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https://issues.apache.org/jira/browse/FLINK-8360?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16365585#comment-16365585
]
ASF GitHub Bot commented on FLINK-8360:
---------------------------------------
Github user tillrohrmann commented on a diff in the pull request:
https://github.com/apache/flink/pull/5239#discussion_r168475165
--- Diff:
flink-runtime/src/main/java/org/apache/flink/runtime/state/CheckpointStreamWithResultProvider.java
---
@@ -0,0 +1,175 @@
+/*
+ * 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.state;
+
+import org.apache.flink.core.fs.Path;
+import
org.apache.flink.runtime.state.filesystem.FixFileFsStateOutputStream;
+import org.apache.flink.util.ExceptionUtils;
+import org.apache.flink.util.Preconditions;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.Closeable;
+import java.io.File;
+import java.io.IOException;
+
+/**
+ * Interface that provides access to a CheckpointStateOutputStream and a
method to provide the {@link SnapshotResult}.
+ * This abstracts from different ways that a result is obtained from
checkpoint output streams.
+ */
+public interface CheckpointStreamWithResultProvider extends Closeable {
+
+ SnapshotResult<KeyedStateHandle> closeAndFinalizeCheckpointStreamResult(
+ KeyGroupRangeOffsets kgOffs) throws IOException;
+
+ CheckpointStreamFactory.CheckpointStateOutputStream
getCheckpointOutputStream();
+
+ @Override
+ default void close() throws IOException {
+ CheckpointStreamFactory.CheckpointStateOutputStream
outputStream = getCheckpointOutputStream();
+ if (outputStream != null) {
+ outputStream.close();
+ }
+ }
+
+ /**
+ * Implementation of {@link CheckpointStreamWithResultProvider} that
only creates the
+ * primary/remote/jm-owned state.
+ */
+ class PrimaryStreamOnly implements CheckpointStreamWithResultProvider {
+
+ private final
CheckpointStreamFactory.CheckpointStateOutputStream outputStream;
+
+ public
PrimaryStreamOnly(CheckpointStreamFactory.CheckpointStateOutputStream
outputStream) {
+ this.outputStream =
Preconditions.checkNotNull(outputStream);
+ }
+
+ @Override
+ public SnapshotResult<KeyedStateHandle>
closeAndFinalizeCheckpointStreamResult(
+ KeyGroupRangeOffsets kgOffs) throws IOException {
+
+ StreamStateHandle streamStateHandle =
outputStream.closeAndGetHandle();
+ KeyGroupsStateHandle primaryStateHandle = new
KeyGroupsStateHandle(kgOffs, streamStateHandle);
+ return new SnapshotResult<>(primaryStateHandle, null);
+ }
+
+ @Override
+ public CheckpointStreamFactory.CheckpointStateOutputStream
getCheckpointOutputStream() {
+ return outputStream;
+ }
+ }
+
+ /**
+ * Implementation of {@link CheckpointStreamWithResultProvider} that
creates both, the
+ * primary/remote/jm-owned state and the secondary/local/tm-owned state.
+ */
+ class PrimaryAndSecondaryStream implements
CheckpointStreamWithResultProvider {
+
+ private static final Logger LOG =
LoggerFactory.getLogger(PrimaryAndSecondaryStream.class);
+
+ private final DuplicatingCheckpointOutputStream outputStream;
+
+ public
PrimaryAndSecondaryStream(DuplicatingCheckpointOutputStream outputStream) {
+ this.outputStream =
Preconditions.checkNotNull(outputStream);
+ }
+
+ @Override
+ public SnapshotResult<KeyedStateHandle>
closeAndFinalizeCheckpointStreamResult(
+ KeyGroupRangeOffsets offsets) throws IOException {
+
+ final StreamStateHandle primaryStreamStateHandle;
+
+ try {
+ primaryStreamStateHandle =
outputStream.closeAndGetPrimaryHandle();
+ } catch (IOException primaryEx) {
+ try {
+ outputStream.close();
+ } catch (IOException closeEx) {
+ primaryEx =
ExceptionUtils.firstOrSuppressed(closeEx, primaryEx);
+ }
+ throw primaryEx;
+ }
+
+ StreamStateHandle secondaryStreamStateHandle = null;
+
+ try {
+ secondaryStreamStateHandle =
outputStream.closeAndGetSecondaryHandle();
+ } catch (IOException secondaryEx) {
+ LOG.warn("Exception from secondary/local
checkpoint stream.", secondaryEx);
+ }
+
+ if (primaryStreamStateHandle != null) {
+
+ final KeyGroupsStateHandle
primaryKeyGroupsStateHandle =
+ new KeyGroupsStateHandle(offsets,
primaryStreamStateHandle);
+
+ final KeyGroupsStateHandle
secondaryKeyGroupsStateHandle = secondaryStreamStateHandle != null ?
+ new KeyGroupsStateHandle(offsets,
secondaryStreamStateHandle) :
+ null;
+
+ return new
SnapshotResult<>(primaryKeyGroupsStateHandle, secondaryKeyGroupsStateHandle);
+ }
+
+ return null;
+ }
+
+ @Override
+ public DuplicatingCheckpointOutputStream
getCheckpointOutputStream() {
+ return outputStream;
+ }
+ }
+
+ class Factory {
+
+ private static final Logger LOG =
LoggerFactory.getLogger(PrimaryAndSecondaryStream.class);
+
+ public CheckpointStreamWithResultProvider create(
+ long checkpointId,
+ long timestamp,
+ CheckpointStreamFactory primaryStreamFactory,
+ LocalRecoveryDirectoryProvider
secondaryStreamDirProvider) throws Exception {
+
+ CheckpointStreamFactory.CheckpointStateOutputStream
primaryOut =
+
primaryStreamFactory.createCheckpointStateOutputStream(checkpointId, timestamp);
+
+ CheckpointStreamFactory.CheckpointStateOutputStream
secondaryOut;
+
+ if (secondaryStreamDirProvider != null) {
+ try {
+ File currentLocalRecoveryRoot =
secondaryStreamDirProvider.nextRootDirectory();
+ File outFile = new File(
+ currentLocalRecoveryRoot,
+
secondaryStreamDirProvider.specificFileForCheckpointId(checkpointId));
+ Path outPath = new
Path(outFile.toURI());
+ secondaryOut = new
FixFileFsStateOutputStream(outPath.getFileSystem(), outPath);
+ final DuplicatingCheckpointOutputStream
effectiveOutStream =
+ new
DuplicatingCheckpointOutputStream(primaryOut, secondaryOut);
+
+ return new
CheckpointStreamWithResultProvider.PrimaryAndSecondaryStream(effectiveOutStream);
--- End diff --
Wouldn't it make more sense to pass in the primary and secondary stream
given the method name? Internally one would then create the
`DuplicatingCheckpointOutputStream`.
> Implement task-local state recovery
> -----------------------------------
>
> Key: FLINK-8360
> URL: https://issues.apache.org/jira/browse/FLINK-8360
> Project: Flink
> Issue Type: New Feature
> Components: State Backends, Checkpointing
> Reporter: Stefan Richter
> Assignee: Stefan Richter
> Priority: Major
> Fix For: 1.5.0
>
>
> This issue tracks the development of recovery from task-local state. The main
> idea is to have a secondary, local copy of the checkpointed state, while
> there is still a primary copy in DFS that we report to the checkpoint
> coordinator.
> Recovery can attempt to restore from the secondary local copy, if available,
> to save network bandwidth. This requires that the assignment from tasks to
> slots is as sticky is possible.
> For starters, we will implement this feature for all managed keyed states and
> can easily enhance it to all other state types (e.g. operator state) later.
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