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https://issues.apache.org/jira/browse/HDFS-17593?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18090712#comment-18090712
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ASF GitHub Bot commented on HDFS-17593:
---------------------------------------
steveloughran commented on code in PR #8561:
URL: https://github.com/apache/hadoop/pull/8561#discussion_r3454963767
##########
hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java:
##########
@@ -378,6 +383,72 @@ public FSDataInputStream open(PathHandle fd, int
bufferSize)
return dfs.createWrappedInputStream(dfsis);
}
+ @Override
+ protected CompletableFuture<FSDataInputStream> openFileWithOptions(
+ final Path path,
+ final OpenFileParameters parameters) throws IOException {
+ AbstractFSBuilderImpl.rejectUnknownMandatoryKeys(
+ parameters.getMandatoryKeys(),
+ Options.OpenFileOptions.FS_OPTION_OPENFILE_STANDARD_OPTIONS,
+ "for " + path);
+ statistics.incrementReadOps(1);
+ storageStatistics.incrementOpCounter(OpType.OPEN);
+ final Path absF = fixRelativePart(path);
+ return LambdaUtils.eval(new CompletableFuture<>(), () -> {
+ LocatedBlocks locatedBlocks =
+ getLocatedBlocksFromStatus(parameters.getStatus());
+ final DFSInputStream dfsis;
+ if (locatedBlocks != null) {
+ dfsis = dfs.open(getPathName(absF), parameters.getBufferSize(),
+ verifyChecksum, locatedBlocks);
+ } else {
+ dfsis = dfs.open(getPathName(absF), parameters.getBufferSize(),
+ verifyChecksum);
+ }
+ return dfs.createWrappedInputStream(dfsis);
+ });
+ }
+
+ private static LocatedBlocks getLocatedBlocksFromStatus(FileStatus status) {
+ if (status instanceof HdfsLocatedFileStatus) {
+ return ((HdfsLocatedFileStatus) status).getLocatedBlocks();
+ }
+ return null;
+ }
+
+ /**
+ * Create a new input stream for the same file as an existing stream,
+ * reusing its cached block locations to avoid a NameNode RPC.
+ * The returned stream is independent (its own position, buffers, etc.)
+ * but shares the same block location metadata.
+ *
+ * @param existing an open input stream obtained from this filesystem
+ * @return a new independent input stream for the same file
+ * @throws IOException if the stream cannot be cloned
+ */
+ public FSDataInputStream cloneDataInputStream(FSDataInputStream existing)
+ throws IOException {
+ statistics.incrementReadOps(1);
+ storageStatistics.incrementOpCounter(OpType.OPEN);
+ InputStream wrapped = existing.getWrappedStream();
+ DFSInputStream dfsis;
+ if (wrapped instanceof DFSInputStream) {
+ dfsis = (DFSInputStream) wrapped;
+ } else if (wrapped instanceof org.apache.hadoop.crypto.CryptoInputStream) {
Review Comment:
you could use the java17 instanceof + variable declaration here as it's
worth the effort; intellij does the work for you
##########
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestOpenFileWithLocatedBlocks.java:
##########
@@ -0,0 +1,475 @@
+/**
+ * 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.hdfs;
+
+import static org.apache.hadoop.test.MetricsAsserts.assertCounter;
+import static org.apache.hadoop.test.MetricsAsserts.getMetrics;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.crypto.CryptoInputStream;
+import org.apache.hadoop.crypto.key.JavaKeyStoreProvider;
+import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystemTestHelper;
+import org.apache.hadoop.fs.LocatedFileStatus;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.RemoteIterator;
+import org.apache.hadoop.hdfs.client.CreateEncryptionZoneFlag;
+import org.apache.hadoop.hdfs.client.HdfsAdmin;
+import org.apache.hadoop.hdfs.protocol.HdfsLocatedFileStatus;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests that opening a file with pre-fetched block locations via the
+ * {@code openFile().withFileStatus()} builder API skips the NameNode RPC
+ * for block locations.
+ */
+public class TestOpenFileWithLocatedBlocks {
+ private static final String NN_METRICS = "NameNodeActivity";
+ private static final int BLOCK_SIZE = 1024;
+ private static final short REPLICATION = 1;
+ private static final String TEST_KEY = "test_key";
+ private static final EnumSet<CreateEncryptionZoneFlag> NO_TRASH =
+ EnumSet.of(CreateEncryptionZoneFlag.NO_TRASH);
+
+ private MiniDFSCluster cluster;
+ private DistributedFileSystem fs;
+ private Configuration conf;
+
+ @BeforeEach
+ public void setUp() throws IOException {
+ conf = new HdfsConfiguration();
+ conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, BLOCK_SIZE);
+ FileSystemTestHelper fsHelper = new FileSystemTestHelper();
+ File testRootDir = new File(fsHelper.getTestRootDir()).getAbsoluteFile();
+ conf.set(CommonConfigurationKeysPublic.HADOOP_SECURITY_KEY_PROVIDER_PATH,
+ JavaKeyStoreProvider.SCHEME_NAME + "://file" +
+ new Path(testRootDir.toString(), "test.jks").toUri());
+ cluster = new MiniDFSCluster.Builder(conf)
+ .numDataNodes(1)
+ .build();
+ cluster.waitActive();
+ fs = cluster.getFileSystem();
+ }
+
+ @AfterEach
+ public void tearDown() {
+ if (cluster != null) {
+ cluster.shutdown();
+ cluster = null;
+ }
+ }
+
+ private Path createFile(String name, byte[] data) throws IOException {
Review Comment:
org.apache.hadoop.fs.contract.ContractTestUtils do this and the readfully
for you
##########
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestOpenFileWithLocatedBlocks.java:
##########
@@ -0,0 +1,475 @@
+/**
+ * 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.hdfs;
+
+import static org.apache.hadoop.test.MetricsAsserts.assertCounter;
+import static org.apache.hadoop.test.MetricsAsserts.getMetrics;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertInstanceOf;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.Random;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.crypto.CryptoInputStream;
+import org.apache.hadoop.crypto.key.JavaKeyStoreProvider;
+import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
+import org.apache.hadoop.fs.FSDataInputStream;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystemTestHelper;
+import org.apache.hadoop.fs.LocatedFileStatus;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.RemoteIterator;
+import org.apache.hadoop.hdfs.client.CreateEncryptionZoneFlag;
+import org.apache.hadoop.hdfs.client.HdfsAdmin;
+import org.apache.hadoop.hdfs.protocol.HdfsLocatedFileStatus;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests that opening a file with pre-fetched block locations via the
+ * {@code openFile().withFileStatus()} builder API skips the NameNode RPC
+ * for block locations.
+ */
+public class TestOpenFileWithLocatedBlocks {
+ private static final String NN_METRICS = "NameNodeActivity";
+ private static final int BLOCK_SIZE = 1024;
+ private static final short REPLICATION = 1;
+ private static final String TEST_KEY = "test_key";
+ private static final EnumSet<CreateEncryptionZoneFlag> NO_TRASH =
+ EnumSet.of(CreateEncryptionZoneFlag.NO_TRASH);
+
+ private MiniDFSCluster cluster;
+ private DistributedFileSystem fs;
+ private Configuration conf;
+
+ @BeforeEach
+ public void setUp() throws IOException {
+ conf = new HdfsConfiguration();
+ conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, BLOCK_SIZE);
+ FileSystemTestHelper fsHelper = new FileSystemTestHelper();
+ File testRootDir = new File(fsHelper.getTestRootDir()).getAbsoluteFile();
+ conf.set(CommonConfigurationKeysPublic.HADOOP_SECURITY_KEY_PROVIDER_PATH,
+ JavaKeyStoreProvider.SCHEME_NAME + "://file" +
+ new Path(testRootDir.toString(), "test.jks").toUri());
+ cluster = new MiniDFSCluster.Builder(conf)
Review Comment:
hdfs tests must do it per test suite, so tests run faster.
> Allow setting block locations when opening streams
> --------------------------------------------------
>
> Key: HDFS-17593
> URL: https://issues.apache.org/jira/browse/HDFS-17593
> Project: Hadoop HDFS
> Issue Type: Improvement
> Reporter: Csaba Ringhofer
> Priority: Major
> Labels: pull-request-available
>
> The HDFS client seems to always get block locations from the namenode when
> opening a file:
> https://github.com/apache/hadoop/blob/4525c7e35ea22d7a6350b8af10eb8d2ff68376e7/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSClient.java#L1099
> This leads to unnecessary RPCs in Apache Impala when doing reads, as the
> block locations are cached globally and the executors already have a good
> guess about the block locations when opening a stream. Unless the cached
> block locations are stale ideally no RPC should be made to the namenode.
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