[
https://issues.apache.org/jira/browse/HADOOP-17461?focusedWorklogId=792243&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-792243
]
ASF GitHub Bot logged work on HADOOP-17461:
-------------------------------------------
Author: ASF GitHub Bot
Created on: 18/Jul/22 16:48
Start Date: 18/Jul/22 16:48
Worklog Time Spent: 10m
Work Description: steveloughran commented on code in PR #4352:
URL: https://github.com/apache/hadoop/pull/4352#discussion_r920337912
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsContextImpl.java:
##########
@@ -0,0 +1,224 @@
+/*
+ * 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.fs.statistics.impl;
+
+import java.lang.ref.WeakReference;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.apache.hadoop.classification.VisibleForTesting;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.impl.WeakReferenceThreadMap;
+import org.apache.hadoop.fs.statistics.IOStatistics;
+import org.apache.hadoop.fs.statistics.IOStatisticsAggregator;
+import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
+
+import static
org.apache.hadoop.fs.CommonConfigurationKeys.THREAD_LEVEL_IOSTATISTICS_ENABLED;
+import static
org.apache.hadoop.fs.CommonConfigurationKeys.THREAD_LEVEL_IOSTATISTICS_ENABLED_DEFAULT;
+
+/**
+ * Implementing the IOStatisticsContext.
+ *
+ * A Context defined for IOStatistics collection per thread which captures
+ * each worker thread's work in FS streams and stores it in the form of
+ * IOStatisticsSnapshot if thread level aggregation is enabled else returning
+ * an instance of EmptyIOStatisticsStore for the FS. An active instance of
+ * the IOStatisticsContext can be used to collect the statistics.
+ *
+ * For the current thread the IOStatisticsSnapshot can be used as a way to
+ * move the IOStatistics data between applications using the Serializable
+ * nature of the class.
+ */
+public class IOStatisticsContextImpl implements IOStatisticsContext {
+ private static final Logger LOG =
+ LoggerFactory.getLogger(IOStatisticsContextImpl.class);
+ private static final boolean IS_THREAD_IOSTATS_ENABLED;
+
+ /**
+ * Active IOStatistics Context containing different worker thread's
+ * statistics. Weak Reference so that it gets cleaned up during GC and we
+ * avoid any memory leak issues due to long lived references.
+ */
+ private static final WeakReferenceThreadMap<IOStatisticsContext>
+ ACTIVE_IOSTATS_CONTEXT =
+ new WeakReferenceThreadMap<>(IOStatisticsContextImpl::createNewInstance,
+ IOStatisticsContextImpl::referenceLostContext
+ );
+
+ /**
+ * Collecting IOStatistics per thread.
+ */
+ private final WeakReferenceThreadMap<IOStatisticsSnapshot>
+ threadLevelIOStatisticsMap =
+ new WeakReferenceThreadMap<>(this::getIOStatisticsSnapshotFactory,
+ this::referenceLost);
+
+ static {
+ // Work out if the current context has thread level IOStatistics enabled.
+ final Configuration configuration = new Configuration();
+ IS_THREAD_IOSTATS_ENABLED =
+ configuration.getBoolean(THREAD_LEVEL_IOSTATISTICS_ENABLED,
+ THREAD_LEVEL_IOSTATISTICS_ENABLED_DEFAULT);
+ }
+
+ /**
+ * Creating a new IOStatisticsContext instance for a FS to be used. If
Review Comment:
cropped sentence at end
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsContextImpl.java:
##########
@@ -0,0 +1,224 @@
+/*
+ * 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.fs.statistics.impl;
+
+import java.lang.ref.WeakReference;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.apache.hadoop.classification.VisibleForTesting;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.impl.WeakReferenceThreadMap;
+import org.apache.hadoop.fs.statistics.IOStatistics;
+import org.apache.hadoop.fs.statistics.IOStatisticsAggregator;
+import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
+
+import static
org.apache.hadoop.fs.CommonConfigurationKeys.THREAD_LEVEL_IOSTATISTICS_ENABLED;
+import static
org.apache.hadoop.fs.CommonConfigurationKeys.THREAD_LEVEL_IOSTATISTICS_ENABLED_DEFAULT;
+
+/**
+ * Implementing the IOStatisticsContext.
+ *
+ * A Context defined for IOStatistics collection per thread which captures
+ * each worker thread's work in FS streams and stores it in the form of
+ * IOStatisticsSnapshot if thread level aggregation is enabled else returning
+ * an instance of EmptyIOStatisticsStore for the FS. An active instance of
+ * the IOStatisticsContext can be used to collect the statistics.
+ *
+ * For the current thread the IOStatisticsSnapshot can be used as a way to
+ * move the IOStatistics data between applications using the Serializable
+ * nature of the class.
+ */
+public class IOStatisticsContextImpl implements IOStatisticsContext {
+ private static final Logger LOG =
+ LoggerFactory.getLogger(IOStatisticsContextImpl.class);
+ private static final boolean IS_THREAD_IOSTATS_ENABLED;
+
+ /**
+ * Active IOStatistics Context containing different worker thread's
+ * statistics. Weak Reference so that it gets cleaned up during GC and we
+ * avoid any memory leak issues due to long lived references.
+ */
+ private static final WeakReferenceThreadMap<IOStatisticsContext>
+ ACTIVE_IOSTATS_CONTEXT =
+ new WeakReferenceThreadMap<>(IOStatisticsContextImpl::createNewInstance,
+ IOStatisticsContextImpl::referenceLostContext
+ );
+
+ /**
+ * Collecting IOStatistics per thread.
+ */
+ private final WeakReferenceThreadMap<IOStatisticsSnapshot>
+ threadLevelIOStatisticsMap =
+ new WeakReferenceThreadMap<>(this::getIOStatisticsSnapshotFactory,
+ this::referenceLost);
+
+ static {
+ // Work out if the current context has thread level IOStatistics enabled.
+ final Configuration configuration = new Configuration();
+ IS_THREAD_IOSTATS_ENABLED =
+ configuration.getBoolean(THREAD_LEVEL_IOSTATISTICS_ENABLED,
+ THREAD_LEVEL_IOSTATISTICS_ENABLED_DEFAULT);
+ }
+
+ /**
+ * Creating a new IOStatisticsContext instance for a FS to be used. If
+ *
+ * @param key Thread ID that represents which thread the context belongs to.
+ * @return an instance of IOStatisticsContext.
+ */
+ private static IOStatisticsContext createNewInstance(Long key) {
+ if (!IS_THREAD_IOSTATS_ENABLED) {
+ return new EmptyIOStatisticsContextImpl();
+ }
+ return new IOStatisticsContextImpl();
+ }
+
+ /**
+ * A Method to act as an IOStatisticsSnapshot factory, in a
+ * WeakReferenceThreadMap.
+ *
+ * @param key ThreadID.
+ * @return an Instance of IOStatisticsSnapshot.
+ */
+ private IOStatisticsSnapshot getIOStatisticsSnapshotFactory(Long key) {
+ return new IOStatisticsSnapshot();
+ }
+
+ /**
+ * In case of reference loss.
+ *
+ * @param key ThreadID.
+ */
+ private void referenceLost(Long key) {
+ LOG.debug("Reference lost for threadID: {}", key);
+ }
+
+ /**
+ * In case of reference loss for IOStatisticsContext.
+ *
+ * @param key ThreadID.
+ */
+ private static void referenceLostContext(Long key) {
+ LOG.debug("Reference lost for threadID for the context: {}", key);
+ }
+
+ /**
+ * Get the current thread's IOStatisticsContext instance. If no instance is
+ * present for this thread ID, create one using the factory.
+ *
+ * @return instance of IOStatisticsContext.
+ */
+ @Override
+ public IOStatisticsContext getCurrentIOStatisticsContext() {
+ return ACTIVE_IOSTATS_CONTEXT.getForCurrentThread();
+ }
+
+ /**
+ * A Method to get the IOStatisticsAggregator of the currentThread. This
+ * denotes the aggregated IOStatistics per thread.
+ *
+ * @return the instance of IOStatisticsAggregator for the current thread.
+ */
+ @Override
+ public IOStatisticsAggregator getThreadIOStatisticsAggregator() {
+ // If the current Thread ID already have an aggregator assigned, return
+ // that.
+ boolean isThreadIOStatsPresent =
Review Comment:
use the context map and ask it for its aggregator
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/WeakReferenceThreadMap.java:
##########
@@ -48,7 +49,15 @@ public long currentThreadId() {
}
public V setForCurrentThread(V newVal) {
- return put(currentThreadId(), newVal);
+ long id = currentThreadId();
Review Comment:
do we need a precondition on a null value here?
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsContext.java:
##########
@@ -20,22 +20,28 @@
import org.apache.hadoop.fs.statistics.IOStatisticsAggregator;
import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
+import org.apache.hadoop.fs.statistics.IOStatisticsSource;
/**
* An interface defined to capture thread-level IOStatistics by using per
- * thread context consisting of IOStatisticsSnapshot thread map for each
- * worker thread.
- * EmptyIOStatisticsSource is returned as an aggregator if this feature is
- * disabled, resulting in a no-op in aggregation.
+ * thread context.
+ * <p>
+ * The aggregator should be collected in their constructor by
statistics-generating
+ * classes to obtain the aggregator to update <i>across all threads</i>.
+ * <p>
+ * The {@link #snapshot()} call creates a snapshot of the statistics;
+ * <p>
+ * The {@link #reset()} call resets the statistics in the current thread so
+ * that later snapshots will get the incremental data.
*/
-public interface IOStatisticsContext {
+public interface IOStatisticsContext extends IOStatisticsSource {
/**
- * Get the current thread's IOStatisticsContext.
+ * Get the IOStatisticsAggregator for the current thread.
Review Comment:
"for the context"
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsContext.java:
##########
@@ -20,22 +20,28 @@
import org.apache.hadoop.fs.statistics.IOStatisticsAggregator;
import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
+import org.apache.hadoop.fs.statistics.IOStatisticsSource;
/**
* An interface defined to capture thread-level IOStatistics by using per
- * thread context consisting of IOStatisticsSnapshot thread map for each
- * worker thread.
- * EmptyIOStatisticsSource is returned as an aggregator if this feature is
- * disabled, resulting in a no-op in aggregation.
+ * thread context.
+ * <p>
+ * The aggregator should be collected in their constructor by
statistics-generating
+ * classes to obtain the aggregator to update <i>across all threads</i>.
+ * <p>
+ * The {@link #snapshot()} call creates a snapshot of the statistics;
+ * <p>
+ * The {@link #reset()} call resets the statistics in the current thread so
+ * that later snapshots will get the incremental data.
*/
-public interface IOStatisticsContext {
+public interface IOStatisticsContext extends IOStatisticsSource {
/**
- * Get the current thread's IOStatisticsContext.
+ * Get the IOStatisticsAggregator for the current thread.
*
- * @return instance of IOStatisticsContext for the current thread.
+ * @return return the aggregator for current thread.
*/
- IOStatisticsContext getCurrentIOStatisticsContext();
+ IOStatisticsAggregator getAggregator();
/**
* Capture the snapshot of current thread's IOStatistics.
Review Comment:
"of the context's"
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsContextImpl.java:
##########
@@ -0,0 +1,224 @@
+/*
+ * 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.fs.statistics.impl;
+
+import java.lang.ref.WeakReference;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.apache.hadoop.classification.VisibleForTesting;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.impl.WeakReferenceThreadMap;
+import org.apache.hadoop.fs.statistics.IOStatistics;
+import org.apache.hadoop.fs.statistics.IOStatisticsAggregator;
+import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
+
+import static
org.apache.hadoop.fs.CommonConfigurationKeys.THREAD_LEVEL_IOSTATISTICS_ENABLED;
+import static
org.apache.hadoop.fs.CommonConfigurationKeys.THREAD_LEVEL_IOSTATISTICS_ENABLED_DEFAULT;
+
+/**
+ * Implementing the IOStatisticsContext.
+ *
+ * A Context defined for IOStatistics collection per thread which captures
+ * each worker thread's work in FS streams and stores it in the form of
+ * IOStatisticsSnapshot if thread level aggregation is enabled else returning
+ * an instance of EmptyIOStatisticsStore for the FS. An active instance of
+ * the IOStatisticsContext can be used to collect the statistics.
+ *
+ * For the current thread the IOStatisticsSnapshot can be used as a way to
+ * move the IOStatistics data between applications using the Serializable
+ * nature of the class.
+ */
+public class IOStatisticsContextImpl implements IOStatisticsContext {
+ private static final Logger LOG =
+ LoggerFactory.getLogger(IOStatisticsContextImpl.class);
+ private static final boolean IS_THREAD_IOSTATS_ENABLED;
+
+ /**
+ * Active IOStatistics Context containing different worker thread's
+ * statistics. Weak Reference so that it gets cleaned up during GC and we
+ * avoid any memory leak issues due to long lived references.
+ */
+ private static final WeakReferenceThreadMap<IOStatisticsContext>
+ ACTIVE_IOSTATS_CONTEXT =
+ new WeakReferenceThreadMap<>(IOStatisticsContextImpl::createNewInstance,
+ IOStatisticsContextImpl::referenceLostContext
+ );
+
+ /**
+ * Collecting IOStatistics per thread.
+ */
+ private final WeakReferenceThreadMap<IOStatisticsSnapshot>
Review Comment:
the context map can support this; just look it up and call
getThreadIOStatisticsAggregator() on it
##########
hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/ITestS3AIOStatisticsContext.java:
##########
@@ -66,20 +66,21 @@ public void setUp() throws Exception {
*/
@BeforeClass
public static void beforeClass() throws Exception {
- currentIOStatisticsContext().resetThreadIOStatisticsForCurrentThread();
// Do some work in constructor thread.
S3AFileSystem fs = new S3AFileSystem();
Configuration conf = new Configuration();
fs.initialize(new URI(conf.get(TEST_FS_S3A_NAME)), conf);
Path path = new Path("testConstructor");
+ IOStatisticsContextImpl ioStatisticsContext = fs.getIoStatisticsContext();
Review Comment:
should be IOStatisticsContext
##########
hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/S3AFileSystem.java:
##########
@@ -5231,4 +5234,13 @@ public RequestFactory getRequestFactory() {
public boolean isCSEEnabled() {
return isCSEEnabled;
}
+
+ /**
+ * Get the FileSystem's IOStatisticsContext.
+ * @return the instance of IOStatisticsContextImpl.
+ */
+ @VisibleForTesting
+ public IOStatisticsContextImpl getIoStatisticsContext() {
Review Comment:
don't cast. if tests want to cast it, and they know it is safe, they can do
so
##########
hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/commit/AbstractCommitITest.java:
##########
@@ -66,6 +70,12 @@ public abstract class AbstractCommitITest extends
AbstractS3ATestBase {
private static final Logger LOG =
LoggerFactory.getLogger(AbstractCommitITest.class);
+ /**
+ * Job statistics accrued across all test cases
Review Comment:
needs a .
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsContext.java:
##########
@@ -20,22 +20,28 @@
import org.apache.hadoop.fs.statistics.IOStatisticsAggregator;
import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
+import org.apache.hadoop.fs.statistics.IOStatisticsSource;
/**
* An interface defined to capture thread-level IOStatistics by using per
- * thread context consisting of IOStatisticsSnapshot thread map for each
- * worker thread.
- * EmptyIOStatisticsSource is returned as an aggregator if this feature is
- * disabled, resulting in a no-op in aggregation.
+ * thread context.
+ * <p>
+ * The aggregator should be collected in their constructor by
statistics-generating
+ * classes to obtain the aggregator to update <i>across all threads</i>.
+ * <p>
+ * The {@link #snapshot()} call creates a snapshot of the statistics;
+ * <p>
+ * The {@link #reset()} call resets the statistics in the current thread so
+ * that later snapshots will get the incremental data.
*/
-public interface IOStatisticsContext {
+public interface IOStatisticsContext extends IOStatisticsSource {
/**
- * Get the current thread's IOStatisticsContext.
+ * Get the IOStatisticsAggregator for the current thread.
*
- * @return instance of IOStatisticsContext for the current thread.
+ * @return return the aggregator for current thread.
Review Comment:
"for the context"
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsContextImpl.java:
##########
@@ -0,0 +1,224 @@
+/*
+ * 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.fs.statistics.impl;
+
+import java.lang.ref.WeakReference;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.apache.hadoop.classification.VisibleForTesting;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.impl.WeakReferenceThreadMap;
+import org.apache.hadoop.fs.statistics.IOStatistics;
+import org.apache.hadoop.fs.statistics.IOStatisticsAggregator;
+import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
+
+import static
org.apache.hadoop.fs.CommonConfigurationKeys.THREAD_LEVEL_IOSTATISTICS_ENABLED;
+import static
org.apache.hadoop.fs.CommonConfigurationKeys.THREAD_LEVEL_IOSTATISTICS_ENABLED_DEFAULT;
+
+/**
+ * Implementing the IOStatisticsContext.
+ *
+ * A Context defined for IOStatistics collection per thread which captures
+ * each worker thread's work in FS streams and stores it in the form of
+ * IOStatisticsSnapshot if thread level aggregation is enabled else returning
+ * an instance of EmptyIOStatisticsStore for the FS. An active instance of
+ * the IOStatisticsContext can be used to collect the statistics.
+ *
+ * For the current thread the IOStatisticsSnapshot can be used as a way to
+ * move the IOStatistics data between applications using the Serializable
+ * nature of the class.
+ */
+public class IOStatisticsContextImpl implements IOStatisticsContext {
+ private static final Logger LOG =
+ LoggerFactory.getLogger(IOStatisticsContextImpl.class);
+ private static final boolean IS_THREAD_IOSTATS_ENABLED;
+
+ /**
+ * Active IOStatistics Context containing different worker thread's
+ * statistics. Weak Reference so that it gets cleaned up during GC and we
+ * avoid any memory leak issues due to long lived references.
+ */
+ private static final WeakReferenceThreadMap<IOStatisticsContext>
+ ACTIVE_IOSTATS_CONTEXT =
+ new WeakReferenceThreadMap<>(IOStatisticsContextImpl::createNewInstance,
+ IOStatisticsContextImpl::referenceLostContext
+ );
+
+ /**
+ * Collecting IOStatistics per thread.
+ */
+ private final WeakReferenceThreadMap<IOStatisticsSnapshot>
+ threadLevelIOStatisticsMap =
+ new WeakReferenceThreadMap<>(this::getIOStatisticsSnapshotFactory,
+ this::referenceLost);
+
+ static {
+ // Work out if the current context has thread level IOStatistics enabled.
+ final Configuration configuration = new Configuration();
+ IS_THREAD_IOSTATS_ENABLED =
+ configuration.getBoolean(THREAD_LEVEL_IOSTATISTICS_ENABLED,
+ THREAD_LEVEL_IOSTATISTICS_ENABLED_DEFAULT);
+ }
+
+ /**
+ * Creating a new IOStatisticsContext instance for a FS to be used. If
+ *
+ * @param key Thread ID that represents which thread the context belongs to.
+ * @return an instance of IOStatisticsContext.
+ */
+ private static IOStatisticsContext createNewInstance(Long key) {
+ if (!IS_THREAD_IOSTATS_ENABLED) {
+ return new EmptyIOStatisticsContextImpl();
+ }
+ return new IOStatisticsContextImpl();
+ }
+
+ /**
+ * A Method to act as an IOStatisticsSnapshot factory, in a
+ * WeakReferenceThreadMap.
+ *
+ * @param key ThreadID.
+ * @return an Instance of IOStatisticsSnapshot.
+ */
+ private IOStatisticsSnapshot getIOStatisticsSnapshotFactory(Long key) {
+ return new IOStatisticsSnapshot();
+ }
+
+ /**
+ * In case of reference loss.
+ *
+ * @param key ThreadID.
+ */
+ private void referenceLost(Long key) {
+ LOG.debug("Reference lost for threadID: {}", key);
+ }
+
+ /**
+ * In case of reference loss for IOStatisticsContext.
+ *
+ * @param key ThreadID.
+ */
+ private static void referenceLostContext(Long key) {
+ LOG.debug("Reference lost for threadID for the context: {}", key);
+ }
+
+ /**
+ * Get the current thread's IOStatisticsContext instance. If no instance is
+ * present for this thread ID, create one using the factory.
+ *
+ * @return instance of IOStatisticsContext.
+ */
+ @Override
+ public IOStatisticsContext getCurrentIOStatisticsContext() {
+ return ACTIVE_IOSTATS_CONTEXT.getForCurrentThread();
+ }
+
+ /**
+ * A Method to get the IOStatisticsAggregator of the currentThread. This
+ * denotes the aggregated IOStatistics per thread.
+ *
+ * @return the instance of IOStatisticsAggregator for the current thread.
+ */
+ @Override
+ public IOStatisticsAggregator getThreadIOStatisticsAggregator() {
+ // If the current Thread ID already have an aggregator assigned, return
+ // that.
+ boolean isThreadIOStatsPresent =
+ threadLevelIOStatisticsMap.containsKey(Thread.currentThread().getId());
+ if (isThreadIOStatsPresent) {
+ return threadLevelIOStatisticsMap.getForCurrentThread();
+ }
+ LOG.debug("No thread iostats present creating it for :{}",
+ Thread.currentThread().getId());
+ // If no aggregator is defined to the thread ID, create one and assign it.
+ IOStatisticsSnapshot ioStatisticsSnapshot = new IOStatisticsSnapshot();
+ setThreadIOStatistics(ioStatisticsSnapshot);
+ return ioStatisticsSnapshot;
+ }
+
+ /**
+ * Set the IOStatisticsSnapshot for the current context for a specific
+ * thread.
+ *
+ * @param ioStatisticsSnapshot IOStatisticsAggregator instance for the
+ * current thread.
+ */
+ public void setThreadIOStatistics(
+ IOStatisticsSnapshot ioStatisticsSnapshot) {
+ threadLevelIOStatisticsMap.setForCurrentThread(ioStatisticsSnapshot);
+ }
+
+ /**
+ * Returns a snapshot of the current thread's IOStatistics.
+ *
+ * @return IOStatisticsSnapshot of the current thread.
+ */
+ @Override
+ public IOStatisticsSnapshot snapshot() {
+ if (threadLevelIOStatisticsMap.containsKey(getCurrentThreadID())) {
+ return threadLevelIOStatisticsMap.get(getCurrentThreadID());
+ }
+ return new IOStatisticsSnapshot();
+ }
+
+ /**
+ * Reset the thread IOStatistics for current thread.
+ */
+ @Override
+ public void reset() {
+ WeakReference<IOStatisticsSnapshot> ioStatisticsSnapshotRef =
+ threadLevelIOStatisticsMap.lookup(getCurrentThreadID());
+ if (ioStatisticsSnapshotRef != null) {
+ IOStatisticsSnapshot ioStatisticsSnapshot =
ioStatisticsSnapshotRef.get();
+ // Get the snapshot for the current thread ID and clear it.
+ if(ioStatisticsSnapshot != null) {
+ ioStatisticsSnapshot.clear();
+ }
+ }
+ }
+
+ /**
+ * Get the current thread's ID.
+ * @return long value of the thread ID.
+ */
+ private Long getCurrentThreadID() {
+ return Thread.currentThread().getId();
+ }
+
+ /**
+ * Get thread ID specific IOStatistics values.
+ *
+ * @param testThreadId thread ID.
+ * @return IOStatistics instance.
+ */
+ @VisibleForTesting
+ public IOStatistics getThreadSpecificIOStatistics(long testThreadId) {
Review Comment:
tests should also look at the context map; lets them test more
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsContext.java:
##########
@@ -20,22 +20,28 @@
import org.apache.hadoop.fs.statistics.IOStatisticsAggregator;
import org.apache.hadoop.fs.statistics.IOStatisticsSnapshot;
+import org.apache.hadoop.fs.statistics.IOStatisticsSource;
/**
* An interface defined to capture thread-level IOStatistics by using per
- * thread context consisting of IOStatisticsSnapshot thread map for each
- * worker thread.
- * EmptyIOStatisticsSource is returned as an aggregator if this feature is
- * disabled, resulting in a no-op in aggregation.
+ * thread context.
+ * <p>
+ * The aggregator should be collected in their constructor by
statistics-generating
+ * classes to obtain the aggregator to update <i>across all threads</i>.
+ * <p>
+ * The {@link #snapshot()} call creates a snapshot of the statistics;
+ * <p>
+ * The {@link #reset()} call resets the statistics in the current thread so
+ * that later snapshots will get the incremental data.
*/
-public interface IOStatisticsContext {
+public interface IOStatisticsContext extends IOStatisticsSource {
Review Comment:
all the javadocs saying "the current thread" except for the static method to
do the lookup MUST be changed to just say ""the context"
##########
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/WeakReferenceThreadMap.java:
##########
@@ -48,7 +49,15 @@ public long currentThreadId() {
}
public V setForCurrentThread(V newVal) {
- return put(currentThreadId(), newVal);
+ long id = currentThreadId();
+
+ // if the same object is already in the map, just return it.
+ WeakReference<V> ref = lookup(id);
+ if (ref != null && ref.get() == newVal) {
Review Comment:
if there's been a GC ref.get could be null. now, as we are doing == and not
Object.equals that is safe.
we should mention that as a comment
Issue Time Tracking
-------------------
Worklog Id: (was: 792243)
Time Spent: 5.5h (was: 5h 20m)
> Add thread-level IOStatistics Context
> -------------------------------------
>
> Key: HADOOP-17461
> URL: https://issues.apache.org/jira/browse/HADOOP-17461
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs, fs/azure, fs/s3
> Affects Versions: 3.3.1
> Reporter: Steve Loughran
> Assignee: Mehakmeet Singh
> Priority: Major
> Labels: pull-request-available
> Time Spent: 5.5h
> Remaining Estimate: 0h
>
> For effective reporting of the iostatistics of individual worker threads, we
> need a thread-level context which IO components update.
> * this contact needs to be passed in two background thread forming work on
> behalf of a task.
> * IO Components (streams, iterators, filesystems) need to update this context
> statistics as they perform work
> * Without double counting anything.
> I imagine a ThreadLocal IOStatisticContext which will be updated in the
> FileSystem API Calls. This context MUST be passed into the background threads
> used by a task, so that IO is correctly aggregated.
> I don't want streams, listIterators &c to do the updating as there is more
> risk of double counting. However, we need to see their statistics if we want
> to know things like "bytes discarded in backwards seeks". And I don't want to
> be updating a shared context object on every read() call.
> If all we want is store IO (HEAD, GET, DELETE, list performance etc) then the
> FS is sufficient.
> If we do want the stream-specific detail, then I propose
> * caching the context in the constructor
> * updating it only in close() or unbuffer() (as we do from S3AInputStream to
> S3AInstrumenation)
> * excluding those we know the FS already collects.
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