Github user revans2 commented on a diff in the pull request:
https://github.com/apache/storm/pull/2319#discussion_r138662036
--- Diff:
storm-core/src/jvm/org/apache/storm/assignments/AssignmentDistributionService.java
---
@@ -0,0 +1,232 @@
+/**
+ * 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
+ * <p/>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p/>
+ * 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 org.apache.storm.assignments;
+
+import org.apache.storm.Config;
+import org.apache.storm.generated.SupervisorAssignments;
+import org.apache.storm.utils.SupervisorClient;
+import org.apache.storm.utils.Utils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Random;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * <p>A service for distributing master assignments to supervisors, this
service makes the assignments notification asynchronous.
+ * <p>We support multiple working threads to distribute assignment, every
thread has a queue buffer.
+ * <p>Master will shuffle its node request to the queues, if the target
queue is full, we just discard the request, let the supervisors sync instead.
+ * <p/>
+ * <pre>{@code
+ * Working mode
+ * +--------+ +-----------------+
+ * | queue1 | ==> | Working thread1 |
+ * +--------+ shuffle +--------+ +-----------------+
+ * | Master | ==>
+ * +--------+ +--------+ +-----------------+
+ * | queue2 | ==> | Working thread2 |
+ * +--------+ +-----------------+
+ * }
+ * </pre>
+ */
+public class AssignmentDistributionService implements Closeable {
+ private static final Logger LOG =
LoggerFactory.getLogger(AssignmentDistributionService.class);
+ private ExecutorService service;
+
+ /**
+ * Flag to indicate if the service is active
+ */
+ private volatile boolean active = false;
+
+ private Random random;
+ /**
+ * Working threads num.
+ */
+ private int threadsNum = 0;
+ /**
+ * Working thread queue size.
+ */
+ private int queueSize = 0;
+
+ /**
+ * Assignments request queue.
+ */
+ private volatile Map<Integer, LinkedBlockingQueue<NodeAssignments>>
assignmentsQueue;
+
+ private Map conf;
+
+ /**
+ * Function for initialization.
+ *
+ * @param conf
+ */
+ public void prepare(Map conf) {
+ this.conf = conf;
+ this.random = new Random(47);
+
+ this.threadsNum =
Utils.getInt(conf.get(Config.NIMBUS_ASSIGNMENTS_SERVICE_THREADS), 10);
+ this.queueSize =
Utils.getInt(conf.get(Config.NIMBUS_ASSIGNMENTS_SERVICE_THREAD_QUEUE_SIZE),
100);
+
+ this.assignmentsQueue = new HashMap<>();
+ for (int i = 0; i < threadsNum; i++) {
+ this.assignmentsQueue.put(i, new
LinkedBlockingQueue<NodeAssignments>(queueSize));
+ }
+ //start the thread pool
+ this.service = Executors.newFixedThreadPool(threadsNum);
+ this.active = true;
+ //start the threads
+ for (int i = 0; i < threadsNum; i++) {
+ this.service.submit(new DistributeTask(this, i));
+ }
+ }
+
+ @Override
+ public void close() throws IOException {
+ this.active = false;
+ this.service.shutdownNow();
+ try {
+ this.service.awaitTermination(10l, TimeUnit.SECONDS);
+ } catch (InterruptedException e) {
+ LOG.error("Failed to close assignments distribute service");
+ }
+ this.assignmentsQueue = null;
+ }
+
+ public void addAssignmentsForNode(String node, SupervisorAssignments
assignments) {
+ try {
+ boolean success =
nextQueue().offer(NodeAssignments.getInstance(node, assignments), 5l,
TimeUnit.SECONDS);
+ if (!success) {
+ LOG.warn("Discard an assignment distribution for node {}
because the target sub queue is full", node);
+ }
+
+ } catch (InterruptedException e) {
+ LOG.error("Add node assignments interrupted: {}",
e.getMessage());
+ throw new RuntimeException(e);
+ }
+ }
+
+ static class NodeAssignments {
+ private String node;
+ private SupervisorAssignments assignments;
+
+ private NodeAssignments(String node, SupervisorAssignments
assignments) {
+ this.node = node;
+ this.assignments = assignments;
+ }
+
+ public static NodeAssignments getInstance(String node,
SupervisorAssignments assignments) {
+ return new NodeAssignments(node, assignments);
+ }
+
+ public String getNode() {
+ return this.node;
+ }
+
+ public SupervisorAssignments getAssignments() {
+ return this.assignments;
+ }
+
+ }
+
+ /**
+ * Task to distribute assignments.
+ */
+ static class DistributeTask implements Runnable {
+ private AssignmentDistributionService service;
+ private Integer queueIndex;
+
+ DistributeTask(AssignmentDistributionService service, Integer
index) {
+ this.service = service;
+ this.queueIndex = index;
+ }
+
+ @Override
+ public void run() {
+ while (true) {
+ try {
+ NodeAssignments nodeAssignments =
this.service.nextAssignments(queueIndex);
+ sendAssignmentsToNode(nodeAssignments);
+ } catch (InterruptedException e) {
+ if (service.isActive()) {
+ LOG.error("Get an unexpected interrupt when
distributing assignments to node, {}", e.getCause());
+ } else {
+ // service is off now just interrupt it.
+ Thread.currentThread().interrupt();
+ }
+ }
+ }
+ }
+
+ private void sendAssignmentsToNode(NodeAssignments assignments) {
+ SupervisorClient client =
SupervisorClient.getConfiguredClient(service.getConf(), assignments.getNode());
--- End diff --
SupervisorClient should be AutoClosable, so we can use java to ensure it is
closed.
---
