.compute.model.MemoryUnit
+import org.opendc.simulator.compute.model.ProcessingNode
+import org.opendc.simulator.compute.model.ProcessingUnit
+import org.opendc.simulator.core.runBlockingSimulation
+import java.io.File
+import java.time.Duration
+
+/**
+ * Integration test suite for the [FaaSServiceHelper] class.
+ */
+class FaaSServiceHelperTest {
+    /**
+     * Smoke test that simulates a small trace.
+     */
+    @Test
+    fun testSmoke() = runBlockingSimulation {
+        val trace = ServerlessTraceReader().parse(File("src/test/resources/trace"))
+        val runner = FaaSServiceHelper(
+            coroutineContext,
+            clock,
+            createMachineModel(),
+            RandomRoutingPolicy(),
+            FunctionTerminationPolicyFixed(coroutineContext, clock, timeout = Duration.ofMinutes(10)),
+            coldStartModel = ColdStartModel.GOOGLE
+        )
+
+        try {
+            runner.run(trace)
+        } finally {
+            runner.close()
+        }
+
+        val stats = runner.service.getSchedulerStats()
+
+        assertAll(
+            { assertEquals(14, stats.totalInvocations) },
+            { assertEquals(2, stats.timelyInvocations) },
+            { assertEquals(12, stats.delayedInvocations) },
+        )
+    }
+
+    /**
+     * Construct the machine model to test with.
+     */
+    private fun createMachineModel(): MachineModel {
+        val cpuNode = ProcessingNode("Intel", "Xeon", "amd64", 2)
+
+        return MachineModel(
+            cpus = List(cpuNode.coreCount) { ProcessingUnit(cpuNode, it, 1000.0) },
+            memory = List(4) { MemoryUnit("Crucial", "MTA18ASF4G72AZ-3G2B1", 3200.0, 32_000) }
+        )
+    }
+}
diff --git a/opendc-faas/opendc-faas-workload/src/test/kotlin/org/opendc/faas/workload/ServerlessTraceReaderTest.kt b/opendc-faas/opendc-faas-workload/src/test/kotlin/org/opendc/faas/workload/ServerlessTraceReaderTest.kt
new file mode 100644
index 00000000..e835d4d9
--- /dev/null
+++ b/opendc-faas/opendc-faas-workload/src/test/kotlin/org/opendc/faas/workload/ServerlessTraceReaderTest.kt
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2022 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.faas.workload
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.assertAll
+import java.io.File
+
+/**
+ * Test suite for [ServerlessTraceReader].
+ */
+class ServerlessTraceReaderTest {
+    @Test
+    fun testSmoke() {
+        val path = File("src/test/resources/trace")
+        val trace = ServerlessTraceReader().parse(path)
+
+        assertAll(
+            { assertEquals(2, trace.size) },
+            { assertEquals("004c1ea5eb15978682b00ab659aed21e2835d5287668da8d5267f751fdfbdd78", trace[0].id) },
+            { assertEquals(256, trace[0].maxMemory) }
+        )
+    }
+}