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Posted to issues@flink.apache.org by GitBox <gi...@apache.org> on 2020/10/19 14:58:50 UTC
[GitHub] [flink] rkhachatryan commented on a change in pull request #13648: [FLINK-19632] Introduce a new ResultPartitionType for Approximate Local Recovery
rkhachatryan commented on a change in pull request #13648:
URL: https://github.com/apache/flink/pull/13648#discussion_r507745730
##########
File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/ResultPartitionType.java
##########
@@ -71,7 +71,17 @@
* <p>For batch jobs, it will be best to keep this unlimited ({@link #PIPELINED}) since there are
* no checkpoint barriers.
*/
- PIPELINED_BOUNDED(true, true, true, false);
+ PIPELINED_BOUNDED(true, true, true, false),
+
+ /**
+ * Pipelined partitions with a bounded (local) buffer pool to support downstream task to
+ * continue consuming data after reconnection in Approximate Local-Recovery.
+ *
+ * <p>Pipelined results can be consumed only once by a single consumer at one time.
+ * {@link #PIPELINED_APPROXIMATE} is different from {@link #PIPELINED_BOUNDED} in that
+ * {@link #PIPELINED_APPROXIMATE} is not decomposed automatically after consumption.
+ */
+ PIPELINED_APPROXIMATE(true, true, true, true);
Review comment:
Can you please explain why this partition type is bounded?
##########
File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/PipelinedApproximateSubpartition.java
##########
@@ -0,0 +1,105 @@
+/*
+ * 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.runtime.io.network.buffer.Buffer;
+import org.apache.flink.runtime.io.network.buffer.BufferConsumerWithPartialRecordLength;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.apache.flink.util.Preconditions.checkState;
+
+/**
+ * A pipelined in-memory only subpartition, which allows to reconnecting after failure.
+ * Only one view is allowed at a time to read teh subpartition.
+ */
+public class PipelinedApproximateSubpartition extends PipelinedSubpartition {
+
+ private static final Logger LOG = LoggerFactory.getLogger(PipelinedApproximateSubpartition.class);
+
+ private boolean isPartialBuffer = false;
+
+ PipelinedApproximateSubpartition(int index, ResultPartition parent) {
+ super(index, parent);
+ }
+
+ @Override
+ public PipelinedSubpartitionView createReadView(BufferAvailabilityListener availabilityListener) {
+ synchronized (buffers) {
+ checkState(!isReleased);
+
+ // if the view is not released yet
+ if (readView != null) {
+ LOG.info("{} ReadView for Subpartition {} of {} has not been released!",
Review comment:
I think this message should mention that a new view is being created.
##########
File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/PipelinedApproximateSubpartition.java
##########
@@ -0,0 +1,105 @@
+/*
+ * 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.runtime.io.network.buffer.Buffer;
+import org.apache.flink.runtime.io.network.buffer.BufferConsumerWithPartialRecordLength;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.apache.flink.util.Preconditions.checkState;
+
+/**
+ * A pipelined in-memory only subpartition, which allows to reconnecting after failure.
+ * Only one view is allowed at a time to read teh subpartition.
+ */
+public class PipelinedApproximateSubpartition extends PipelinedSubpartition {
+
+ private static final Logger LOG = LoggerFactory.getLogger(PipelinedApproximateSubpartition.class);
+
+ private boolean isPartialBuffer = false;
+
+ PipelinedApproximateSubpartition(int index, ResultPartition parent) {
+ super(index, parent);
+ }
+
+ @Override
+ public PipelinedSubpartitionView createReadView(BufferAvailabilityListener availabilityListener) {
+ synchronized (buffers) {
+ checkState(!isReleased);
+
+ // if the view is not released yet
+ if (readView != null) {
+ LOG.info("{} ReadView for Subpartition {} of {} has not been released!",
+ parent.getOwningTaskName(), getSubPartitionIndex(), parent.getPartitionId());
+ releaseView();
+ }
+
+ LOG.debug("{}: Creating read view for subpartition {} of partition {}.",
+ parent.getOwningTaskName(), getSubPartitionIndex(), parent.getPartitionId());
+
+ readView = new PipelinedApproximateSubpartitionView(this, availabilityListener);
+ }
+
+ return readView;
+ }
+
+ @Override
+ Buffer buildSliceBuffer(BufferConsumerWithPartialRecordLength buffer) {
+ if (isPartialBuffer) {
+ isPartialBuffer = !buffer.cleanupPartialRecord();
+ }
+
+ return buffer.build();
+ }
+
+ void releaseView() {
+ LOG.info("Releasing view of subpartition {} of {}.", getSubPartitionIndex(), parent.getPartitionId());
+ readView = null;
Review comment:
The writes in this method should be done under a lock, right?
But I'm not sure that all execution paths do acquire this lock.
Should we add `synchronized (buffers)` or `checkState(Thread.holdsLock)`?
##########
File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/PipelinedApproximateSubpartition.java
##########
@@ -0,0 +1,105 @@
+/*
+ * 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.runtime.io.network.buffer.Buffer;
+import org.apache.flink.runtime.io.network.buffer.BufferConsumerWithPartialRecordLength;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.apache.flink.util.Preconditions.checkState;
+
+/**
+ * A pipelined in-memory only subpartition, which allows to reconnecting after failure.
+ * Only one view is allowed at a time to read teh subpartition.
+ */
+public class PipelinedApproximateSubpartition extends PipelinedSubpartition {
+
+ private static final Logger LOG = LoggerFactory.getLogger(PipelinedApproximateSubpartition.class);
+
+ private boolean isPartialBuffer = false;
+
+ PipelinedApproximateSubpartition(int index, ResultPartition parent) {
+ super(index, parent);
+ }
+
+ @Override
+ public PipelinedSubpartitionView createReadView(BufferAvailabilityListener availabilityListener) {
+ synchronized (buffers) {
+ checkState(!isReleased);
+
+ // if the view is not released yet
+ if (readView != null) {
+ LOG.info("{} ReadView for Subpartition {} of {} has not been released!",
+ parent.getOwningTaskName(), getSubPartitionIndex(), parent.getPartitionId());
+ releaseView();
+ }
+
+ LOG.debug("{}: Creating read view for subpartition {} of partition {}.",
+ parent.getOwningTaskName(), getSubPartitionIndex(), parent.getPartitionId());
+
+ readView = new PipelinedApproximateSubpartitionView(this, availabilityListener);
+ }
+
+ return readView;
+ }
+
+ @Override
+ Buffer buildSliceBuffer(BufferConsumerWithPartialRecordLength buffer) {
+ if (isPartialBuffer) {
+ isPartialBuffer = !buffer.cleanupPartialRecord();
+ }
+
+ return buffer.build();
+ }
+
+ void releaseView() {
+ LOG.info("Releasing view of subpartition {} of {}.", getSubPartitionIndex(), parent.getPartitionId());
+ readView = null;
+ isPartialBuffer = true;
+ isBlockedByCheckpoint = false;
+ sequenceNumber = 0;
+ }
+
+ @Override
+ public String toString() {
Review comment:
I couldn't find any differences from `super.toString` other than class name.
Can we just replace in super `"PipelinedSubpartition` with `getSiimpleClassName` instead of overriding?
ditto: view
##########
File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/PipelinedApproximateSubpartition.java
##########
@@ -0,0 +1,105 @@
+/*
+ * 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.runtime.io.network.buffer.Buffer;
+import org.apache.flink.runtime.io.network.buffer.BufferConsumerWithPartialRecordLength;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.apache.flink.util.Preconditions.checkState;
+
+/**
+ * A pipelined in-memory only subpartition, which allows to reconnecting after failure.
+ * Only one view is allowed at a time to read teh subpartition.
+ */
+public class PipelinedApproximateSubpartition extends PipelinedSubpartition {
+
+ private static final Logger LOG = LoggerFactory.getLogger(PipelinedApproximateSubpartition.class);
+
+ private boolean isPartialBuffer = false;
+
+ PipelinedApproximateSubpartition(int index, ResultPartition parent) {
+ super(index, parent);
+ }
+
+ @Override
+ public PipelinedSubpartitionView createReadView(BufferAvailabilityListener availabilityListener) {
+ synchronized (buffers) {
+ checkState(!isReleased);
+
+ // if the view is not released yet
+ if (readView != null) {
+ LOG.info("{} ReadView for Subpartition {} of {} has not been released!",
+ parent.getOwningTaskName(), getSubPartitionIndex(), parent.getPartitionId());
+ releaseView();
+ }
+
+ LOG.debug("{}: Creating read view for subpartition {} of partition {}.",
+ parent.getOwningTaskName(), getSubPartitionIndex(), parent.getPartitionId());
+
+ readView = new PipelinedApproximateSubpartitionView(this, availabilityListener);
+ }
+
+ return readView;
+ }
+
+ @Override
+ Buffer buildSliceBuffer(BufferConsumerWithPartialRecordLength buffer) {
+ if (isPartialBuffer) {
+ isPartialBuffer = !buffer.cleanupPartialRecord();
+ }
+
+ return buffer.build();
Review comment:
nit: `super.buildSliceBuffer` ?
##########
File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/PipelinedApproximateSubpartitionView.java
##########
@@ -0,0 +1,48 @@
+/*
+ * 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 static org.apache.flink.util.Preconditions.checkState;
+
+/**
+ * View over a pipelined in-memory only subpartition allowing reconnecting.
+ */
+public class PipelinedApproximateSubpartitionView extends PipelinedSubpartitionView {
+
+ PipelinedApproximateSubpartitionView(PipelinedApproximateSubpartition parent, BufferAvailabilityListener listener) {
+ super(parent, listener);
+ }
+
+ @Override
+ public void releaseAllResources() {
Review comment:
I think this method is called not only upon downstream RPC, but also on task shutdown and other cases.
If so, completely skipping of `super.releaseAllResources` can lead to resource leaks in those cases.
WDYT?
##########
File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/PipelinedSubpartition.java
##########
@@ -259,9 +260,10 @@ BufferAndBacklog pollBuffer() {
}
while (!buffers.isEmpty()) {
- BufferConsumer bufferConsumer = buffers.peek().getBufferConsumer();
+ BufferConsumerWithPartialRecordLength bufferConsumerWithPartialRecordLength = buffers.peek();
+ BufferConsumer bufferConsumer = requireNonNull(bufferConsumerWithPartialRecordLength).getBufferConsumer();
Review comment:
I think there is no point in adding explicit `requireNonNull` just before dereferencing it.
##########
File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/PipelinedApproximateSubpartition.java
##########
@@ -0,0 +1,105 @@
+/*
+ * 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.runtime.io.network.buffer.Buffer;
+import org.apache.flink.runtime.io.network.buffer.BufferConsumerWithPartialRecordLength;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.apache.flink.util.Preconditions.checkState;
+
+/**
+ * A pipelined in-memory only subpartition, which allows to reconnecting after failure.
+ * Only one view is allowed at a time to read teh subpartition.
+ */
+public class PipelinedApproximateSubpartition extends PipelinedSubpartition {
+
+ private static final Logger LOG = LoggerFactory.getLogger(PipelinedApproximateSubpartition.class);
+
+ private boolean isPartialBuffer = false;
+
+ PipelinedApproximateSubpartition(int index, ResultPartition parent) {
+ super(index, parent);
+ }
+
+ @Override
+ public PipelinedSubpartitionView createReadView(BufferAvailabilityListener availabilityListener) {
+ synchronized (buffers) {
+ checkState(!isReleased);
+
+ // if the view is not released yet
+ if (readView != null) {
+ LOG.info("{} ReadView for Subpartition {} of {} has not been released!",
+ parent.getOwningTaskName(), getSubPartitionIndex(), parent.getPartitionId());
+ releaseView();
+ }
+
+ LOG.debug("{}: Creating read view for subpartition {} of partition {}.",
+ parent.getOwningTaskName(), getSubPartitionIndex(), parent.getPartitionId());
+
+ readView = new PipelinedApproximateSubpartitionView(this, availabilityListener);
+ }
+
+ return readView;
+ }
+
+ @Override
+ Buffer buildSliceBuffer(BufferConsumerWithPartialRecordLength buffer) {
+ if (isPartialBuffer) {
+ isPartialBuffer = !buffer.cleanupPartialRecord();
+ }
+
+ return buffer.build();
+ }
+
+ void releaseView() {
+ LOG.info("Releasing view of subpartition {} of {}.", getSubPartitionIndex(), parent.getPartitionId());
+ readView = null;
Review comment:
I'm concerned about a potential race condition here (even with `synchronized` added).
Consider a case:
Thread1: call `subpartition.createReadView()` - create `view1`
Thread2: obtain a reference to `view1`
Thread1: call `subpartition.createReadView()` - create `view2`
Thread2: call `view1.releaseAllResources` <-- nulls out subpartition.readView; `view2` is now corrupt?
WDYT?
##########
File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/PipelinedApproximateSubpartition.java
##########
@@ -0,0 +1,105 @@
+/*
+ * 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.runtime.io.network.buffer.Buffer;
+import org.apache.flink.runtime.io.network.buffer.BufferConsumerWithPartialRecordLength;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static org.apache.flink.util.Preconditions.checkState;
+
+/**
+ * A pipelined in-memory only subpartition, which allows to reconnecting after failure.
+ * Only one view is allowed at a time to read teh subpartition.
+ */
+public class PipelinedApproximateSubpartition extends PipelinedSubpartition {
+
+ private static final Logger LOG = LoggerFactory.getLogger(PipelinedApproximateSubpartition.class);
+
+ private boolean isPartialBuffer = false;
+
+ PipelinedApproximateSubpartition(int index, ResultPartition parent) {
+ super(index, parent);
+ }
+
+ @Override
+ public PipelinedSubpartitionView createReadView(BufferAvailabilityListener availabilityListener) {
+ synchronized (buffers) {
+ checkState(!isReleased);
+
+ // if the view is not released yet
+ if (readView != null) {
+ LOG.info("{} ReadView for Subpartition {} of {} has not been released!",
+ parent.getOwningTaskName(), getSubPartitionIndex(), parent.getPartitionId());
+ releaseView();
+ }
+
+ LOG.debug("{}: Creating read view for subpartition {} of partition {}.",
+ parent.getOwningTaskName(), getSubPartitionIndex(), parent.getPartitionId());
+
+ readView = new PipelinedApproximateSubpartitionView(this, availabilityListener);
+ }
+
+ return readView;
+ }
+
+ @Override
+ Buffer buildSliceBuffer(BufferConsumerWithPartialRecordLength buffer) {
+ if (isPartialBuffer) {
+ isPartialBuffer = !buffer.cleanupPartialRecord();
+ }
+
+ return buffer.build();
+ }
+
+ void releaseView() {
+ LOG.info("Releasing view of subpartition {} of {}.", getSubPartitionIndex(), parent.getPartitionId());
+ readView = null;
+ isPartialBuffer = true;
Review comment:
The name `isPartialBuffer` is a bit misleading to me because it implies that partial buffer was emitted.
But in fact, this field reflects that the view was released.
How about `isPartialBufferCleanupRequired`?
##########
File path: flink-runtime/src/main/java/org/apache/flink/runtime/io/network/partition/ResultPartitionFactory.java
##########
@@ -130,8 +132,15 @@ public ResultPartition create(
bufferCompressor,
bufferPoolFactory);
+ BiFunction<Integer, PipelinedResultPartition, PipelinedSubpartition> factory;
+ if (type == ResultPartitionType.PIPELINED_APPROXIMATE) {
+ factory = PipelinedApproximateSubpartition::new;
+ } else {
+ factory = PipelinedSubpartition::new;
+ }
+
Review comment:
nit: I'd prefer this simple ternary if in a loop:
```
for (int i = 0; i < subpartitions.length; i++) {
subpartitions[i] = type == ResultPartitionType.PIPELINED_APPROXIMATE ?
new PipelinedApproximateSubpartition(i, pipelinedPartition) :
new PipelinedSubpartition(i, pipelinedPartition);
}
```
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