markusthoemmes commented on a change in pull request #2282: Distributed tracing support #2192 URL: https://github.com/apache/incubator-openwhisk/pull/2282#discussion_r126937707
########## File path: common/scala/src/main/scala/whisk/common/tracing/TraceUtil.scala ########## @@ -0,0 +1,141 @@ +/* + * Copyright 2015-2016 IBM Corporation + * + * Licensed 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.common.tracing + +import java.util.concurrent.atomic.AtomicInteger +import scala.collection.mutable.Map +import akka.actor.ActorSystem +import com.github.levkhomich.akka.tracing._ +import whisk.common.{LoggingMarkers, TransactionId} + +/** + * Trace Utility Class which provides all methods to trace a given service. + */ +object TraceUtil{ + + private lazy val trace: TracingExtensionImpl = traceVar; + + private var traceVar: TracingExtensionImpl = null; + + private val traceMap : Map[Long, TracedRequest] = Map[Long, TracedRequest]() + + var requestCounter: AtomicInteger = new AtomicInteger(1); + + def init (actorSystem: ActorSystem): TracingExtensionImpl = { + + if(traceVar == null) + traceVar = TracingExtension.apply(actorSystem); + + return trace; + } + + /** + * Start a Trace for given service. + * @param serviceName Name of Service to be traced + * @param transactionId transactionId to which this Trace belongs. + * @return TracedRequest which provides details about current service being traced. + */ + def startTrace(serviceName: String, spanName: String, transactionId: TransactionId): Unit = { + traceMap.get(transactionId.meta.id) match { + case Some(tracedRequest) => { + startChildTrace(serviceName, spanName, tracedRequest, transactionId) + } + case None => { + var tracedRequest = createTracedRequest(spanName) + var metadata = trace.sample(tracedRequest.request, serviceName) + if (metadata != None) { + trace.start(tracedRequest.request, serviceName) + tracedRequest = new TracedRequest(tracedRequest.request, null, metadata) + traceMap.put(transactionId.meta.id, tracedRequest) + } + } + } + + } + + /** + * Start a Child Trace + * @param serviceName Name of service to be traced + * @param parent Parent TracedRequest to continue span propagation and create span hierarchy. + * @param transactionId transactionId to which this Trace belongs. + * @return TracedRequest which provides details about current service being traced. + */ + def startChildTrace(serviceName: String, spanName: String, parent: TracedRequest, transactionId: TransactionId): Unit = { + val tracedReq: TracedRequest = createTracedRequest(spanName) + var metadata = trace.sample(tracedReq.request, serviceName) + if(metadata.isDefined){ + trace.createChild(tracedReq.request, parent.request) + trace.start(tracedReq.request, serviceName) + val tracedRequest = new TracedRequest(tracedReq.request, Some(parent), metadata) + traceMap.put(transactionId.meta.id, tracedRequest) + } + } + + /** + * Finish a Trace associated with given transactionId. + * @param transactionId + */ + def finish(transactionId: TransactionId): Unit = { + traceMap.get(transactionId.meta.id) match { + case Some(tracedRequest) => { + trace.record(tracedRequest.request, TracingAnnotations.ServerSend) + traceMap.remove(transactionId.meta.id) + if(tracedRequest.parent.isDefined) + traceMap.put(transactionId.meta.id, tracedRequest.parent.get) + } + case _ => + } + } + + def error(transactionId: TransactionId, t: Throwable) : Unit = { + val tracedRequest = traceMap.get(transactionId.meta.id) + if(tracedRequest.isDefined){ + trace.record(tracedRequest.get.request, t) + } + } + + private def createTracedRequest(spanName: String, metadata: Option[SpanMetadata] = None) : TracedRequest = { + val headers: Map[String, Integer] = Map[String, Integer]() + headers.put("id", requestCounter.getAndIncrement()) + val req: BasicTraceRequest = new BasicTraceRequest(headers, spanName) + + if(metadata.isDefined) + trace.importMetadata(req, metadata.get, spanName) Review comment: While the `isDefined/get` combi works and is safe, it requires the human to check that the `if` is in place. By using Option's combinators, we can get a more bulletproof line: ``` metadata.foreach(data => trace.importMetadata(req, data, spanName)) ``` ---------------------------------------------------------------- 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
