gaoyunhaii commented on a change in pull request #13924:
URL: https://github.com/apache/flink/pull/13924#discussion_r601153174
##########
File path:
flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/SortMergeSubpartitionReader.java
##########
@@ -19,154 +19,180 @@
package org.apache.flink.runtime.io.network.partition;
import org.apache.flink.core.memory.MemorySegment;
-import org.apache.flink.core.memory.MemorySegmentFactory;
import org.apache.flink.runtime.io.network.buffer.Buffer;
import org.apache.flink.runtime.io.network.buffer.BufferRecycler;
import
org.apache.flink.runtime.io.network.partition.ResultSubpartition.BufferAndBacklog;
-import org.apache.flink.util.ExceptionUtils;
-import org.apache.flink.util.IOUtils;
import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.Queue;
+import static org.apache.flink.util.Preconditions.checkArgument;
import static org.apache.flink.util.Preconditions.checkNotNull;
-import static org.apache.flink.util.Preconditions.checkState;
/** Subpartition data reader for {@link SortMergeResultPartition}. */
-public class SortMergeSubpartitionReader implements ResultSubpartitionView,
BufferRecycler {
+public class SortMergeSubpartitionReader
+ implements ResultSubpartitionView,
Comparable<SortMergeSubpartitionReader> {
- private static final int NUM_READ_BUFFERS = 2;
+ private final Object lock = new Object();
/** Target {@link SortMergeResultPartition} to read data from. */
private final SortMergeResultPartition partition;
/** Listener to notify when data is available. */
private final BufferAvailabilityListener availabilityListener;
- /** Unmanaged memory used as read buffers. */
- private final Queue<MemorySegment> readBuffers = new ArrayDeque<>();
-
- /** Buffers read by the file reader. */
+ /** Buffers already read which can be consumed by netty thread. */
+ @GuardedBy("lock")
private final Queue<Buffer> buffersRead = new ArrayDeque<>();
/** File reader used to read buffer from. */
private final PartitionedFileReader fileReader;
- /** Number of remaining non-event buffers to read. */
+ /** Number of remaining non-event buffers in the buffer queue. */
+ @GuardedBy("lock")
private int dataBufferBacklog;
/** Whether this reader is released or not. */
+ @GuardedBy("lock")
private boolean isReleased;
+ /** Cause of failure which should be propagated to the consumer. */
+ @GuardedBy("lock")
+ private Throwable failureCause;
+
/** Sequence number of the next buffer to be sent to the consumer. */
private int sequenceNumber;
public SortMergeSubpartitionReader(
- int subpartitionIndex,
- int dataBufferBacklog,
- int bufferSize,
SortMergeResultPartition partition,
BufferAvailabilityListener listener,
- PartitionedFile partitionedFile)
- throws IOException {
+ PartitionedFileReader fileReader) {
this.partition = checkNotNull(partition);
this.availabilityListener = checkNotNull(listener);
- this.dataBufferBacklog = dataBufferBacklog;
-
- // allocate two pieces of unmanaged segments for data reading
- for (int i = 0; i < NUM_READ_BUFFERS; i++) {
- this.readBuffers.add(
-
MemorySegmentFactory.allocateUnpooledOffHeapMemory(bufferSize, null));
- }
-
- this.fileReader = new PartitionedFileReader(partitionedFile,
subpartitionIndex);
- try {
- readBuffers();
- } catch (Throwable throwable) {
- // ensure that the file reader is closed when any exception occurs
- IOUtils.closeQuietly(fileReader);
- throw throwable;
- }
+ this.fileReader = checkNotNull(fileReader);
}
@Nullable
@Override
public BufferAndBacklog getNextBuffer() {
- checkState(!isReleased, "Reader is already released.");
+ synchronized (lock) {
+ Buffer buffer = buffersRead.poll();
+ if (buffer == null) {
+ return null;
+ }
+
+ if (buffer.isBuffer()) {
+ --dataBufferBacklog;
+ }
- Buffer buffer = buffersRead.poll();
- if (buffer == null) {
- return null;
+ Buffer lookAhead = buffersRead.peek();
+ return BufferAndBacklog.fromBufferAndLookahead(
+ buffer,
+ lookAhead == null ? Buffer.DataType.NONE :
lookAhead.getDataType(),
+ dataBufferBacklog,
+ sequenceNumber++);
}
+ }
- if (buffer.isBuffer()) {
- --dataBufferBacklog;
+ private void addBuffer(Buffer buffer) {
+ boolean notifyAvailable;
+ synchronized (lock) {
+ if (isReleased) {
+ buffer.recycleBuffer();
+ return;
+ }
+
+ notifyAvailable = buffersRead.isEmpty();
+
+ buffersRead.add(buffer);
+ if (buffer.isBuffer()) {
+ ++dataBufferBacklog;
+ }
}
- final Buffer lookAhead = buffersRead.peek();
+ if (notifyAvailable) {
+ notifyDataAvailable();
+ }
+ }
+
+ boolean readBuffers(Queue<MemorySegment> buffers, BufferRecycler recycler)
throws IOException {
+ while (!buffers.isEmpty()) {
Review comment:
Perhaps we could limit the maximum accumulated amount of buffers for a
single sub-partition. But it should be an optimization and we could do it
separately in the future after we have assessed the suitable threshold.
##########
File path:
flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/SortMergeSubpartitionReader.java
##########
@@ -19,154 +19,180 @@
package org.apache.flink.runtime.io.network.partition;
import org.apache.flink.core.memory.MemorySegment;
-import org.apache.flink.core.memory.MemorySegmentFactory;
import org.apache.flink.runtime.io.network.buffer.Buffer;
import org.apache.flink.runtime.io.network.buffer.BufferRecycler;
import
org.apache.flink.runtime.io.network.partition.ResultSubpartition.BufferAndBacklog;
-import org.apache.flink.util.ExceptionUtils;
-import org.apache.flink.util.IOUtils;
import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.Queue;
+import static org.apache.flink.util.Preconditions.checkArgument;
import static org.apache.flink.util.Preconditions.checkNotNull;
-import static org.apache.flink.util.Preconditions.checkState;
/** Subpartition data reader for {@link SortMergeResultPartition}. */
-public class SortMergeSubpartitionReader implements ResultSubpartitionView,
BufferRecycler {
+public class SortMergeSubpartitionReader
+ implements ResultSubpartitionView,
Comparable<SortMergeSubpartitionReader> {
- private static final int NUM_READ_BUFFERS = 2;
+ private final Object lock = new Object();
/** Target {@link SortMergeResultPartition} to read data from. */
private final SortMergeResultPartition partition;
/** Listener to notify when data is available. */
private final BufferAvailabilityListener availabilityListener;
- /** Unmanaged memory used as read buffers. */
- private final Queue<MemorySegment> readBuffers = new ArrayDeque<>();
-
- /** Buffers read by the file reader. */
+ /** Buffers already read which can be consumed by netty thread. */
+ @GuardedBy("lock")
private final Queue<Buffer> buffersRead = new ArrayDeque<>();
/** File reader used to read buffer from. */
private final PartitionedFileReader fileReader;
- /** Number of remaining non-event buffers to read. */
+ /** Number of remaining non-event buffers in the buffer queue. */
+ @GuardedBy("lock")
private int dataBufferBacklog;
/** Whether this reader is released or not. */
+ @GuardedBy("lock")
private boolean isReleased;
+ /** Cause of failure which should be propagated to the consumer. */
+ @GuardedBy("lock")
+ private Throwable failureCause;
+
/** Sequence number of the next buffer to be sent to the consumer. */
private int sequenceNumber;
public SortMergeSubpartitionReader(
- int subpartitionIndex,
- int dataBufferBacklog,
- int bufferSize,
SortMergeResultPartition partition,
BufferAvailabilityListener listener,
- PartitionedFile partitionedFile)
- throws IOException {
+ PartitionedFileReader fileReader) {
this.partition = checkNotNull(partition);
this.availabilityListener = checkNotNull(listener);
- this.dataBufferBacklog = dataBufferBacklog;
-
- // allocate two pieces of unmanaged segments for data reading
- for (int i = 0; i < NUM_READ_BUFFERS; i++) {
- this.readBuffers.add(
-
MemorySegmentFactory.allocateUnpooledOffHeapMemory(bufferSize, null));
- }
-
- this.fileReader = new PartitionedFileReader(partitionedFile,
subpartitionIndex);
- try {
- readBuffers();
- } catch (Throwable throwable) {
- // ensure that the file reader is closed when any exception occurs
- IOUtils.closeQuietly(fileReader);
- throw throwable;
- }
+ this.fileReader = checkNotNull(fileReader);
}
@Nullable
@Override
public BufferAndBacklog getNextBuffer() {
- checkState(!isReleased, "Reader is already released.");
+ synchronized (lock) {
+ Buffer buffer = buffersRead.poll();
+ if (buffer == null) {
+ return null;
+ }
+
+ if (buffer.isBuffer()) {
+ --dataBufferBacklog;
+ }
- Buffer buffer = buffersRead.poll();
- if (buffer == null) {
- return null;
+ Buffer lookAhead = buffersRead.peek();
+ return BufferAndBacklog.fromBufferAndLookahead(
+ buffer,
+ lookAhead == null ? Buffer.DataType.NONE :
lookAhead.getDataType(),
+ dataBufferBacklog,
+ sequenceNumber++);
}
+ }
- if (buffer.isBuffer()) {
- --dataBufferBacklog;
+ private void addBuffer(Buffer buffer) {
+ boolean notifyAvailable;
+ synchronized (lock) {
+ if (isReleased) {
+ buffer.recycleBuffer();
+ return;
+ }
+
+ notifyAvailable = buffersRead.isEmpty();
+
+ buffersRead.add(buffer);
+ if (buffer.isBuffer()) {
+ ++dataBufferBacklog;
+ }
}
- final Buffer lookAhead = buffersRead.peek();
+ if (notifyAvailable) {
+ notifyDataAvailable();
+ }
+ }
+
+ boolean readBuffers(Queue<MemorySegment> buffers, BufferRecycler recycler)
throws IOException {
Review comment:
We may add a comment here on that this method is running in separate IO
threads.
##########
File path:
flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/SortMergeSubpartitionReader.java
##########
@@ -19,154 +19,180 @@
package org.apache.flink.runtime.io.network.partition;
import org.apache.flink.core.memory.MemorySegment;
-import org.apache.flink.core.memory.MemorySegmentFactory;
import org.apache.flink.runtime.io.network.buffer.Buffer;
import org.apache.flink.runtime.io.network.buffer.BufferRecycler;
import
org.apache.flink.runtime.io.network.partition.ResultSubpartition.BufferAndBacklog;
-import org.apache.flink.util.ExceptionUtils;
-import org.apache.flink.util.IOUtils;
import javax.annotation.Nullable;
+import javax.annotation.concurrent.GuardedBy;
import java.io.IOException;
import java.util.ArrayDeque;
import java.util.Queue;
+import static org.apache.flink.util.Preconditions.checkArgument;
import static org.apache.flink.util.Preconditions.checkNotNull;
-import static org.apache.flink.util.Preconditions.checkState;
/** Subpartition data reader for {@link SortMergeResultPartition}. */
-public class SortMergeSubpartitionReader implements ResultSubpartitionView,
BufferRecycler {
+public class SortMergeSubpartitionReader
+ implements ResultSubpartitionView,
Comparable<SortMergeSubpartitionReader> {
- private static final int NUM_READ_BUFFERS = 2;
+ private final Object lock = new Object();
/** Target {@link SortMergeResultPartition} to read data from. */
private final SortMergeResultPartition partition;
/** Listener to notify when data is available. */
private final BufferAvailabilityListener availabilityListener;
- /** Unmanaged memory used as read buffers. */
- private final Queue<MemorySegment> readBuffers = new ArrayDeque<>();
-
- /** Buffers read by the file reader. */
+ /** Buffers already read which can be consumed by netty thread. */
+ @GuardedBy("lock")
private final Queue<Buffer> buffersRead = new ArrayDeque<>();
/** File reader used to read buffer from. */
private final PartitionedFileReader fileReader;
- /** Number of remaining non-event buffers to read. */
+ /** Number of remaining non-event buffers in the buffer queue. */
+ @GuardedBy("lock")
private int dataBufferBacklog;
/** Whether this reader is released or not. */
+ @GuardedBy("lock")
private boolean isReleased;
+ /** Cause of failure which should be propagated to the consumer. */
+ @GuardedBy("lock")
+ private Throwable failureCause;
+
/** Sequence number of the next buffer to be sent to the consumer. */
private int sequenceNumber;
public SortMergeSubpartitionReader(
- int subpartitionIndex,
- int dataBufferBacklog,
- int bufferSize,
SortMergeResultPartition partition,
BufferAvailabilityListener listener,
- PartitionedFile partitionedFile)
- throws IOException {
+ PartitionedFileReader fileReader) {
this.partition = checkNotNull(partition);
this.availabilityListener = checkNotNull(listener);
- this.dataBufferBacklog = dataBufferBacklog;
-
- // allocate two pieces of unmanaged segments for data reading
- for (int i = 0; i < NUM_READ_BUFFERS; i++) {
- this.readBuffers.add(
-
MemorySegmentFactory.allocateUnpooledOffHeapMemory(bufferSize, null));
- }
-
- this.fileReader = new PartitionedFileReader(partitionedFile,
subpartitionIndex);
- try {
- readBuffers();
- } catch (Throwable throwable) {
- // ensure that the file reader is closed when any exception occurs
- IOUtils.closeQuietly(fileReader);
- throw throwable;
- }
+ this.fileReader = checkNotNull(fileReader);
}
@Nullable
@Override
public BufferAndBacklog getNextBuffer() {
- checkState(!isReleased, "Reader is already released.");
+ synchronized (lock) {
+ Buffer buffer = buffersRead.poll();
+ if (buffer == null) {
+ return null;
+ }
+
+ if (buffer.isBuffer()) {
+ --dataBufferBacklog;
+ }
- Buffer buffer = buffersRead.poll();
- if (buffer == null) {
- return null;
+ Buffer lookAhead = buffersRead.peek();
+ return BufferAndBacklog.fromBufferAndLookahead(
+ buffer,
+ lookAhead == null ? Buffer.DataType.NONE :
lookAhead.getDataType(),
+ dataBufferBacklog,
+ sequenceNumber++);
}
+ }
- if (buffer.isBuffer()) {
- --dataBufferBacklog;
+ private void addBuffer(Buffer buffer) {
+ boolean notifyAvailable;
+ synchronized (lock) {
+ if (isReleased) {
+ buffer.recycleBuffer();
+ return;
+ }
+
+ notifyAvailable = buffersRead.isEmpty();
+
+ buffersRead.add(buffer);
+ if (buffer.isBuffer()) {
+ ++dataBufferBacklog;
+ }
}
- final Buffer lookAhead = buffersRead.peek();
+ if (notifyAvailable) {
+ notifyDataAvailable();
+ }
+ }
+
+ boolean readBuffers(Queue<MemorySegment> buffers, BufferRecycler recycler)
throws IOException {
+ while (!buffers.isEmpty()) {
+ MemorySegment segment = buffers.poll();
- return BufferAndBacklog.fromBufferAndLookahead(
- buffer,
- lookAhead == null ? Buffer.DataType.NONE :
lookAhead.getDataType(),
- dataBufferBacklog,
- sequenceNumber++);
+ Buffer buffer;
+ try {
+ if ((buffer = fileReader.readCurrentRegion(segment, recycler))
== null) {
+ buffers.add(segment);
+ break;
+ }
+ } catch (Throwable throwable) {
+ buffers.add(segment);
+ throw throwable;
+ }
+ addBuffer(buffer);
+ }
+ return fileReader.hasRemaining();
}
- void readBuffers() throws IOException {
- // we do not need to recycle the allocated segment here if any
exception occurs
- // for this subpartition reader will be released so no resource will
be leaked
- MemorySegment segment;
- while ((segment = readBuffers.poll()) != null) {
- Buffer buffer = fileReader.readBuffer(segment, this);
- if (buffer == null) {
- readBuffers.add(segment);
- break;
+ void fail(Throwable throwable) {
+ checkArgument(throwable != null, "Must be not null.");
+
+ synchronized (lock) {
+ if (isReleased) {
+ return;
+ }
+
+ if (failureCause == null) {
+ failureCause = throwable;
}
- buffersRead.add(buffer);
}
+
+ releaseAllResources();
Review comment:
Could we extract a new `releaseResourceUnsafe(@Nullable Throwable
throawable)` method and call it in both `fail()` and `releaseAllResource()`
method ? Then we do not need to run duplicate `if (isReleased) {..}`
##########
File path:
flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/SortMergeSubpartitionReader.java
##########
@@ -176,21 +202,28 @@ public void resumeConsumption() {
@Override
public Throwable getFailureCause() {
- // we can never throw an error after this was created
- return null;
+ synchronized (lock) {
+ return failureCause;
+ }
}
@Override
public boolean isAvailable(int numCreditsAvailable) {
- if (numCreditsAvailable > 0) {
- return !buffersRead.isEmpty();
- }
+ synchronized (lock) {
+ if (isReleased) {
+ return true;
+ }
- return !buffersRead.isEmpty() && !buffersRead.peek().isBuffer();
+ if (numCreditsAvailable > 0) {
Review comment:
Perhaps change to
```
return !buffersRead.isEmpty() && (numCredit > 0 ||
!bufferReader.peek().isBuffer())
```
or
```
if (buffersRead.isEmpty()) {
return false;
}
return numCreditsAvailable > 0 || !buffersRead.peek().isBuffer();
```
to avoid duplicate condition ?
##########
File path:
flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/SortMergeResultPartitionReader.java
##########
@@ -0,0 +1,350 @@
+/*
+ * 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.flink.runtime.io.network.partition;
+
+import org.apache.flink.annotation.VisibleForTesting;
+import org.apache.flink.core.memory.MemorySegment;
+import org.apache.flink.runtime.io.disk.BatchShuffleReadBufferPool;
+import org.apache.flink.runtime.io.network.buffer.BufferRecycler;
+import org.apache.flink.util.IOUtils;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.annotation.concurrent.GuardedBy;
+
+import java.io.IOException;
+import java.nio.channels.FileChannel;
+import java.nio.file.Path;
+import java.nio.file.StandardOpenOption;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.List;
+import java.util.PriorityQueue;
+import java.util.Queue;
+import java.util.Set;
+import java.util.concurrent.Executor;
+import java.util.concurrent.TimeoutException;
+
+import static org.apache.flink.util.Preconditions.checkNotNull;
+import static org.apache.flink.util.Preconditions.checkState;
+
+/**
+ * Data reader for {@link SortMergeResultPartition} which can read data for
all downstream tasks
+ * consuming the corresponding {@link SortMergeResultPartition}. It always
tries to read shuffle
+ * data in order of file offset, which maximums the sequential read so can
improve the blocking
+ * shuffle performance.
+ */
+public class SortMergeResultPartitionReader implements Runnable,
BufferRecycler {
+
+ private static final Logger LOG =
LoggerFactory.getLogger(SortMergeResultPartitionReader.class);
+
+ /** Lock used to synchronize multi-thread access to thread-unsafe fields.
*/
+ private final Object lock;
+
+ /** Buffer pool from which to allocate buffers for shuffle data reading. */
+ private final BatchShuffleReadBufferPool bufferPool;
+
+ /** Executor to run the shuffle data reading task. */
+ private final Executor ioExecutor;
+
+ /** Maximum number of buffers can be allocated by this partition reader. */
+ private final int maxRequestedBuffers;
+
+ /** All failed subpartition readers to be released. */
+ @GuardedBy("lock")
+ private final Set<SortMergeSubpartitionReader> failedReaders = new
HashSet<>();
+
+ /** All readers waiting to read data of different subpartitions. */
+ @GuardedBy("lock")
+ private final Set<SortMergeSubpartitionReader> allReaders = new
HashSet<>();
+
+ /** File channel shared by all subpartitions to read data from. */
+ @GuardedBy("lock")
+ private FileChannel dataFileChannel;
+
+ /** File channel shared by all subpartitions to read index from. */
+ @GuardedBy("lock")
+ private FileChannel indexFileChannel;
+
+ /** Number of buffers already allocated and still not recycled by this
partition reader. */
+ @GuardedBy("lock")
+ private int numRequestedBuffers;
+
+ /**
+ * Whether the data reading task is currently running or not. This flag is
used when trying to
+ * submit the data reading task.
+ */
+ @GuardedBy("lock")
+ private boolean isRunning;
+
+ /** Whether this reader has been released or not. */
+ @GuardedBy("lock")
+ private boolean isReleased;
+
+ public SortMergeResultPartitionReader(
+ BatchShuffleReadBufferPool bufferPool, Executor ioExecutor, Object
lock) {
+ this.lock = checkNotNull(lock);
+ this.bufferPool = checkNotNull(bufferPool);
+ this.ioExecutor = checkNotNull(ioExecutor);
+ // one partition reader can consume at most 32M buffers for data read,
it is only an
+ // empirical value which can not be configured currently
+ this.maxRequestedBuffers = Math.max(1, 4 *
bufferPool.getNumBuffersPerRequest());
+
+ bufferPool.initialize();
+ }
+
+ @Override
+ public synchronized void run() {
+ Set<SortMergeSubpartitionReader> finishedReaders = new HashSet<>();
+ Queue<SortMergeSubpartitionReader> availableReaders =
getAvailableReaders();
+
+ Queue<MemorySegment> buffers = new ArrayDeque<>();
+ if (!availableReaders.isEmpty()) {
+ try {
+ buffers.addAll(bufferPool.requestBuffers());
+ } catch (Throwable throwable) {
+ // this can happen only when the buffer pool is destroyed or
buffer request timeout
+ if (!(throwable instanceof TimeoutException) ||
numRequestedBuffers <= 0) {
+ failSubpartitionReaders(availableReaders, throwable);
+ LOG.error("Failed to request buffers for data reading.",
throwable);
Review comment:
It seems we would still need to do some cleanup at last, but I still
tend to extract the cleanup into separate method and return directly here.
Perhaps as a whole we could change the logics here to be
```
xx = getAvailableReaders();
if (xx.isEmpty()) {
return;
}
// allocates buffers
try {
xxx
} catch (Exception e) {
recycleBuffers(buffers);
return;
}
.....
recycleBuffers();
removeFinishedAndFailedReaders(xx)
....
```
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