merge: Restructure experiments and remove legacy harness (#82)

This pull request restructures the experiments present in the `opendc-experiments` directory 
and removes the legacy OpenDC Harness. Previously, the experiments were written against
the OpenDC Harness, which facilitates generation and execution of scenarios.

However, the OpenDC Harness does not integrate well into the web-based workflow of OpenDC,
where users should be able to submit scenarios in the web interface and automatically simulate
it in the cloud, since the harness relied on a special Kotlin DSL to specify experiments.

In future pull request, we'll attempt to introduce a similar approach for specifying and
running experiments as we have done for the Radice experiments, where the entire
experiment is described in a serializable (JSON/YAML) format.

## Implementation Notes :hammer_and_pick:

* Add helper tools for FaaS simulations
* Fix infinite loop due to invalid rounding
* Convert experiment into integration test 
* Add independent Capelin distribution 
* Remove OpenDC Harness modules
* Remove unnecessary dependencies 

## Breaking API Changes :warning:

* Removal of the OpenDC Harness modules. Instead, we now package each experiment individually. 
  We'll focus in the future on extracting common code from the Capelin and Radice experiments 
  so they can be re-used by other experiments as well.

5 files changed, 398 insertions, 0 deletions

diff --git a/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FaaSServiceHelper.kt b/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FaaSServiceHelper.kt
new file mode 100644
index 00000000..ede6ac54
--- /dev/null
+++ b/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FaaSServiceHelper.kt
@@ -0,0 +1,153 @@
+/*
+ * 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 kotlinx.coroutines.*
+import mu.KotlinLogging
+import org.opendc.faas.api.FaaSFunction
+import org.opendc.faas.service.FaaSService
+import org.opendc.faas.service.FunctionObject
+import org.opendc.faas.service.autoscaler.FunctionTerminationPolicy
+import org.opendc.faas.service.deployer.FunctionDeployer
+import org.opendc.faas.service.deployer.FunctionInstance
+import org.opendc.faas.service.deployer.FunctionInstanceListener
+import org.opendc.faas.service.router.RoutingPolicy
+import org.opendc.faas.simulator.SimFunctionDeployer
+import org.opendc.faas.simulator.delay.ColdStartModel
+import org.opendc.faas.simulator.delay.StochasticDelayInjector
+import org.opendc.faas.simulator.delay.ZeroDelayInjector
+import org.opendc.simulator.compute.model.MachineModel
+import java.time.Clock
+import java.util.*
+import kotlin.coroutines.CoroutineContext
+import kotlin.math.max
+
+/**
+ * Helper class to simulate FaaS-based workloads in OpenDC.
+ *
+ * @param context A [CoroutineContext] to run the simulation in.
+ * @param clock A [Clock] instance tracking simulation time.
+ * @param machineModel The [MachineModel] that models the physical machine on which the functions run.
+ * @param routingPolicy The routing policy to use.
+ * @param terminationPolicy The function termination policy to use.
+ * @param coldStartModel The cold start models to test.
+ * @param seed The seed of the simulation.
+ */
+public class FaaSServiceHelper(
+    private val context: CoroutineContext,
+    private val clock: Clock,
+    private val machineModel: MachineModel,
+    private val routingPolicy: RoutingPolicy,
+    private val terminationPolicy: FunctionTerminationPolicy,
+    private val coldStartModel: ColdStartModel? = null,
+) : AutoCloseable {
+    /**
+     * The scope of this helper.
+     */
+    private val scope = CoroutineScope(context + Job())
+
+    /**
+     * The logger for this class.
+     */
+    private val logger = KotlinLogging.logger {}
+
+    /**
+     * The simulated function deployer.
+     */
+    private val deployer = object : FunctionDeployer {
+        override fun deploy(function: FunctionObject, listener: FunctionInstanceListener): FunctionInstance {
+            val deployer = checkNotNull(_deployer)
+            return deployer.deploy(function, listener)
+        }
+    }
+    private var _deployer: SimFunctionDeployer? = null
+
+    /**
+     * The [FaaSService] created by the helper.
+     */
+    public val service: FaaSService = FaaSService(
+        context,
+        clock,
+        deployer,
+        routingPolicy,
+        terminationPolicy
+    )
+
+    /**
+     * Run a simulation of the [FaaSService] by replaying the workload trace given by [trace].
+     *
+     * @param trace The trace to simulate.
+     * @param seed The seed for the simulation.
+     * @param functions The functions that have been created by the runner.
+     */
+    public suspend fun run(trace: List<FunctionTrace>, seed: Long = 0, functions: MutableList<FaaSFunction>? = null) {
+        // Set up the simulated deployer
+        val delayInjector = if (coldStartModel != null)
+            StochasticDelayInjector(coldStartModel, Random(seed))
+        else
+            ZeroDelayInjector
+        val traceById = trace.associateBy { it.id }
+        _deployer = SimFunctionDeployer(clock, scope, machineModel, delayInjector) {
+            FunctionTraceWorkload(traceById.getValue(it.name))
+        }
+
+        val client = service.newClient()
+        try {
+            coroutineScope {
+                for (entry in trace) {
+                    launch {
+                        val function = client.newFunction(entry.id, entry.maxMemory.toLong())
+                        functions?.add(function)
+
+                        var offset = Long.MIN_VALUE
+
+                        for (sample in entry.samples) {
+                            if (sample.invocations == 0) {
+                                continue
+                            }
+
+                            if (offset < 0) {
+                                offset = sample.timestamp - clock.millis()
+                            }
+
+                            delay(max(0, (sample.timestamp - offset) - clock.millis()))
+
+                            logger.info { "Invoking function ${entry.id} ${sample.invocations} times [${sample.timestamp}]" }
+
+                            repeat(sample.invocations) {
+                                function.invoke()
+                            }
+                        }
+                    }
+                }
+            }
+        } finally {
+            client.close()
+        }
+    }
+
+    override fun close() {
+        service.close()
+        scope.cancel()
+    }
+}
diff --git a/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FunctionSample.kt b/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FunctionSample.kt
new file mode 100644
index 00000000..418f895d
--- /dev/null
+++ b/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FunctionSample.kt
@@ -0,0 +1,44 @@
+/*
+ * 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.faas.workload
+
+/**
+ * A sample of a single function.
+ *
+ * @param timestamp The timestamp of the function.
+ * @param duration The average execution time of the function.
+ * @param invocations The number of invocations.
+ * @param provisionedCpu The provisioned CPU for this function in MHz.
+ * @param provisionedMem The amount of memory provisioned for this function in MB.
+ * @param cpuUsage The actual CPU usage in MHz.
+ * @param memUsage The actual memory usage in MB.
+ */
+public data class FunctionSample(
+    val timestamp: Long,
+    val duration: Long,
+    val invocations: Int,
+    val provisionedCpu: Int,
+    val provisionedMem: Int,
+    val cpuUsage: Double,
+    val memUsage: Double
+)
diff --git a/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FunctionTrace.kt b/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FunctionTrace.kt
new file mode 100644
index 00000000..712267e5
--- /dev/null
+++ b/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FunctionTrace.kt
@@ -0,0 +1,28 @@
+/*
+ * 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
+
+/**
+ * A trace for a single function
+ */
+public data class FunctionTrace(val id: String, val maxMemory: Int, val samples: List<FunctionSample>)
diff --git a/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FunctionTraceWorkload.kt b/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FunctionTraceWorkload.kt
new file mode 100644
index 00000000..cdb800c3
--- /dev/null
+++ b/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/FunctionTraceWorkload.kt
@@ -0,0 +1,37 @@
+/*
+ * 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.opendc.faas.simulator.workload.SimFaaSWorkload
+import org.opendc.simulator.compute.workload.SimTrace
+import org.opendc.simulator.compute.workload.SimTraceFragment
+import org.opendc.simulator.compute.workload.SimTraceWorkload
+import org.opendc.simulator.compute.workload.SimWorkload
+
+/**
+ * A [SimFaaSWorkload] for a [FunctionTrace].
+ */
+public class FunctionTraceWorkload(trace: FunctionTrace) :
+    SimFaaSWorkload, SimWorkload by SimTraceWorkload(SimTrace.ofFragments(trace.samples.map { SimTraceFragment(it.timestamp, it.duration, it.cpuUsage, 1) })) {
+    override suspend fun invoke() {}
+}
diff --git a/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/ServerlessTraceReader.kt b/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/ServerlessTraceReader.kt
new file mode 100644
index 00000000..3694cf30
--- /dev/null
+++ b/opendc-faas/opendc-faas-workload/src/main/kotlin/org/opendc/faas/workload/ServerlessTraceReader.kt
@@ -0,0 +1,136 @@
+/*
+ * 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 com.fasterxml.jackson.core.JsonToken
+import com.fasterxml.jackson.dataformat.csv.CsvFactory
+import com.fasterxml.jackson.dataformat.csv.CsvParser
+import com.fasterxml.jackson.dataformat.csv.CsvSchema
+import mu.KotlinLogging
+import java.io.File
+import kotlin.math.max
+
+/**
+ * A trace reader for the serverless workload trace used in the OpenDC Serverless thesis.
+ */
+public class ServerlessTraceReader {
+    /**
+     * The logger for this trace reader instance.
+     */
+    private val logger = KotlinLogging.logger {}
+
+    /**
+     * The [CsvFactory] used to create the parser.
+     */
+    private val factory = CsvFactory()
+        .enable(CsvParser.Feature.ALLOW_COMMENTS)
+        .enable(CsvParser.Feature.TRIM_SPACES)
+
+    /**
+     * Parse the traces at the specified [path].
+     */
+    public fun parse(path: File): List<FunctionTrace> {
+        return if (path.isFile) {
+            listOf(parseSingle(path))
+        } else {
+            path.walk()
+                .filterNot { it.isDirectory }
+                .sorted()
+                .map { file ->
+                    logger.info { "Parsing $file" }
+                    parseSingle(file)
+                }
+                .toList()
+        }
+    }
+
+    /**
+     * Parse a single trace.
+     */
+    private fun parseSingle(path: File): FunctionTrace {
+        val samples = mutableListOf<FunctionSample>()
+
+        val parser = factory.createParser(path)
+        parser.schema = schema
+
+        var id = ""
+        var timestamp = 0L
+        var invocations = 0
+        var execTime = 0L
+        var provisionedCpu = 0
+        var provisionedMem = 0
+        var cpuUsage = 0.0
+        var memUsage = 0.0
+        var maxMemory = 0
+
+        while (!parser.isClosed) {
+            val token = parser.nextValue()
+            if (token == JsonToken.END_OBJECT) {
+                maxMemory = max(maxMemory, provisionedMem)
+                samples.add(FunctionSample(timestamp, execTime, invocations, provisionedCpu, provisionedMem, cpuUsage, memUsage))
+
+                id = ""
+                timestamp = 0
+                invocations = 0
+                execTime = 0
+                provisionedCpu = 0
+                provisionedMem = 0
+                cpuUsage = 0.0
+                memUsage = 0.0
+
+                continue
+            }
+
+            when (parser.currentName) {
+                "Timestamp [ms]" -> timestamp = parser.valueAsLong
+                "Invocations" -> invocations = parser.valueAsInt
+                "Avg Exec time per Invocation" -> execTime = parser.valueAsLong
+                "Provisioned CPU [Mhz]" -> provisionedCpu = parser.valueAsInt
+                "Provisioned Memory [mb]" -> provisionedMem = parser.valueAsInt
+                "Avg cpu usage per Invocation [Mhz]" -> cpuUsage = parser.valueAsDouble
+                "Avg mem usage per Invocation [mb]" -> memUsage = parser.valueAsDouble
+                "name" -> id = parser.text
+            }
+        }
+
+        return FunctionTrace(id, maxMemory, samples)
+    }
+
+    private companion object {
+        /**
+         * The [CsvSchema] that is used to parse the trace.
+         */
+        val schema = CsvSchema.builder()
+            .addColumn("Timestamp [ms]", CsvSchema.ColumnType.NUMBER)
+            .addColumn("Invocations", CsvSchema.ColumnType.NUMBER)
+            .addColumn("Avg Exec time per Invocation", CsvSchema.ColumnType.NUMBER)
+            .addColumn("Provisioned CPU [Mhz]", CsvSchema.ColumnType.NUMBER)
+            .addColumn("Provisioned Memory [mb]", CsvSchema.ColumnType.NUMBER)
+            .addColumn("Avg cpu usage per Invocation [Mhz]", CsvSchema.ColumnType.NUMBER)
+            .addColumn("Avg mem usage per Invocation [mb]", CsvSchema.ColumnType.NUMBER)
+            .addColumn("name", CsvSchema.ColumnType.STRING)
+            .setAllowComments(true)
+            .setUseHeader(true)
+            .build()
+    }
+}