markusthoemmes commented on a change in pull request #3886: Proposing Lean OpenWhisk URL: https://github.com/apache/incubator-openwhisk/pull/3886#discussion_r206266383
########## File path: core/lean/src/main/scala/whisk/core/loadBalancer/LeanBalancer.scala ########## @@ -0,0 +1,256 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package whisk.core.loadBalancer + +import java.nio.charset.StandardCharsets +import java.util.concurrent.atomic.LongAdder + +import akka.actor.{ActorSystem, Props} +import akka.event.Logging.InfoLevel +import akka.stream.ActorMaterializer +import org.apache.kafka.clients.producer.RecordMetadata +import pureconfig._ +import whisk.spi.SpiLoader +import whisk.core.entity._ +import whisk.core.entity.size._ +import whisk.common.LoggingMarkers._ +import whisk.common._ +import whisk.core.WhiskConfig._ +import whisk.core.connector._ +import whisk.core.WhiskConfig +import whisk.core.ConfigKeys +import scala.collection.concurrent.TrieMap +import scala.concurrent.duration._ +import scala.concurrent.{ExecutionContext, Future, Promise} +import scala.util.{Failure, Success} +import whisk.core.invoker.InvokerReactive +import whisk.utils.ExecutionContextFactory + +/** + * A loadbalancer that uses "horizontal" sharding to not collide with fellow loadbalancers. + * + * Horizontal sharding means, that each invoker's capacity is evenly divided between the loadbalancers. If an invoker + * has at most 16 slots available, those will be divided to 8 slots for each loadbalancer (if there are 2). + */ +class LeanBalancer(config: WhiskConfig, controllerInstance: ControllerInstanceId)(implicit val actorSystem: ActorSystem, + logging: Logging, + materializer: ActorMaterializer) + extends LoadBalancer { + + private implicit val executionContext: ExecutionContext = actorSystem.dispatcher + + private val lbConfig = loadConfigOrThrow[ShardingContainerPoolBalancerConfig](ConfigKeys.loadbalancer) + + /** State related to invocations and throttling */ + private val activations = TrieMap[ActivationId, ActivationEntry]() + private val activationsPerNamespace = TrieMap[UUID, LongAdder]() + private val totalActivations = new LongAdder() + private val totalActivationMemory = new LongAdder() + + /** State needed for scheduling. */ + private val schedulingState = ShardingContainerPoolBalancerState()() + + actorSystem.scheduler.schedule(0.seconds, 10.seconds) { + MetricEmitter.emitHistogramMetric(LOADBALANCER_ACTIVATIONS_INFLIGHT(controllerInstance), totalActivations.longValue) + MetricEmitter.emitHistogramMetric(LOADBALANCER_MEMORY_INFLIGHT(controllerInstance), totalActivationMemory.longValue) + } + + /** Loadbalancer interface methods */ + override def invokerHealth(): Future[IndexedSeq[InvokerHealth]] = Future.successful(IndexedSeq.empty[InvokerHealth]) + override def activeActivationsFor(namespace: UUID): Future[Int] = + Future.successful(activationsPerNamespace.get(namespace).map(_.intValue()).getOrElse(0)) + override def totalActiveActivations: Future[Int] = Future.successful(totalActivations.intValue()) + override def clusterSize: Int = 1 + + val invokerName = InvokerInstanceId(0) + val controllerName = ControllerInstanceId("controller-lean") + + /** 1. Publish a message to the loadbalancer */ + override def publish(action: ExecutableWhiskActionMetaData, msg: ActivationMessage)( + implicit transid: TransactionId): Future[Future[Either[ActivationId, WhiskActivation]]] = { + logging.info(this, "in LeanBalancer.publish") + val entry = setupActivation(msg, action, invokerName) + sendActivationToInvoker(messageProducer, msg, invokerName).map { _ => + entry.promise.future + } + } + + /** 2. Update local state with the to be executed activation */ + private def setupActivation(msg: ActivationMessage, + action: ExecutableWhiskActionMetaData, + instance: InvokerInstanceId): ActivationEntry = { + + totalActivations.increment() + totalActivationMemory.add(action.limits.memory.megabytes) + activationsPerNamespace.getOrElseUpdate(msg.user.namespace.uuid, new LongAdder()).increment() + val timeout = (action.limits.timeout.duration.max(TimeLimit.STD_DURATION) * lbConfig.timeoutFactor) + 1.minute + // Install a timeout handler for the catastrophic case where an active ack is not received at all + // (because say an invoker is down completely, or the connection to the message bus is disrupted) or when + // the active ack is significantly delayed (possibly dues to long queues but the subject should not be penalized); + // in this case, if the activation handler is still registered, remove it and update the books. + activations.getOrElseUpdate( + msg.activationId, { + val timeoutHandler = actorSystem.scheduler.scheduleOnce(timeout) { + processCompletion(Left(msg.activationId), msg.transid, forced = true, invoker = instance) + } + + // please note: timeoutHandler.cancel must be called on all non-timeout paths, e.g. Success + ActivationEntry( + msg.activationId, + msg.user.namespace.uuid, + instance, + action.limits.memory.megabytes.MB, + timeoutHandler, + Promise[Either[ActivationId, WhiskActivation]]()) + }) + } + + private val messagingProvider = SpiLoader.get[MessagingProvider] + private val messageProducer = messagingProvider.getProducer(config) + + /** 3. Send the activation to the invoker */ + private def sendActivationToInvoker(producer: MessageProducer, + msg: ActivationMessage, + invoker: InvokerInstanceId): Future[RecordMetadata] = { + implicit val transid: TransactionId = msg.transid + logging.info(this, "in LeanBalancer.sendActivationToInvoker") + + val topic = s"invoker${invoker.toInt}" + + MetricEmitter.emitCounterMetric(LoggingMarkers.LOADBALANCER_ACTIVATION_START) + val start = transid.started( + this, + LoggingMarkers.CONTROLLER_KAFKA, + s"posting topic '$topic' with activation id '${msg.activationId}'", + logLevel = InfoLevel) + + logging.info(this, "before producer.send") + producer.send(topic, msg).andThen { + case Success(status) => + logging.info(this, "producer.send finished with Success") + transid.finished(this, start, s"posted to $topic", logLevel = InfoLevel) + case Failure(_) => + logging.info(this, "producer.send finished with Failure") + transid.failed(this, start, s"error on posting to topic $topic") + } + } + + /** + * Subscribes to active acks (completion messages from the invokers), and + * registers a handler for received active acks from invokers. + */ + private val activeAckTopic = s"completed${controllerInstance.asString}" + private val maxActiveAcksPerPoll = 128 + private val activeAckPollDuration = 1.second + private val activeAckConsumer = + messagingProvider.getConsumer(config, activeAckTopic, activeAckTopic, maxPeek = maxActiveAcksPerPoll) + + private val activationFeed = actorSystem.actorOf(Props { + new MessageFeed( + "activeack", + logging, + activeAckConsumer, + maxActiveAcksPerPoll, + activeAckPollDuration, + processActiveAck) + }) + + /** 4. Get the active-ack message and parse it */ + private def processActiveAck(bytes: Array[Byte]): Future[Unit] = Future { + val raw = new String(bytes, StandardCharsets.UTF_8) + CompletionMessage.parse(raw) match { + case Success(m: CompletionMessage) => + processCompletion(m.response, m.transid, forced = false, invoker = m.invoker) + activationFeed ! MessageFeed.Processed + + case Failure(t) => + activationFeed ! MessageFeed.Processed + logging.error(this, s"failed processing message: $raw with $t") + } + } + + /** 5. Process the active-ack and update the state accordingly */ + private def processCompletion(response: Either[ActivationId, WhiskActivation], + tid: TransactionId, + forced: Boolean, + invoker: InvokerInstanceId): Unit = { + val aid = response.fold(l => l, r => r.activationId) + + // treat left as success (as it is the result of a message exceeding the bus limit) + val isSuccess = response.fold(_ => true, r => !r.response.isWhiskError) + logging.info(this, "in processCompletion, aid: " + aid) + logging.info( + this, + "totalActivations: " + totalActivations + .toString() + " ctivationsPerNamespace.get(entry.namespaceId): " + activationsPerNamespace.toString()) + + activations.remove(aid) match { + case Some(entry) => + logging.info(this, "in processCompletion Some!!!") + totalActivations.decrement() + activationsPerNamespace.get(entry.namespaceId).foreach(_.decrement()) +// schedulingState.invokerSlots.lift(invoker.toInt).foreach(_.release()) + + if (!forced) { + entry.timeoutHandler.cancel() + entry.promise.trySuccess(response) + } else { + entry.promise.tryFailure(new Throwable("no active ack received")) + } + + logging.info(this, s"${if (!forced) "received" else "forced"} active ack for '$aid'")(tid) + // Active acks that are received here are strictly from user actions - health actions are not part of + // the load balancer's activation map. Inform the invoker pool supervisor of the user action completion. +// invokerPool ! InvocationFinishedMessage(invoker, isSuccess) + case None if !forced => + // the entry has already been removed but we receive an active ack for this activation Id. + // This happens for health actions, because they don't have an entry in Loadbalancerdata or + // for activations that already timed out. +// invokerPool ! InvocationFinishedMessage(invoker, isSuccess) + logging.info(this, "in processCompletion None1") + logging.info(this, s"received active ack for '$aid' which has no entry")(tid) + case None => + // the entry has already been removed by an active ack. This part of the code is reached by the timeout. + // As the active ack is already processed we don't have to do anything here. + logging.info(this, "in processCompletion None2") Review comment: Please remove the debug logging or move it to debug if really needed. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
