[
https://issues.apache.org/jira/browse/HIVE-26242?focusedWorklogId=785108&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-785108
]
ASF GitHub Bot logged work on HIVE-26242:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 27/Jun/22 14:04
Start Date: 27/Jun/22 14:04
Worklog Time Spent: 10m
Work Description: deniskuzZ commented on code in PR #3303:
URL: https://github.com/apache/hive/pull/3303#discussion_r907429293
##########
ql/src/java/org/apache/hadoop/hive/ql/txn/compactor/CompactionHeartbeatService.java:
##########
@@ -0,0 +1,222 @@
+/*
+ * 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 org.apache.hadoop.hive.ql.txn.compactor;
+
+import org.apache.commons.pool2.ObjectPool;
+import org.apache.commons.pool2.impl.GenericObjectPool;
+import org.apache.commons.pool2.impl.GenericObjectPoolConfig;
+import org.apache.hadoop.hive.conf.HiveConf;
+import org.apache.hadoop.hive.metastore.IMetaStoreClient;
+import org.apache.hadoop.hive.metastore.conf.MetastoreConf;
+import org.apache.hive.common.util.ShutdownHookManager;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.HashMap;
+import java.util.NoSuchElementException;
+import java.util.Objects;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+import static
org.apache.hive.common.util.HiveStringUtils.SHUTDOWN_HOOK_PRIORITY;
+
+/**
+ * Singleton service responsible for heartbeating the compaction transactions.
+ */
+class CompactionHeartbeatService {
+
+
+ private static final Logger LOG =
LoggerFactory.getLogger(CompactionHeartbeatService.class);
+
+ private static volatile CompactionHeartbeatService instance;
+
+ /**
+ * Return the singleton instance of this class.
+ * @param conf The {@link HiveConf} used to create the service. Used only
during the firsst call
+ * @return Returns the singleton {@link CompactionHeartbeatService}
+ * @throws IllegalStateException Thrown when the service has already been
shut down.
+ */
+ static CompactionHeartbeatService getInstance(HiveConf conf) {
+ if (instance == null) {
+ synchronized (CompactionHeartbeatService.class) {
+ if (instance == null) {
+ LOG.debug("Initializing compaction txn heartbeater service.");
+ instance = new CompactionHeartbeatService(conf);
+ ShutdownHookManager.addShutdownHook(() -> {
+ try {
+ instance.shutdown();
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ }
+ }, SHUTDOWN_HOOK_PRIORITY);
+ }
+ }
+ }
+ if (instance.heartbeatExecutor.isShutdown()) {
+ throw new IllegalStateException("The CompactionHeartbeatService is
already shut down!");
+ }
+ return instance;
+ }
+
+ private final ScheduledExecutorService heartbeatExecutor;
+ private final ObjectPool<IMetaStoreClient> clientPool;
+ private final long initialDelay;
+ private final long period;
+ private final HashMap<Long, TaskWrapper> tasks = new HashMap<>(30);
+
+ /**
+ * Starts the heartbeat for the given transaction
+ * @param txnId The id of the compaction txn
+ * @param lockId The id of the lock associated with the txn
+ * @param tableName Required for logging only
+ * @throws IllegalStateException Thrown when the heartbeat for the given txn
has already been started.
+ */
+ void startHeartbeat(long txnId, long lockId, String tableName) {
+ if (tasks.containsKey(txnId)) {
+ throw new IllegalStateException("Heartbeat already started for TXN " +
txnId);
+ }
+ LOG.info("Submitting heartbeat task for TXN {}", txnId);
+ CompactionHeartbeater heartbeater = new CompactionHeartbeater(txnId,
lockId, tableName);
+ Future<?> submittedTask =
heartbeatExecutor.scheduleAtFixedRate(heartbeater, initialDelay, period,
TimeUnit.MILLISECONDS);
+ tasks.put(txnId, new TaskWrapper(heartbeater, submittedTask));
+ }
+
+ /**
+ * Stops the heartbeat for the given transaction
+ * @param txnId The id of the compaction txn
+ * @throws IllegalStateException Thrown when there is no {@link
CompactionHeartbeater} task associated with the
+ * given txnId.
+ */
+ void stopHeartbeat(long txnId) throws InterruptedException {
+ LOG.info("Stopping heartbeat task for TXN {}", txnId);
+ TaskWrapper wrapper = tasks.get(txnId);
+ if (wrapper == null) {
+ throw new IllegalStateException("No registered heartbeat found for TXN "
+ txnId);
+ }
+ wrapper.future.cancel(false);
Review Comment:
Cancel does not remove the task from a scheduler. All it ensures is that
isDone() method always return true. This may lead to memory leaks if you keep
adding such tasks. You might end up with big pool of threads that cannot be
garbage collected as scheduler still has a reference.
You may want to use setRemoveOnCancelPolicy(true) in
ScheduledThreadPoolExecutor class , default is set to false.
Issue Time Tracking
-------------------
Worklog Id: (was: 785108)
Time Spent: 6h 40m (was: 6.5h)
> Compaction heartbeater improvements
> -----------------------------------
>
> Key: HIVE-26242
> URL: https://issues.apache.org/jira/browse/HIVE-26242
> Project: Hive
> Issue Type: Improvement
> Reporter: László Végh
> Assignee: László Végh
> Priority: Major
> Labels: pull-request-available
> Time Spent: 6h 40m
> Remaining Estimate: 0h
>
> The Compaction heartbeater should be improved the following ways:
> * The metastore clients should be reused between heartbeats and closed only
> at the end, when the transaction ends
> * Instead of having a dedicated heartbeater thread for each Compaction
> transaction, there should be shared a heartbeater executor where the
> heartbeat tasks can be scheduled/submitted.
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