Apache
/
hadoop
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

HADOOP-16202. Enhanced openFile(): hadoop-common changes. (#2584/1) 

This defines standard option and values for the
openFile() builder API for opening a file:

fs.option.openfile.read.policy
 A list of the desired read policy, in preferred order.
 standard values are
 adaptive, default, random, sequential, vector, whole-file

fs.option.openfile.length
 How long the file is.

fs.option.openfile.split.start
 start of a task's split

fs.option.openfile.split.end
 end of a task's split

These can be used by filesystem connectors to optimize their
reading of the source file, including but not limited to
* skipping existence/length probes when opening a file
* choosing a policy for prefetching/caching data

The hadoop shell commands which read files all declare "whole-file"
and "sequential", as appropriate.

Contributed by Steve Loughran.

Change-Id: Ia290f79ea7973ce8713d4f90f1315b24d7a23da1
This commit is contained in:
Steve Loughran 2022-04-24 17:03:59 +01:00
parent 77eea7a11b
commit 75950e47e7
No known key found for this signature in database
GPG Key ID: D22CF846DBB162A0
36 changed files with 1321 additions and 261 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AvroFSInput.java
View File

@ -25,6 +25,10 @@ import org.apache.avro.file.SeekableInput;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL;
import static org.apache.hadoop.util.functional.FutureIO.awaitFuture;
/** Adapts an {@link FSDataInputStream} to Avro's SeekableInput interface. */
@InterfaceAudience.Public
@InterfaceStability.Stable
@ -42,7 +46,12 @@ public class AvroFSInput implements Closeable, SeekableInput {
public AvroFSInput(final FileContext fc, final Path p) throws IOException {
FileStatus status = fc.getFileStatus(p);
this.len = status.getLen();
this.stream = fc.open(p);
this.stream = awaitFuture(fc.openFile(p)
.opt(FS_OPTION_OPENFILE_READ_POLICY,
FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL)
.withFileStatus(status)
.build());
fc.open(p);
}
@Override

4
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/ChecksumFileSystem.java
View File

@ -24,7 +24,6 @@ import java.io.IOException;
import java.io.InputStream;
import java.nio.channels.ClosedChannelException;
import java.util.Arrays;
import java.util.Collections;
import java.util.EnumSet;
import java.util.List;
import java.util.concurrent.CompletableFuture;
@ -45,6 +44,7 @@ import org.apache.hadoop.util.DataChecksum;
import org.apache.hadoop.util.LambdaUtils;
import org.apache.hadoop.util.Progressable;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_STANDARD_OPTIONS;
import static org.apache.hadoop.fs.impl.PathCapabilitiesSupport.validatePathCapabilityArgs;
import static org.apache.hadoop.fs.impl.StoreImplementationUtils.isProbeForSyncable;
@ -889,7 +889,7 @@ public abstract class ChecksumFileSystem extends FilterFileSystem {
final OpenFileParameters parameters) throws IOException {
AbstractFSBuilderImpl.rejectUnknownMandatoryKeys(
parameters.getMandatoryKeys(),
Collections.emptySet(),
FS_OPTION_OPENFILE_STANDARD_OPTIONS,
"for " + path);
return LambdaUtils.eval(
new CompletableFuture<>(),

14
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FSBuilder.java
View File

@ -61,6 +61,13 @@ public interface FSBuilder<S, B extends FSBuilder<S, B>> {
*/
B opt(@Nonnull String key, float value);
/**
* Set optional long parameter for the Builder.
*
* @see #opt(String, String)
*/
B opt(@Nonnull String key, long value);
/**
* Set optional double parameter for the Builder.
*
@ -104,6 +111,13 @@ public interface FSBuilder<S, B extends FSBuilder<S, B>> {
*/
B must(@Nonnull String key, float value);
/**
* Set mandatory long option.
*
* @see #must(String, String)
*/
B must(@Nonnull String key, long value);
/**
* Set mandatory double option.
*

18
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileContext.java
View File

@ -71,7 +71,12 @@ import org.apache.hadoop.tracing.Tracer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_BUFFER_SIZE;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_LENGTH;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE;
import static org.apache.hadoop.fs.impl.PathCapabilitiesSupport.validatePathCapabilityArgs;
import static org.apache.hadoop.util.functional.FutureIO.awaitFuture;
/**
* The FileContext class provides an interface for users of the Hadoop
@ -2204,7 +2209,12 @@ public class FileContext implements PathCapabilities {
EnumSet<CreateFlag> createFlag = overwrite ? EnumSet.of(
CreateFlag.CREATE, CreateFlag.OVERWRITE) :
EnumSet.of(CreateFlag.CREATE);
InputStream in = open(qSrc);
InputStream in = awaitFuture(openFile(qSrc)
.opt(FS_OPTION_OPENFILE_READ_POLICY,
FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE)
.opt(FS_OPTION_OPENFILE_LENGTH,
fs.getLen()) // file length hint for object stores
.build());
try (OutputStream out = create(qDst, createFlag)) {
IOUtils.copyBytes(in, out, conf, true);
} finally {
@ -2936,9 +2946,11 @@ public class FileContext implements PathCapabilities {
final Path absF = fixRelativePart(getPath());
OpenFileParameters parameters = new OpenFileParameters()
.withMandatoryKeys(getMandatoryKeys())
.withOptionalKeys(getOptionalKeys())
.withOptions(getOptions())
.withBufferSize(getBufferSize())
.withStatus(getStatus());
.withStatus(getStatus())
.withBufferSize(
getOptions().getInt(FS_OPTION_OPENFILE_BUFFER_SIZE, getBufferSize()));
return new FSLinkResolver<CompletableFuture<FSDataInputStream>>() {
@Override
public CompletableFuture<FSDataInputStream> next(

13
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileSystem.java
View File

@ -91,7 +91,8 @@ import org.apache.hadoop.thirdparty.com.google.common.annotations.VisibleForTest
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.hadoop.thirdparty.com.google.common.base.Preconditions.checkArgument;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_BUFFER_SIZE;
import static org.apache.hadoop.util.Preconditions.checkArgument;
import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.*;
import static org.apache.hadoop.fs.impl.PathCapabilitiesSupport.validatePathCapabilityArgs;
@ -4626,7 +4627,7 @@ public abstract class FileSystem extends Configured
final OpenFileParameters parameters) throws IOException {
AbstractFSBuilderImpl.rejectUnknownMandatoryKeys(
parameters.getMandatoryKeys(),
Collections.emptySet(),
Options.OpenFileOptions.FS_OPTION_OPENFILE_STANDARD_OPTIONS,
"for " + path);
return LambdaUtils.eval(
new CompletableFuture<>(), () ->
@ -4654,7 +4655,7 @@ public abstract class FileSystem extends Configured
final OpenFileParameters parameters) throws IOException {
AbstractFSBuilderImpl.rejectUnknownMandatoryKeys(
parameters.getMandatoryKeys(),
Collections.emptySet(), "");
Options.OpenFileOptions.FS_OPTION_OPENFILE_STANDARD_OPTIONS, "");
CompletableFuture<FSDataInputStream> result = new CompletableFuture<>();
try {
result.complete(open(pathHandle, parameters.getBufferSize()));
@ -4761,9 +4762,11 @@ public abstract class FileSystem extends Configured
Optional<Path> optionalPath = getOptionalPath();
OpenFileParameters parameters = new OpenFileParameters()
.withMandatoryKeys(getMandatoryKeys())
.withOptionalKeys(getOptionalKeys())
.withOptions(getOptions())
.withBufferSize(getBufferSize())
.withStatus(super.getStatus()); // explicit to avoid IDE warnings
.withStatus(super.getStatus())
.withBufferSize(
getOptions().getInt(FS_OPTION_OPENFILE_BUFFER_SIZE, getBufferSize()));
if(optionalPath.isPresent()) {
return getFS().openFileWithOptions(optionalPath.get(),
parameters);

61
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FileUtil.java
View File

@ -76,6 +76,11 @@ import org.apache.hadoop.util.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_LENGTH;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE;
import static org.apache.hadoop.util.functional.FutureIO.awaitFuture;
/**
* A collection of file-processing util methods
*/
@ -395,7 +400,32 @@ public class FileUtil {
return copy(srcFS, fileStatus, dstFS, dst, deleteSource, overwrite, conf);
}
/** Copy files between FileSystems. */
/**
* Copy a file/directory tree within/between filesystems.
* <p></p>
* returns true if the operation succeeded. When deleteSource is true,
* this means "after the copy, delete(source) returned true"
* If the destination is a directory, and mkdirs (dest) fails,
* the operation will return false rather than raise any exception.
* <p></p>
* The overwrite flag is about overwriting files; it has no effect about
* handing an attempt to copy a file atop a directory (expect an IOException),
* or a directory over a path which contains a file (mkdir will fail, so
* "false").
* <p></p>
* The operation is recursive, and the deleteSource operation takes place
* as each subdirectory is copied. Therefore, if an operation fails partway
* through, the source tree may be partially deleted.
* @param srcFS source filesystem
* @param srcStatus status of source
* @param dstFS destination filesystem
* @param dst path of source
* @param deleteSource delete the source?
* @param overwrite overwrite files at destination?
* @param conf configuration to use when opening files
* @return true if the operation succeeded.
* @throws IOException failure
*/
public static boolean copy(FileSystem srcFS, FileStatus srcStatus,
FileSystem dstFS, Path dst,
boolean deleteSource,
@ -408,22 +438,27 @@ public class FileUtil {
if (!dstFS.mkdirs(dst)) {
return false;
}
FileStatus contents[] = srcFS.listStatus(src);
for (int i = 0; i < contents.length; i++) {
copy(srcFS, contents[i], dstFS,
new Path(dst, contents[i].getPath().getName()),
deleteSource, overwrite, conf);
RemoteIterator<FileStatus> contents = srcFS.listStatusIterator(src);
while (contents.hasNext()) {
FileStatus next = contents.next();
copy(srcFS, next, dstFS,
new Path(dst, next.getPath().getName()),
deleteSource, overwrite, conf);
}
} else {
InputStream in=null;
InputStream in = null;
OutputStream out = null;
try {
in = srcFS.open(src);
in = awaitFuture(srcFS.openFile(src)
.opt(FS_OPTION_OPENFILE_READ_POLICY,
FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE)
.opt(FS_OPTION_OPENFILE_LENGTH,
srcStatus.getLen()) // file length hint for object stores
.build());
out = dstFS.create(dst, overwrite);
IOUtils.copyBytes(in, out, conf, true);
} catch (IOException e) {
IOUtils.closeStream(out);
IOUtils.closeStream(in);
IOUtils.cleanupWithLogger(LOG, in, out);
throw e;
}
}
@ -502,7 +537,11 @@ public class FileUtil {
deleteSource, conf);
}
} else {
InputStream in = srcFS.open(src);
InputStream in = awaitFuture(srcFS.openFile(src)
.withFileStatus(srcStatus)
.opt(FS_OPTION_OPENFILE_READ_POLICY,
FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE)
.build());
IOUtils.copyBytes(in, Files.newOutputStream(dst.toPath()), conf);
}
if (deleteSource) {

8
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/FutureDataInputStreamBuilder.java
View File

@ -17,6 +17,7 @@
*/
package org.apache.hadoop.fs;
import javax.annotation.Nullable;
import java.io.IOException;
import java.util.concurrent.CompletableFuture;
@ -34,7 +35,7 @@ import org.apache.hadoop.classification.InterfaceStability;
* options accordingly, for example:
*
* If the option is not related to the file system, the option will be ignored.
* If the option is must, but not supported by the file system, a
* If the option is must, but not supported/known by the file system, an
* {@link IllegalArgumentException} will be thrown.
*
*/
@ -51,10 +52,11 @@ public interface FutureDataInputStreamBuilder
/**
* A FileStatus may be provided to the open request.
* It is up to the implementation whether to use this or not.
* @param status status.
* @param status status: may be null
* @return the builder.
*/
default FutureDataInputStreamBuilder withFileStatus(FileStatus status) {
default FutureDataInputStreamBuilder withFileStatus(
@Nullable FileStatus status) {
return this;
}

119
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/Options.java
View File

@ -17,9 +17,13 @@
*/
package org.apache.hadoop.fs;
import java.util.Collections;
import java.util.Optional;
import java.util.Set;
import java.util.function.Function;
import java.util.function.BiFunction;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
@ -518,4 +522,119 @@ public final class Options {
MD5MD5CRC, // MD5 of block checksums, which are MD5 over chunk CRCs
COMPOSITE_CRC // Block/chunk-independent composite CRC
}
/**
* The standard {@code openFile()} options.
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public static final class OpenFileOptions {
private OpenFileOptions() {
}
/**
* Prefix for all standard filesystem options: {@value}.
*/
private static final String FILESYSTEM_OPTION = "fs.option.";
/**
* Prefix for all openFile options: {@value}.
*/
public static final String FS_OPTION_OPENFILE =
FILESYSTEM_OPTION + "openfile.";
/**
* OpenFile option for file length: {@value}.
*/
public static final String FS_OPTION_OPENFILE_LENGTH =
FS_OPTION_OPENFILE + "length";
/**
* OpenFile option for split start: {@value}.
*/
public static final String FS_OPTION_OPENFILE_SPLIT_START =
FS_OPTION_OPENFILE + "split.start";
/**
* OpenFile option for split end: {@value}.
*/
public static final String FS_OPTION_OPENFILE_SPLIT_END =
FS_OPTION_OPENFILE + "split.end";
/**
* OpenFile option for buffer size: {@value}.
*/
public static final String FS_OPTION_OPENFILE_BUFFER_SIZE =
FS_OPTION_OPENFILE + "buffer.size";
/**
* OpenFile option for read policies: {@value}.
*/
public static final String FS_OPTION_OPENFILE_READ_POLICY =
FS_OPTION_OPENFILE + "read.policy";
/**
* Set of standard options which openFile implementations
* MUST recognize, even if they ignore the actual values.
*/
public static final Set<String> FS_OPTION_OPENFILE_STANDARD_OPTIONS =
Collections.unmodifiableSet(Stream.of(
FS_OPTION_OPENFILE_BUFFER_SIZE,
FS_OPTION_OPENFILE_READ_POLICY,
FS_OPTION_OPENFILE_LENGTH,
FS_OPTION_OPENFILE_SPLIT_START,
FS_OPTION_OPENFILE_SPLIT_END)
.collect(Collectors.toSet()));
/**
* Read policy for adaptive IO: {@value}.
*/
public static final String FS_OPTION_OPENFILE_READ_POLICY_ADAPTIVE =
"adaptive";
/**
* Read policy {@value} -whateve the implementation does by default.
*/
public static final String FS_OPTION_OPENFILE_READ_POLICY_DEFAULT =
"default";
/**
* Read policy for random IO: {@value}.
*/
public static final String FS_OPTION_OPENFILE_READ_POLICY_RANDOM =
"random";
/**
* Read policy for sequential IO: {@value}.
*/
public static final String FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL =
"sequential";
/**
* Vectored IO API to be used: {@value}.
*/
public static final String FS_OPTION_OPENFILE_READ_POLICY_VECTOR =
"vector";
/**
* Whole file to be read, end-to-end: {@value}.
*/
public static final String FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE =
"whole-file";
/**
* All the current read policies as a set.
*/
public static final Set<String> FS_OPTION_OPENFILE_READ_POLICIES =
Collections.unmodifiableSet(Stream.of(
FS_OPTION_OPENFILE_READ_POLICY_ADAPTIVE,
FS_OPTION_OPENFILE_READ_POLICY_DEFAULT,
FS_OPTION_OPENFILE_READ_POLICY_RANDOM,
FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL,
FS_OPTION_OPENFILE_READ_POLICY_VECTOR,
FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE)
.collect(Collectors.toSet()));
}
}

38
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/AbstractFSBuilderImpl.java
View File

@ -46,7 +46,7 @@ import static org.apache.hadoop.thirdparty.com.google.common.base.Preconditions.
* <code>
* .opt("foofs:option.a", true)
* .opt("foofs:option.b", "value")
* .opt("barfs:cache", true)
* .opt("fs.s3a.open.option.etag", "9fe4c37c25b")
* .must("foofs:cache", true)
* .must("barfs:cache-size", 256 * 1024 * 1024)
* .build();
@ -88,6 +88,9 @@ public abstract class
/** Keep track of the keys for mandatory options. */
private final Set<String> mandatoryKeys = new HashSet<>();
/** Keep track of the optional keys. */
private final Set<String> optionalKeys = new HashSet<>();
/**
* Constructor with both optional path and path handle.
* Either or both argument may be empty, but it is an error for
@ -163,6 +166,7 @@ public abstract class
@Override
public B opt(@Nonnull final String key, @Nonnull final String value) {
mandatoryKeys.remove(key);
optionalKeys.add(key);
options.set(key, value);
return getThisBuilder();
}
@ -175,6 +179,7 @@ public abstract class
@Override
public B opt(@Nonnull final String key, boolean value) {
mandatoryKeys.remove(key);
optionalKeys.add(key);
options.setBoolean(key, value);
return getThisBuilder();
}
@ -187,10 +192,19 @@ public abstract class
@Override
public B opt(@Nonnull final String key, int value) {
mandatoryKeys.remove(key);
optionalKeys.add(key);
options.setInt(key, value);
return getThisBuilder();
}
@Override
public B opt(@Nonnull final String key, final long value) {
mandatoryKeys.remove(key);
optionalKeys.add(key);
options.setLong(key, value);
return getThisBuilder();
}
/**
* Set optional float parameter for the Builder.
*
@ -199,6 +213,7 @@ public abstract class
@Override
public B opt(@Nonnull final String key, float value) {
mandatoryKeys.remove(key);
optionalKeys.add(key);
options.setFloat(key, value);
return getThisBuilder();
}
@ -211,6 +226,7 @@ public abstract class
@Override
public B opt(@Nonnull final String key, double value) {
mandatoryKeys.remove(key);
optionalKeys.add(key);
options.setDouble(key, value);
return getThisBuilder();
}
@ -223,6 +239,7 @@ public abstract class
@Override
public B opt(@Nonnull final String key, @Nonnull final String... values) {
mandatoryKeys.remove(key);
optionalKeys.add(key);
options.setStrings(key, values);
return getThisBuilder();
}
@ -248,6 +265,7 @@ public abstract class
@Override
public B must(@Nonnull final String key, boolean value) {
mandatoryKeys.add(key);
optionalKeys.remove(key);
options.setBoolean(key, value);
return getThisBuilder();
}
@ -260,10 +278,19 @@ public abstract class
@Override
public B must(@Nonnull final String key, int value) {
mandatoryKeys.add(key);
optionalKeys.remove(key);
options.setInt(key, value);
return getThisBuilder();
}
@Override
public B must(@Nonnull final String key, final long value) {
mandatoryKeys.add(key);
optionalKeys.remove(key);
options.setLong(key, value);
return getThisBuilder();
}
/**
* Set mandatory float option.
*
@ -272,6 +299,7 @@ public abstract class
@Override
public B must(@Nonnull final String key, float value) {
mandatoryKeys.add(key);
optionalKeys.remove(key);
options.setFloat(key, value);
return getThisBuilder();
}
@ -284,6 +312,7 @@ public abstract class
@Override
public B must(@Nonnull final String key, double value) {
mandatoryKeys.add(key);
optionalKeys.remove(key);
options.setDouble(key, value);
return getThisBuilder();
}
@ -296,6 +325,7 @@ public abstract class
@Override
public B must(@Nonnull final String key, @Nonnull final String... values) {
mandatoryKeys.add(key);
optionalKeys.remove(key);
options.setStrings(key, values);
return getThisBuilder();
}
@ -314,6 +344,12 @@ public abstract class
public Set<String> getMandatoryKeys() {
return Collections.unmodifiableSet(mandatoryKeys);
}
/**
* Get all the keys that are set as optional keys.
*/
public Set<String> getOptionalKeys() {
return Collections.unmodifiableSet(optionalKeys);
}
/**
* Reject a configuration if one or more mandatory keys are

9
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/FileSystemMultipartUploader.java
View File

@ -51,6 +51,7 @@ import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.PathHandle;
import org.apache.hadoop.fs.UploadHandle;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.util.functional.FutureIO;
import static org.apache.hadoop.fs.Path.mergePaths;
import static org.apache.hadoop.io.IOUtils.cleanupWithLogger;
@ -98,7 +99,7 @@ public class FileSystemMultipartUploader extends AbstractMultipartUploader {
public CompletableFuture<UploadHandle> startUpload(Path filePath)
throws IOException {
checkPath(filePath);
return FutureIOSupport.eval(() -> {
return FutureIO.eval(() -> {
Path collectorPath = createCollectorPath(filePath);
fs.mkdirs(collectorPath, FsPermission.getDirDefault());
@ -116,7 +117,7 @@ public class FileSystemMultipartUploader extends AbstractMultipartUploader {
throws IOException {
checkPutArguments(filePath, inputStream, partNumber, uploadId,
lengthInBytes);
return FutureIOSupport.eval(() -> innerPutPart(filePath,
return FutureIO.eval(() -> innerPutPart(filePath,
inputStream, partNumber, uploadId, lengthInBytes));
}
@ -179,7 +180,7 @@ public class FileSystemMultipartUploader extends AbstractMultipartUploader {
Map<Integer, PartHandle> handleMap) throws IOException {
checkPath(filePath);
return FutureIOSupport.eval(() ->
return FutureIO.eval(() ->
innerComplete(uploadId, filePath, handleMap));
}
@ -251,7 +252,7 @@ public class FileSystemMultipartUploader extends AbstractMultipartUploader {
Path collectorPath = new Path(new String(uploadIdByteArray, 0,
uploadIdByteArray.length, Charsets.UTF_8));
return FutureIOSupport.eval(() -> {
return FutureIO.eval(() -> {
// force a check for a file existing; raises FNFE if not found
fs.getFileStatus(collectorPath);
fs.delete(collectorPath, true);

8
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/FutureDataInputStreamBuilderImpl.java
View File

@ -19,6 +19,7 @@
package org.apache.hadoop.fs.impl;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.io.IOException;
import java.util.concurrent.CompletableFuture;
@ -47,7 +48,7 @@ import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.IO_FILE_BUFFER_
* options accordingly, for example:
*
* If the option is not related to the file system, the option will be ignored.
* If the option is must, but not supported by the file system, a
* If the option is must, but not supported/known by the file system, an
* {@link IllegalArgumentException} will be thrown.
*
*/
@ -147,8 +148,9 @@ public abstract class FutureDataInputStreamBuilderImpl
}
@Override
public FutureDataInputStreamBuilder withFileStatus(FileStatus st) {
this.status = requireNonNull(st, "status");
public FutureDataInputStreamBuilder withFileStatus(
@Nullable FileStatus st) {
this.status = st;
return this;
}

83
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/FutureIOSupport.java
View File

@ -20,7 +20,6 @@ package org.apache.hadoop.fs.impl;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionException;
import java.util.concurrent.ExecutionException;
@ -37,14 +36,16 @@ import org.apache.hadoop.util.functional.FutureIO;
/**
* Support for future IO and the FS Builder subclasses.
* If methods in here are needed for applications, promote
* to {@link FutureIO} for public use -with the original
* method relaying to it. This is to ensure that external
* filesystem implementations can safely use these methods
* All methods in this class have been superceded by those in
* {@link FutureIO}.
* The methods here are retained but all marked as deprecated.
* This is to ensure that any external
* filesystem implementations can still use these methods
* without linkage problems surfacing.
*/
@InterfaceAudience.Private
@InterfaceStability.Unstable
@Deprecated
public final class FutureIOSupport {
private FutureIOSupport() {
@ -53,6 +54,7 @@ public final class FutureIOSupport {
/**
* Given a future, evaluate it. Raised exceptions are
* extracted and handled.
* See {@link FutureIO#awaitFuture(Future, long, TimeUnit)}.
* @param future future to evaluate
* @param <T> type of the result.
* @return the result, if all went well.
@ -60,7 +62,8 @@ public final class FutureIOSupport {
* @throws IOException if something went wrong
* @throws RuntimeException any nested RTE thrown
*/
public static <T> T awaitFuture(final Future<T> future)
@Deprecated
public static <T> T awaitFuture(final Future<T> future)
throws InterruptedIOException, IOException, RuntimeException {
return FutureIO.awaitFuture(future);
}
@ -69,6 +72,7 @@ public final class FutureIOSupport {
/**
* Given a future, evaluate it. Raised exceptions are
* extracted and handled.
* See {@link FutureIO#awaitFuture(Future, long, TimeUnit)}.
* @param future future to evaluate
* @param <T> type of the result.
* @return the result, if all went well.
@ -77,6 +81,7 @@ public final class FutureIOSupport {
* @throws RuntimeException any nested RTE thrown
* @throws TimeoutException the future timed out.
*/
@Deprecated
public static <T> T awaitFuture(final Future<T> future,
final long timeout,
final TimeUnit unit)
@ -88,10 +93,7 @@ public final class FutureIOSupport {
/**
* From the inner cause of an execution exception, extract the inner cause
* if it is an IOE or RTE.
* This will always raise an exception, either the inner IOException,
* an inner RuntimeException, or a new IOException wrapping the raised
* exception.
*
* See {@link FutureIO#raiseInnerCause(ExecutionException)}.
* @param e exception.
* @param <T> type of return value.
* @return nothing, ever.
@ -99,6 +101,7 @@ public final class FutureIOSupport {
* any non-Runtime-Exception
* @throws RuntimeException if that is the inner cause.
*/
@Deprecated
public static <T> T raiseInnerCause(final ExecutionException e)
throws IOException {
return FutureIO.raiseInnerCause(e);
@ -107,6 +110,7 @@ public final class FutureIOSupport {
/**
* Extract the cause of a completion failure and rethrow it if an IOE
* or RTE.
* See {@link FutureIO#raiseInnerCause(CompletionException)}.
* @param e exception.
* @param <T> type of return value.
* @return nothing, ever.
@ -114,20 +118,15 @@ public final class FutureIOSupport {
* any non-Runtime-Exception
* @throws RuntimeException if that is the inner cause.
*/
@Deprecated
public static <T> T raiseInnerCause(final CompletionException e)
throws IOException {
return FutureIO.raiseInnerCause(e);
}
/**
* Propagate options to any builder, converting everything with the
* prefix to an option where, if there were 2+ dot-separated elements,
* it is converted to a schema.
* <pre>
* fs.example.s3a.option => s3a:option
* fs.example.fs.io.policy => s3a.io.policy
* fs.example.something => something
* </pre>
* Propagate options to any builder.
* {@link FutureIO#propagateOptions(FSBuilder, Configuration, String, String)}
* @param builder builder to modify
* @param conf configuration to read
* @param optionalPrefix prefix for optional settings
@ -136,56 +135,39 @@ public final class FutureIOSupport {
* @param <U> type of builder
* @return the builder passed in.
*/
@Deprecated
public static <T, U extends FSBuilder<T, U>>
FSBuilder<T, U> propagateOptions(
final FSBuilder<T, U> builder,
final Configuration conf,
final String optionalPrefix,
final String mandatoryPrefix) {
propagateOptions(builder, conf,
optionalPrefix, false);
propagateOptions(builder, conf,
mandatoryPrefix, true);
return builder;
return FutureIO.propagateOptions(builder,
conf, optionalPrefix, mandatoryPrefix);
}
/**
* Propagate options to any builder, converting everything with the
* prefix to an option where, if there were 2+ dot-separated elements,
* it is converted to a schema.
* <pre>
* fs.example.s3a.option => s3a:option
* fs.example.fs.io.policy => s3a.io.policy
* fs.example.something => something
* </pre>
* Propagate options to any builder.
* {@link FutureIO#propagateOptions(FSBuilder, Configuration, String, boolean)}
* @param builder builder to modify
* @param conf configuration to read
* @param prefix prefix to scan/strip
* @param mandatory are the options to be mandatory or optional?
*/
@Deprecated
public static void propagateOptions(
final FSBuilder<?, ?> builder,
final Configuration conf,
final String prefix,
final boolean mandatory) {
final String p = prefix.endsWith(".") ? prefix : (prefix + ".");
final Map<String, String> propsWithPrefix = conf.getPropsWithPrefix(p);
for (Map.Entry<String, String> entry : propsWithPrefix.entrySet()) {
// change the schema off each entry
String key = entry.getKey();
String val = entry.getValue();
if (mandatory) {
builder.must(key, val);
} else {
builder.opt(key, val);
}
}
FutureIO.propagateOptions(builder, conf, prefix, mandatory);
}
/**
* Evaluate a CallableRaisingIOE in the current thread,
* converting IOEs to RTEs and propagating.
* See {@link FutureIO#eval(CallableRaisingIOE)}.
*
* @param callable callable to invoke
* @param <T> Return type.
* @return the evaluated result.
@ -194,17 +176,6 @@ public final class FutureIOSupport {
*/
public static <T> CompletableFuture<T> eval(
CallableRaisingIOE<T> callable) {
CompletableFuture<T> result = new CompletableFuture<>();
try {
result.complete(callable.apply());
} catch (UnsupportedOperationException | IllegalArgumentException tx) {
// fail fast here
throw tx;
} catch (Throwable tx) {
// fail lazily here to ensure callers expect all File IO operations to
// surface later
result.completeExceptionally(tx);
}
return result;
return FutureIO.eval(callable);
}
}

13
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/OpenFileParameters.java
View File

@ -38,6 +38,9 @@ public class OpenFileParameters {
*/
private Set<String> mandatoryKeys;
/** The optional keys. */
private Set<String> optionalKeys;
/**
* Options set during the build sequence.
*/
@ -61,6 +64,11 @@ public class OpenFileParameters {
return this;
}
public OpenFileParameters withOptionalKeys(final Set<String> keys) {
this.optionalKeys = requireNonNull(keys);
return this;
}
public OpenFileParameters withOptions(final Configuration opts) {
this.options = requireNonNull(opts);
return this;
@ -80,6 +88,10 @@ public class OpenFileParameters {
return mandatoryKeys;
}
public Set<String> getOptionalKeys() {
return optionalKeys;
}
public Configuration getOptions() {
return options;
}
@ -91,4 +103,5 @@ public class OpenFileParameters {
public FileStatus getStatus() {
return status;
}
}

11
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/impl/WrappedIOException.java
View File

@ -20,7 +20,6 @@ package org.apache.hadoop.fs.impl;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.util.concurrent.ExecutionException;
import org.apache.hadoop.thirdparty.com.google.common.base.Preconditions;
@ -28,13 +27,11 @@ import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
/**
* A wrapper for an IOException which
* {@link FutureIOSupport#raiseInnerCause(ExecutionException)} knows to
* always extract the exception.
* A wrapper for an IOException.
*
* The constructor signature guarantees the cause will be an IOException,
* and as it checks for a null-argument, non-null.
* @deprecated use the {@code UncheckedIOException}.
* @deprecated use the {@code UncheckedIOException} directly.]
*/
@Deprecated
@InterfaceAudience.Private
@ -52,8 +49,4 @@ public class WrappedIOException extends UncheckedIOException {
super(Preconditions.checkNotNull(cause));
}
@Override
public synchronized IOException getCause() {
return (IOException) super.getCause();
}
}

9
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/CommandWithDestination.java
View File

@ -55,6 +55,9 @@ import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.IO_FILE_BUFFER_
import static org.apache.hadoop.fs.CreateFlag.CREATE;
import static org.apache.hadoop.fs.CreateFlag.LAZY_PERSIST;
import static org.apache.hadoop.fs.CreateFlag.OVERWRITE;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE;
import static org.apache.hadoop.util.functional.FutureIO.awaitFuture;
/**
* Provides: argument processing to ensure the destination is valid
@ -348,7 +351,11 @@ abstract class CommandWithDestination extends FsCommand {
src.fs.setVerifyChecksum(verifyChecksum);
InputStream in = null;
try {
in = src.fs.open(src.path);
in = awaitFuture(src.fs.openFile(src.path)
.withFileStatus(src.stat)
.opt(FS_OPTION_OPENFILE_READ_POLICY,
FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE)
.build());
copyStreamToTarget(in, target);
preserveAttributes(src, target, preserveRawXattrs);
} finally {

3
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/CopyCommands.java
View File

@ -98,7 +98,8 @@ class CopyCommands {
try {
for (PathData src : srcs) {
if (src.stat.getLen() != 0) {
try (FSDataInputStream in = src.fs.open(src.path)) {
// Always do sequential reads.
try (FSDataInputStream in = src.openForSequentialIO()) {
IOUtils.copyBytes(in, out, getConf(), false);
writeDelimiter(out);
}

3
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/Display.java
View File

@ -105,7 +105,8 @@ class Display extends FsCommand {
}
protected InputStream getInputStream(PathData item) throws IOException {
return item.fs.open(item.path);
// Always do sequential reads;
return item.openForSequentialIO();
}
}

8
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/Head.java
View File

@ -28,6 +28,8 @@ import java.io.IOException;
import java.util.LinkedList;
import java.util.List;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL;
/**
* Show the first 1KB of the file.
*/
@ -68,11 +70,9 @@ class Head extends FsCommand {
}
private void dumpToOffset(PathData item) throws IOException {
FSDataInputStream in = item.fs.open(item.path);
try {
try (FSDataInputStream in = item.openFile(
FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL)) {
IOUtils.copyBytes(in, System.out, endingOffset, false);
} finally {
in.close();
}
}
}

35
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/PathData.java
View File

@ -29,6 +29,7 @@ import java.util.regex.Pattern;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.LocalFileSystem;
@ -39,6 +40,10 @@ import org.apache.hadoop.fs.PathIsNotDirectoryException;
import org.apache.hadoop.fs.PathNotFoundException;
import org.apache.hadoop.fs.RemoteIterator;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_LENGTH;
import static org.apache.hadoop.util.functional.FutureIO.awaitFuture;
import static org.apache.hadoop.util.functional.RemoteIterators.mappingRemoteIterator;
/**
@ -601,4 +606,34 @@ public class PathData implements Comparable<PathData> {
public int hashCode() {
return path.hashCode();
}
/**
* Open a file for sequential IO.
* <p></p>
* This uses FileSystem.openFile() to request sequential IO;
* the file status is also passed in.
* Filesystems may use to optimize their IO.
* @return an input stream
* @throws IOException failure
*/
protected FSDataInputStream openForSequentialIO()
throws IOException {
return openFile(FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL);
}
/**
* Open a file.
* @param policy fadvise policy.
* @return an input stream
* @throws IOException failure
*/
protected FSDataInputStream openFile(final String policy) throws IOException {
return awaitFuture(fs.openFile(path)
.opt(FS_OPTION_OPENFILE_READ_POLICY,
policy)
.opt(FS_OPTION_OPENFILE_LENGTH,
stat.getLen()) // file length hint for object stores
.build());
}
}

11
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/shell/Tail.java
View File

@ -30,6 +30,8 @@ import org.apache.hadoop.io.IOUtils;
import org.apache.hadoop.thirdparty.com.google.common.annotations.VisibleForTesting;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL;
/**
* Get a listing of all files in that match the file patterns.
*/
@ -107,16 +109,15 @@ class Tail extends FsCommand {
if (offset < 0) {
offset = Math.max(fileSize + offset, 0);
}
FSDataInputStream in = item.fs.open(item.path);
try {
// Always do sequential reads.
try (FSDataInputStream in = item.openFile(
FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL)) {
in.seek(offset);
// use conf so the system configured io block size is used
IOUtils.copyBytes(in, System.out, getConf(), false);
offset = in.getPos();
} finally {
in.close();
}
return offset;
}
}

9
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/StoreStatisticNames.java
View File

@ -118,6 +118,9 @@ public final class StoreStatisticNames {
/** {@value}. */
public static final String OP_OPEN = "op_open";
/** Call to openFile() {@value}. */
public static final String OP_OPENFILE = "op_openfile";
/** {@value}. */
public static final String OP_REMOVE_ACL = "op_remove_acl";
@ -323,6 +326,12 @@ public final class StoreStatisticNames {
public static final String ACTION_EXECUTOR_ACQUIRED =
"action_executor_acquired";
/**
* A file was opened: {@value}.
*/
public static final String ACTION_FILE_OPENED
= "action_file_opened";
/**
* An HTTP HEAD request was made: {@value}.
*/

19
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/StreamStatisticNames.java
View File

@ -76,7 +76,7 @@ public final class StreamStatisticNames {
public static final String STREAM_READ_CLOSED = "stream_read_closed";
/**
* Total count of times an attempt to close an input stream was made
* Total count of times an attempt to close an input stream was made.
* Value: {@value}.
*/
public static final String STREAM_READ_CLOSE_OPERATIONS
@ -118,6 +118,23 @@ public final class StreamStatisticNames {
public static final String STREAM_READ_OPERATIONS_INCOMPLETE
= "stream_read_operations_incomplete";
/**
* count/duration of aborting a remote stream during stream IO
* IO.
* Value: {@value}.
*/
public static final String STREAM_READ_REMOTE_STREAM_ABORTED
= "stream_read_remote_stream_aborted";
/**
* count/duration of closing a remote stream,
* possibly including draining the stream to recycle
* the HTTP connection.
* Value: {@value}.
*/
public static final String STREAM_READ_REMOTE_STREAM_DRAINED
= "stream_read_remote_stream_drain";
/**
* Count of version mismatches encountered while reading an input stream.
* Value: {@value}.

44
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/statistics/impl/IOStatisticsBinding.java
View File

@ -521,23 +521,39 @@ public final class IOStatisticsBinding {
// create the tracker outside try-with-resources so
// that failures can be set in the catcher.
DurationTracker tracker = createTracker(factory, statistic);
try {
// exec the input function and return its value
return input.apply();
} catch (IOException | RuntimeException e) {
// input function failed: note it
tracker.failed();
// and rethrow
throw e;
} finally {
// update the tracker.
// this is called after the catch() call would have
// set the failed flag.
tracker.close();
}
return invokeTrackingDuration(tracker, input);
};
}
/**
* Given an IOException raising callable/lambda expression,
* execute it, updating the tracker on success/failure.
* @param tracker duration tracker.
* @param input input callable.
* @param <B> return type.
* @return the result of the invocation
* @throws IOException on failure.
*/
public static <B> B invokeTrackingDuration(
final DurationTracker tracker,
final CallableRaisingIOE<B> input)
throws IOException {
try {
// exec the input function and return its value
return input.apply();
} catch (IOException | RuntimeException e) {
// input function failed: note it
tracker.failed();
// and rethrow
throw e;
} finally {
// update the tracker.
// this is called after the catch() call would have
// set the failed flag.
tracker.close();
}
}
/**
* Given an IOException raising Consumer,
* return a new one which wraps the inner and tracks

14
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/SequenceFile.java
View File

@ -60,6 +60,11 @@ import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.IO_SEQFILE_COMP
import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.IO_SEQFILE_COMPRESS_BLOCKSIZE_KEY;
import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.IO_SKIP_CHECKSUM_ERRORS_DEFAULT;
import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.IO_SKIP_CHECKSUM_ERRORS_KEY;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_BUFFER_SIZE;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_LENGTH;
import static org.apache.hadoop.util.functional.FutureIO.awaitFuture;
/**
* <code>SequenceFile</code>s are flat files consisting of binary key/value
@ -1959,7 +1964,14 @@ public class SequenceFile {
*/
protected FSDataInputStream openFile(FileSystem fs, Path file,
int bufferSize, long length) throws IOException {
return fs.open(file, bufferSize);
FutureDataInputStreamBuilder builder = fs.openFile(file)
.opt(FS_OPTION_OPENFILE_READ_POLICY,
FS_OPTION_OPENFILE_READ_POLICY_SEQUENTIAL)
.opt(FS_OPTION_OPENFILE_BUFFER_SIZE, bufferSize);
if (length >= 0) {
builder.opt(FS_OPTION_OPENFILE_LENGTH, length);
}
return awaitFuture(builder.build());
}
/**

6
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/JsonSerialization.java
View File

@ -50,6 +50,8 @@ import org.apache.hadoop.fs.FutureDataInputStreamBuilder;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.PathIOException;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE;
import static org.apache.hadoop.util.functional.FutureIO.awaitFuture;
/**
@ -266,7 +268,9 @@ public class JsonSerialization<T> {
if (status != null && status.getLen() == 0) {
throw new EOFException("No data in " + path);
}
FutureDataInputStreamBuilder builder = fs.openFile(path);
FutureDataInputStreamBuilder builder = fs.openFile(path)
.opt(FS_OPTION_OPENFILE_READ_POLICY,
FS_OPTION_OPENFILE_READ_POLICY_WHOLE_FILE);
if (status != null) {
builder.withFileStatus(status);
}

2
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/functional/CommonCallableSupplier.java
View File

@ -34,7 +34,7 @@ import org.slf4j.LoggerFactory;
import org.apache.hadoop.util.DurationInfo;
import static org.apache.hadoop.fs.impl.FutureIOSupport.raiseInnerCause;
import static org.apache.hadoop.util.functional.FutureIO.raiseInnerCause;
/**
* A bridge from Callable to Supplier; catching exceptions

90
hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/functional/FutureIO.java
View File

@ -21,6 +21,8 @@ package org.apache.hadoop.util.functional;
import java.io.IOException;
import java.io.InterruptedIOException;
import java.io.UncheckedIOException;
import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.CompletionException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
@ -29,6 +31,8 @@ import java.util.concurrent.TimeoutException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSBuilder;
/**
* Future IO Helper methods.
@ -86,6 +90,8 @@ public final class FutureIO {
* extracted and rethrown.
* </p>
* @param future future to evaluate
* @param timeout timeout to wait
* @param unit time unit.
* @param <T> type of the result.
* @return the result, if all went well.
* @throws InterruptedIOException future was interrupted
@ -185,4 +191,88 @@ public final class FutureIO {
}
}
/**
* Propagate options to any builder, converting everything with the
* prefix to an option where, if there were 2+ dot-separated elements,
* it is converted to a schema.
* See {@link #propagateOptions(FSBuilder, Configuration, String, boolean)}.
* @param builder builder to modify
* @param conf configuration to read
* @param optionalPrefix prefix for optional settings
* @param mandatoryPrefix prefix for mandatory settings
* @param <T> type of result
* @param <U> type of builder
* @return the builder passed in.
*/
public static <T, U extends FSBuilder<T, U>>
FSBuilder<T, U> propagateOptions(
final FSBuilder<T, U> builder,
final Configuration conf,
final String optionalPrefix,
final String mandatoryPrefix) {
propagateOptions(builder, conf,
optionalPrefix, false);
propagateOptions(builder, conf,
mandatoryPrefix, true);
return builder;
}
/**
* Propagate options to any builder, converting everything with the
* prefix to an option where, if there were 2+ dot-separated elements,
* it is converted to a schema.
* <pre>
* fs.example.s3a.option becomes "s3a.option"
* fs.example.fs.io.policy becomes "fs.io.policy"
* fs.example.something becomes "something"
* </pre>
* @param builder builder to modify
* @param conf configuration to read
* @param prefix prefix to scan/strip
* @param mandatory are the options to be mandatory or optional?
*/
public static void propagateOptions(
final FSBuilder<?, ?> builder,
final Configuration conf,
final String prefix,
final boolean mandatory) {
final String p = prefix.endsWith(".") ? prefix : (prefix + ".");
final Map<String, String> propsWithPrefix = conf.getPropsWithPrefix(p);
for (Map.Entry<String, String> entry : propsWithPrefix.entrySet()) {
// change the schema off each entry
String key = entry.getKey();
String val = entry.getValue();
if (mandatory) {
builder.must(key, val);
} else {
builder.opt(key, val);
}
}
}
/**
* Evaluate a CallableRaisingIOE in the current thread,
* converting IOEs to RTEs and propagating.
* @param callable callable to invoke
* @param <T> Return type.
* @return the evaluated result.
* @throws UnsupportedOperationException fail fast if unsupported
* @throws IllegalArgumentException invalid argument
*/
public static <T> CompletableFuture<T> eval(
CallableRaisingIOE<T> callable) {
CompletableFuture<T> result = new CompletableFuture<>();
try {
result.complete(callable.apply());
} catch (UnsupportedOperationException | IllegalArgumentException tx) {
// fail fast here
throw tx;
} catch (Throwable tx) {
// fail lazily here to ensure callers expect all File IO operations to
// surface later
result.completeExceptionally(tx);
}
return result;
}
}

90
hadoop-common-project/hadoop-common/src/site/markdown/filesystem/filesystem.md
View File

@ -814,97 +814,11 @@ exists in the metadata, but no copies of any its blocks can be located;
### `FSDataInputStreamBuilder openFile(Path path)`
Creates a [`FSDataInputStreamBuilder`](fsdatainputstreambuilder.html)
to construct a operation to open the file at `path` for reading.
See [openFile()](openfile.html).
When `build()` is invoked on the returned `FSDataInputStreamBuilder` instance,
the builder parameters are verified and
`openFileWithOptions(Path, OpenFileParameters)` invoked.
This (protected) operation returns a `CompletableFuture<FSDataInputStream>`
which, when its `get()` method is called, either returns an input
stream of the contents of opened file, or raises an exception.
The base implementation of the `openFileWithOptions(PathHandle, OpenFileParameters)`
ultimately invokes `open(Path, int)`.
Thus the chain `openFile(path).build().get()` has the same preconditions
and postconditions as `open(Path p, int bufferSize)`
However, there is one difference which implementations are free to
take advantage of:
The returned stream MAY implement a lazy open where file non-existence or
access permission failures may not surface until the first `read()` of the
actual data.
The `openFile()` operation may check the state of the filesystem during its
invocation, but as the state of the filesystem may change betwen this call and
the actual `build()` and `get()` operations, this file-specific
preconditions (file exists, file is readable, etc) MUST NOT be checked here.
FileSystem implementations which do not implement `open(Path, int)`
MAY postpone raising an `UnsupportedOperationException` until either the
`FSDataInputStreamBuilder.build()` or the subsequent `get()` call,
else they MAY fail fast in the `openFile()` call.
### Implementors notes
The base implementation of `openFileWithOptions()` actually executes
the `open(path)` operation synchronously, yet still returns the result
or any failures in the `CompletableFuture<>`, so as to ensure that users
code expecting this.
Any filesystem where the time to open a file may be significant SHOULD
execute it asynchronously by submitting the operation in some executor/thread
pool. This is particularly recommended for object stores and other filesystems
likely to be accessed over long-haul connections.
Arbitrary filesystem-specific options MAY be supported; these MUST
be prefixed with either the filesystem schema, e.g. `hdfs.`
or in the "fs.SCHEMA" format as normal configuration settings `fs.hdfs`). The
latter style allows the same configuration option to be used for both
filesystem configuration and file-specific configuration.
It SHOULD be possible to always open a file without specifying any options,
so as to present a consistent model to users. However, an implementation MAY
opt to require one or more mandatory options to be set.
The returned stream may perform "lazy" evaluation of file access. This is
relevant for object stores where the probes for existence are expensive, and,
even with an asynchronous open, may be considered needless.
### `FSDataInputStreamBuilder openFile(PathHandle)`
Creates a `FSDataInputStreamBuilder` to build an operation to open a file.
Creates a [`FSDataInputStreamBuilder`](fsdatainputstreambuilder.html)
to construct a operation to open the file identified by the given `PathHandle` for reading.
When `build()` is invoked on the returned `FSDataInputStreamBuilder` instance,
the builder parameters are verified and
`openFileWithOptions(PathHandle, OpenFileParameters)` invoked.
This (protected) operation returns a `CompletableFuture<FSDataInputStream>`
which, when its `get()` method is called, either returns an input
stream of the contents of opened file, or raises an exception.
The base implementation of the `openFileWithOptions(PathHandle, OpenFileParameters)` method
returns a future which invokes `open(Path, int)`.
Thus the chain `openFile(pathhandle).build().get()` has the same preconditions
and postconditions as `open(Pathhandle, int)`
As with `FSDataInputStreamBuilder openFile(PathHandle)`, the `openFile()`
call must not be where path-specific preconditions are checked -that
is postponed to the `build()` and `get()` calls.
FileSystem implementations which do not implement `open(PathHandle handle, int bufferSize)`
MAY postpone raising an `UnsupportedOperationException` until either the
`FSDataInputStreamBuilder.build()` or the subsequent `get()` call,
else they MAY fail fast in the `openFile()` call.
The base implementation raises this exception in the `build()` operation;
other implementations SHOULD copy this.
See [openFile()](openfile.html).
### `PathHandle getPathHandle(FileStatus stat, HandleOpt... options)`

588
hadoop-common-project/hadoop-common/src/site/markdown/filesystem/fsdatainputstreambuilder.md
View File

@ -13,10 +13,10 @@
-->
<!-- ============================================================= -->
<!-- CLASS: FSDataInputStreamBuilder -->
<!-- CLASS: FutureDataInputStreamBuilder -->
<!-- ============================================================= -->
# class `org.apache.hadoop.fs.FSDataInputStreamBuilder`
# class `org.apache.hadoop.fs.FutureDataInputStreamBuilder`
<!-- MACRO{toc|fromDepth=1|toDepth=2} -->
@ -27,7 +27,7 @@ file for reading.
## Invariants
The `FSDataInputStreamBuilder` interface does not require parameters or
The `FutureDataInputStreamBuilder` interface does not require parameters or
or the state of `FileSystem` until [`build()`](#build) is
invoked and/or during the asynchronous open operation itself.
@ -39,11 +39,11 @@ path validation.
## Implementation-agnostic parameters.
### <a name="Builder.bufferSize"></a> `FSDataInputStreamBuilder bufferSize(int bufSize)`
### <a name="Builder.bufferSize"></a> `FutureDataInputStreamBuilder bufferSize(int bufSize)`
Set the size of the buffer to be used.
### <a name="Builder.withFileStatus"></a> `FSDataInputStreamBuilder withFileStatus(FileStatus status)`
### <a name="Builder.withFileStatus"></a> `FutureDataInputStreamBuilder withFileStatus(FileStatus status)`
A `FileStatus` instance which refers to the file being opened.
@ -53,7 +53,7 @@ So potentially saving on remote calls especially to object stores.
Requirements:
* `status != null`
* `status.getPath()` == the resolved path of the file being opened.
* `status.getPath().getName()` == the name of the file being opened.
The path validation MUST take place if the store uses the `FileStatus` when
it opens files, and MAY be performed otherwise. The validation
@ -65,27 +65,85 @@ If a filesystem implementation extends the `FileStatus` returned in its
implementation MAY use this information when opening the file.
This is relevant with those stores which return version/etag information,
including the S3A and ABFS connectors -they MAY use this to guarantee that
the file they opened is exactly the one returned in the listing.
-they MAY use this to guarantee that the file they opened
is exactly the one returned in the listing.
The final `status.getPath().getName()` element of the supplied status MUST equal
the name value of the path supplied to the `openFile(path)` call.
Filesystems MUST NOT validate the rest of the path.
This is needed to support viewfs and other mount-point wrapper filesystems
where schemas and paths are different. These often create their own FileStatus results
Preconditions
```python
status == null or status.getPath().getName() == path.getName()
```
Filesystems MUST NOT require the class of `status` to equal
that of any specific subclass their implementation returns in filestatus/list
operations. This is to support wrapper filesystems and serialization/deserialization
of the status.
### Set optional or mandatory parameters
FSDataInputStreamBuilder opt(String key, ...)
FSDataInputStreamBuilder must(String key, ...)
FutureDataInputStreamBuilder opt(String key, ...)
FutureDataInputStreamBuilder must(String key, ...)
Set optional or mandatory parameters to the builder. Using `opt()` or `must()`,
client can specify FS-specific parameters without inspecting the concrete type
of `FileSystem`.
Example:
```java
out = fs.openFile(path)
.opt("fs.s3a.experimental.input.fadvise", "random")
.must("fs.s3a.readahead.range", 256 * 1024)
.must("fs.option.openfile.read.policy", "random")
.opt("fs.http.connection.timeout", 30_000L)
.withFileStatus(statusFromListing)
.build()
.get();
```
Here the read policy of `random` has been specified,
with the requirement that the filesystem implementation must understand the option.
An http-specific option has been supplied which may be interpreted by any store;
If the filesystem opening the file does not recognize the option, it can safely be
ignored.
### When to use `opt()` versus `must()`
The difference between `opt()` versus `must()` is how the FileSystem opening
the file must react to an option which it does not recognize.
```python
def must(name, value):
if not name in known_keys:
raise IllegalArgumentException
if not name in supported_keys:
raise UnsupportedException
def opt(name, value):
if not name in known_keys:
# ignore option
```
For any known key, the validation of the `value` argument MUST be the same
irrespective of how the (key, value) pair was declared.
1. For a filesystem-specific option, it is the choice of the implementation
how to validate the entry.
1. For standard options, the specification of what is a valid `value` is
defined in this filesystem specification, validated through contract
tests.
#### Implementation Notes
Checking for supported options must be performed in the `build()` operation.
@ -93,9 +151,9 @@ Checking for supported options must be performed in the `build()` operation.
1. If a mandatory parameter declared via `must(key, value)`) is not recognized,
`IllegalArgumentException` MUST be thrown.
1. If a mandatory parameter declared via `must(key, value)`) relies on
1. If a mandatory parameter declared via `must(key, value)` relies on
a feature which is recognized but not supported in the specific
Filesystem/FileContext instance `UnsupportedException` MUST be thrown.
`FileSystem`/`FileContext` instance `UnsupportedException` MUST be thrown.
The behavior of resolving the conflicts between the parameters set by
builder methods (i.e., `bufferSize()`) and `opt()`/`must()` is as follows:
@ -110,13 +168,18 @@ custom subclasses.
This is critical to ensure safe use of the feature: directory listing/
status serialization/deserialization can result result in the `withFileStatus()`
argumennt not being the custom subclass returned by the Filesystem instance's
argument not being the custom subclass returned by the Filesystem instance's
own `getFileStatus()`, `listFiles()`, `listLocatedStatus()` calls, etc.
In such a situation the implementations must:
1. Validate the path (always).
1. Use the status/convert to the custom type, *or* simply discard it.
1. Verify that `status.getPath().getName()` matches the current `path.getName()`
value. The rest of the path MUST NOT be validated.
1. Use any status fields as desired -for example the file length.
Even if not values of the status are used, the presence of the argument
can be interpreted as the caller declaring that they believe the file
to be present and of the given size.
## Builder interface
@ -128,26 +191,499 @@ completed, returns an input stream which can read data from the filesystem.
The `build()` operation MAY perform the validation of the file's existence,
its kind, so rejecting attempts to read from a directory or non-existent
file. **Alternatively**, the `build()` operation may delay all checks
until an asynchronous operation whose outcome is provided by the `Future`
file. Alternatively
* file existence/status checks MAY be performed asynchronously within the returned
`CompletableFuture<>`.
* file existence/status checks MAY be postponed until the first byte is read in
any of the read such as `read()` or `PositionedRead`.
That is, the precondition `exists(FS, path)` and `isFile(FS, path)` are
only guaranteed to have been met after the `get()` on the returned future is successful.
only guaranteed to have been met after the `get()` called on returned future
and an attempt has been made to read the stream.
Thus, if even a file does not exist, the following call will still succeed, returning
a future to be evaluated.
Thus, if even when file does not exist, or is a directory rather than a file,
the following call MUST succeed, returning a `CompletableFuture` to be evaluated.
```java
Path p = new Path("file://tmp/file-which-does-not-exist");
CompletableFuture<FSDataInputStream> future = p.getFileSystem(conf)
.openFile(p)
.build;
.build();
```
The preconditions for opening the file are checked during the asynchronous
evaluation, and so will surface when the future is completed:
The inability to access/read a file MUST raise an `IOException`or subclass
in either the future's `get()` call, or, for late binding operations,
when an operation to read data is invoked.
Therefore the following sequence SHALL fail when invoked on the
`future` returned by the previous example.
```java
FSDataInputStream in = future.get();
future.get().read();
```
Access permission checks have the same visibility requirements: permission failures
MUST be delayed until the `get()` call and MAY be delayed into subsequent operations.
Note: some operations on the input stream, such as `seek()` may not attempt any IO
at all. Such operations MAY NOT raise exceotions when interacting with
nonexistent/unreadable files.
## <a name="options"></a> Standard `openFile()` options since Hadoop 3.3.3
These are options which `FileSystem` and `FileContext` implementation
MUST recognise and MAY support by changing the behavior of
their input streams as appropriate.
Hadoop 3.3.0 added the `openFile()` API; these standard options were defined in
a later release. Therefore, although they are "well known", unless confident that
the application will only be executed against releases of Hadoop which knows of
the options -applications SHOULD set the options via `opt()` calls rather than `must()`.
When opening a file through the `openFile()` builder API, callers MAY use
both `.opt(key, value)` and `.must(key, value)` calls to set standard and
filesystem-specific options.
If set as an `opt()` parameter, unsupported "standard" options MUST be ignored,
as MUST unrecognized standard options.
If set as a `must()` parameter, unsupported "standard" options MUST be ignored.
unrecognized standard options MUST be rejected.
The standard `openFile()` options are defined
in `org.apache.hadoop.fs.OpenFileOptions`; they all SHALL start
with `fs.option.openfile.`.
Note that while all `FileSystem`/`FileContext` instances SHALL support these
options to the extent that `must()` declarations SHALL NOT fail, the
implementations MAY support them to the extent of interpreting the values. This
means that it is not a requirement for the stores to actually read the read
policy or file length values and use them when opening files.
Unless otherwise stated, they SHOULD be viewed as hints.
Note: if a standard option is added such that if set but not
supported would be an error, then implementations SHALL reject it. For example,
the S3A filesystem client supports the ability to push down SQL commands. If
something like that were ever standardized, then the use of the option, either
in `opt()` or `must()` argument MUST be rejected for filesystems which don't
support the feature.
### <a name="buffer.size"></a> Option: `fs.option.openfile.buffer.size`
Read buffer size in bytes.
This overrides the default value set in the configuration with the option
`io.file.buffer.size`.
It is supported by all filesystem clients which allow for stream-specific buffer
sizes to be set via `FileSystem.open(path, buffersize)`.
### <a name="read.policy"></a> Option: `fs.option.openfile.read.policy`
Declare the read policy of the input stream. This is a hint as to what the
expected read pattern of an input stream will be. This MAY control readahead,
buffering and other optimizations.
Sequential reads may be optimized with prefetching data and/or reading data in
larger blocks. Some applications (e.g. distCp) perform sequential IO even over
columnar data.
In contrast, random IO reads data in different parts of the file using a
sequence of `seek()/read()`
or via the `PositionedReadable` or `ByteBufferPositionedReadable` APIs.
Random IO performance may be best if little/no prefetching takes place, along
with other possible optimizations
Queries over columnar formats such as Apache ORC and Apache Parquet perform such
random IO; other data formats may be best read with sequential or whole-file
policies.
What is key is that optimizing reads for seqential reads may impair random
performance -and vice versa.
1. The seek policy is a hint; even if declared as a `must()` option, the
filesystem MAY ignore it.
1. The interpretation/implementation of a policy is a filesystem specific
behavior -and it may change with Hadoop releases and/or specific storage
subsystems.
1. If a policy is not recognized, the filesystem client MUST ignore it.
| Policy | Meaning |
|--------------|----------------------------------------------------------|
| `adaptive` | Any adaptive policy implemented by the store. |
| `default` | The default policy for this store. Generally "adaptive". |
| `random` | Optimize for random access. |
| `sequential` | Optimize for sequential access. |
| `vector` | The Vectored IO API is intended to be used. |
| `whole-file` | The whole file will be read. |
Choosing the wrong read policy for an input source may be inefficient.
A list of read policies MAY be supplied; the first one recognized/supported by
the filesystem SHALL be the one used. This allows for custom policies to be
supported, for example an `hbase-hfile` policy optimized for HBase HFiles.
The S3A and ABFS input streams both implement
the [IOStatisticsSource](iostatistics.html) API, and can be queried for their IO
Performance.
*Tip:* log the `toString()` value of input streams at `DEBUG`. The S3A and ABFS
Input Streams log read statistics, which can provide insight about whether reads
are being performed efficiently or not.
_Futher reading_
* [Linux fadvise()](https://linux.die.net/man/2/fadvise).
* [Windows `CreateFile()`](https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-createfilea#caching-behavior)
#### <a name="read.policy."></a> Read Policy `adaptive`
Try to adapt the seek policy to the read pattern of the application.
The `normal` policy of the S3A client and the sole policy supported by
the `wasb:` client are both adaptive -they assume sequential IO, but once a
backwards seek/positioned read call is made the stream switches to random IO.
Other filesystem implementations may wish to adopt similar strategies, and/or
extend the algorithms to detect forward seeks and/or switch from random to
sequential IO if that is considered more efficient.
Adaptive read policies are the absence of the ability to
declare the seek policy in the `open()` API, so requiring it to be declared, if
configurable, in the cluster/application configuration. However, the switch from
sequential to random seek policies may be exensive.
When applications explicitly set the `fs.option.openfile.read.policy` option, if
they know their read plan, they SHOULD declare which policy is most appropriate.
#### <a name="read.policy.default"></a> Read Policy ``
The default policy for the filesystem instance.
Implementation/installation-specific.
#### <a name="read.policy.sequential"></a> Read Policy `sequential`
Expect sequential reads from the first byte read to the end of the file/until
the stream is closed.
#### <a name="read.policy.random"></a> Read Policy `random`
Expect `seek()/read()` sequences, or use of `PositionedReadable`
or `ByteBufferPositionedReadable` APIs.
#### <a name="read.policy.vector"></a> Read Policy `vector`
This declares that the caller intends to use the Vectored read API of
[HADOOP-11867](https://issues.apache.org/jira/browse/HADOOP-11867)
_Add a high-performance vectored read API_.
This is a hint: it is not a requirement when using the API.
It does inform the implemenations that the stream should be
configured for optimal vectored IO performance, if such a
feature has been implemented.
It is *not* exclusive: the same stream may still be used for
classic `InputStream` and `PositionedRead` API calls.
Implementations SHOULD use the `random` read policy
with these operations.
#### <a name="read.policy.whole-file"></a> Read Policy `whole-file`
This declares that the whole file is to be read end-to-end; the file system client is free to enable
whatever strategies maximise performance for this. In particular, larger ranged reads/GETs can
deliver high bandwidth by reducing socket/TLS setup costs and providing a connection long-lived
enough for TCP flow control to determine the optimal download rate.
Strategies can include:
* Initiate an HTTP GET of the entire file in `openFile()` operation.
* Prefech data in large blocks, possibly in parallel read operations.
Applications which know that the entire file is to be read from an opened stream SHOULD declare this
read policy.
### <a name="openfile.length"></a> Option: `fs.option.openfile.length`
Declare the length of a file.
This can be used by clients to skip querying a remote store for the size
of/existence of a file when opening it, similar to declaring a file status
through the `withFileStatus()` option.
If supported by a filesystem connector, this option MUST be interpreted as
declaring the minimum length of the file:
1. If the value is negative, the option SHALL be considered unset.
2. It SHALL NOT be an error if the actual length of the file is greater than
this value.
3. `read()`, `seek()` and positioned read calls MAY use a position across/beyond
this length but below the actual length of the file. Implementations MAY
raise `EOFExceptions` in such cases, or they MAY return data.
If this option is used by the FileSystem implementation
*Implementor's Notes*
* A value of `fs.option.openfile.length` &lt; 0 MUST be rejected.
* If a file status is supplied along with a value in `fs.opt.openfile.length`;
the file status values take precedence.
### <a name="split.start"></a> Options: `fs.option.openfile.split.start` and `fs.option.openfile.split.end`
Declare the start and end of the split when a file has been split for processing
in pieces.
1. If a value is negative, the option SHALL be considered unset.
1. Filesystems MAY assume that the length of the file is greater than or equal
to the value of `fs.option.openfile.split.end`.
1. And that they MAY raise an exception if the client application reads past the
value set in `fs.option.openfile.split.end`.
1. The pair of options MAY be used to optimise the read plan, such as setting
the content range for GET requests, or using the split end as an implicit
declaration of the guaranteed minimum length of the file.
1. If both options are set, and the split start is declared as greater than the
split end, then the split start SHOULD just be reset to zero, rather than
rejecting the operation.
The split end value can provide a hint as to the end of the input stream. The
split start can be used to optimize any initial read offset for filesystem
clients.
*Note for implementors: applications will read past the end of a split when they
need to read to the end of a record/line which begins before the end of the
split.
Therefore clients MUST be allowed to `seek()`/`read()` past the length
set in `fs.option.openfile.split.end` if the file is actually longer
than that value.
## <a name="s3a"></a> S3A-specific options
The S3A Connector supports custom options for readahead and seek policy.
| Name | Type | Meaning |
|--------------------------------------|----------|-------------------------------------------------------------|
| `fs.s3a.readahead.range` | `long` | readahead range in bytes |
| `fs.s3a.input.async.drain.threshold` | `long` | threshold to switch to asynchronous draining of the stream |
| `fs.s3a.experimental.input.fadvise` | `String` | seek policy. Superceded by `fs.option.openfile.read.policy` |
If the option set contains a SQL statement in the `fs.s3a.select.sql` statement,
then the file is opened as an S3 Select query.
Consult the S3A documentation for more details.
## <a name="abfs"></a> ABFS-specific options
The ABFS Connector supports custom input stream options.
| Name | Type | Meaning |
|-----------------------------------|-----------|----------------------------------------------------|
| `fs.azure.buffered.pread.disable` | `boolean` | disable caching on the positioned read operations. |
Disables caching on data read through the [PositionedReadable](fsdatainputstream.html#PositionedReadable)
APIs.
Consult the ABFS Documentation for more details.
## <a name="examples"></a> Examples
#### Declaring seek policy and split limits when opening a file.
Here is an example from a proof of
concept `org.apache.parquet.hadoop.util.HadoopInputFile`
reader which uses a (nullable) file status and a split start/end.
The `FileStatus` value is always passed in -but if it is null, then the split
end is used to declare the length of the file.
```java
protected SeekableInputStream newStream(Path path, FileStatus stat,
long splitStart, long splitEnd)
throws IOException {
FutureDataInputStreamBuilder builder = fs.openFile(path)
.opt("fs.option.openfile.read.policy", "vector, random")
.withFileStatus(stat);
builder.opt("fs.option.openfile.split.start", splitStart);
builder.opt("fs.option.openfile.split.end", splitEnd);
CompletableFuture<FSDataInputStream> streamF = builder.build();
return HadoopStreams.wrap(FutureIO.awaitFuture(streamF));
}
```
As a result, whether driven directly by a file listing, or when opening a file
from a query plan of `(path, splitStart, splitEnd)`, there is no need to probe
the remote store for the length of the file. When working with remote object
stores, this can save tens to hundreds of milliseconds, even if such a probe is
done asynchronously.
If both the file length and the split end is set, then the file length MUST be
considered "more" authoritative, that is it really SHOULD be defining the file
length. If the split end is set, the caller MAY ot read past it.
The `CompressedSplitLineReader` can read past the end of a split if it is
partway through processing a compressed record. That is: it assumes an
incomplete record read means that the file length is greater than the split
length, and that it MUST read the entirety of the partially read record. Other
readers may behave similarly.
Therefore
1. File length as supplied in a `FileStatus` or in `fs.option.openfile.length`
SHALL set the strict upper limit on the length of a file
2. The split end as set in `fs.option.openfile.split.end` MUST be viewed as a
hint, rather than the strict end of the file.
### Opening a file with both standard and non-standard options
Standard and non-standard options MAY be combined in the same `openFile()`
operation.
```java
Future<FSDataInputStream> f = openFile(path)
.must("fs.option.openfile.read.policy", "random, adaptive")
.opt("fs.s3a.readahead.range", 1024 * 1024)
.build();
FSDataInputStream is = f.get();
```
The option set in `must()` MUST be understood, or at least recognized and
ignored by all filesystems. In this example, S3A-specific option MAY be
ignored by all other filesystem clients.
### Opening a file with older releases
Not all hadoop releases recognize the `fs.option.openfile.read.policy` option.
The option can be safely used in application code if it is added via the `opt()`
builder argument, as it will be treated as an unknown optional key which can
then be discarded.
```java
Future<FSDataInputStream> f = openFile(path)
.opt("fs.option.openfile.read.policy", "vector, random, adaptive")
.build();
FSDataInputStream is = f.get();
```
*Note 1* if the option name is set by a reference to a constant in
`org.apache.hadoop.fs.Options.OpenFileOptions`, then the program will not link
against versions of Hadoop without the specific option. Therefore for resilient
linking against older releases -use a copy of the value.
*Note 2* as option validation is performed in the FileSystem connector,
a third-party connector designed to work with multiple hadoop versions
MAY NOT support the option.
### Passing options in to MapReduce
Hadoop MapReduce will automatically read MR Job Options with the prefixes
`mapreduce.job.input.file.option.` and `mapreduce.job.input.file.must.`
prefixes, and apply these values as `.opt()` and `must()` respectively, after
remove the mapreduce-specific prefixes.
This makes passing options in to MR jobs straightforward. For example, to
declare that a job should read its data using random IO:
```java
JobConf jobConf = (JobConf) job.getConfiguration()
jobConf.set(
"mapreduce.job.input.file.option.fs.option.openfile.read.policy",
"random");
```
### MapReduce input format propagating options
An example of a record reader passing in options to the file it opens.
```java
public void initialize(InputSplit genericSplit,
TaskAttemptContext context) throws IOException {
FileSplit split = (FileSplit)genericSplit;
Configuration job = context.getConfiguration();
start = split.getStart();
end = start + split.getLength();
Path file = split.getPath();
// open the file and seek to the start of the split
FutureDataInputStreamBuilder builder =
file.getFileSystem(job).openFile(file);
// the start and end of the split may be used to build
// an input strategy.
builder.opt("fs.option.openfile.split.start", start);
builder.opt("fs.option.openfile.split.end", end);
FutureIO.propagateOptions(builder, job,
"mapreduce.job.input.file.option",
"mapreduce.job.input.file.must");
fileIn = FutureIO.awaitFuture(builder.build());
fileIn.seek(start)
/* Rest of the operation on the opened stream */
}
```
### `FileContext.openFile`
From `org.apache.hadoop.fs.AvroFSInput`; a file is opened with sequential input.
Because the file length has already been probed for, the length is passd down
```java
public AvroFSInput(FileContext fc, Path p) throws IOException {
FileStatus status = fc.getFileStatus(p);
this.len = status.getLen();
this.stream = awaitFuture(fc.openFile(p)
.opt("fs.option.openfile.read.policy",
"sequential")
.opt("fs.option.openfile.length",
Long.toString(status.getLen()))
.build());
fc.open(p);
}
```
In this example, the length is passed down as a string (via `Long.toString()`)
rather than directly as a long. This is to ensure that the input format will
link against versions of $Hadoop which do not have the
`opt(String, long)` and `must(String, long)` builder parameters. Similarly, the
values are passed as optional, so that if unrecognized the application will
still succeed.
### Example: reading a whole file
This is from `org.apache.hadoop.util.JsonSerialization`.
Its `load(FileSystem, Path, FileStatus)` method
* declares the whole file is to be read end to end.
* passes down the file status
```java
public T load(FileSystem fs,
Path path,
status)
throws IOException {
try (FSDataInputStream dataInputStream =
awaitFuture(fs.openFile(path)
.opt("fs.option.openfile.read.policy", "whole-file")
.withFileStatus(status)
.build())) {
return fromJsonStream(dataInputStream);
} catch (JsonProcessingException e) {
throw new PathIOException(path.toString(),
"Failed to read JSON file " + e, e);
}
}
```
*Note:* : in Hadoop 3.3.2 and earlier, the `withFileStatus(status)` call
required a non-null parameter; this has since been relaxed.
For maximum compatibility across versions, only invoke the method
when the file status is known to be non-null.

1
hadoop-common-project/hadoop-common/src/site/markdown/filesystem/index.md
View File

@ -41,3 +41,4 @@ HDFS as these are commonly expected by Hadoop client applications.
2. [Extending the specification and its tests](extending.html)
1. [Uploading a file using Multiple Parts](multipartuploader.html)
1. [IOStatistics](iostatistics.html)
1. [openFile()](openfile.html).

122
hadoop-common-project/hadoop-common/src/site/markdown/filesystem/openfile.md Normal file
View File

@ -0,0 +1,122 @@
<!---
Licensed 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. See accompanying LICENSE file.
-->
# `FileSystem.openFile()`/`FileContext.openFile()`
This is a method provided by both FileSystem and FileContext for
advanced file opening options and, where implemented,
an asynchrounous/lazy opening of a file.
Creates a builder to open a file, supporting options
both standard and filesystem specific. The return
value of the `build()` call is a `Future<FSDataInputStream>`,
which must be waited on. The file opening may be
asynchronous, and it may actually be postponed (including
permission/existence checks) until reads are actually
performed.
This API call was added to `FileSystem` and `FileContext` in
Hadoop 3.3.0; it was tuned in Hadoop 3.3.1 as follows.
* Added `opt(key, long)` and `must(key, long)`.
* Declared that `withFileStatus(null)` is allowed.
* Declared that `withFileStatus(status)` only checks
the filename of the path, not the full path.
This is needed to support passthrough/mounted filesystems.
* Added standard option keys.
### <a name="openfile_path_"></a> `FutureDataInputStreamBuilder openFile(Path path)`
Creates a [`FutureDataInputStreamBuilder`](fsdatainputstreambuilder.html)
to construct a operation to open the file at `path` for reading.
When `build()` is invoked on the returned `FutureDataInputStreamBuilder` instance,
the builder parameters are verified and
`FileSystem.openFileWithOptions(Path, OpenFileParameters)` or
`AbstractFileSystem.openFileWithOptions(Path, OpenFileParameters)` invoked.
These protected methods returns a `CompletableFuture<FSDataInputStream>`
which, when its `get()` method is called, either returns an input
stream of the contents of opened file, or raises an exception.
The base implementation of the `FileSystem.openFileWithOptions(PathHandle, OpenFileParameters)`
ultimately invokes `FileSystem.open(Path, int)`.
Thus the chain `FileSystem.openFile(path).build().get()` has the same preconditions
and postconditions as `FileSystem.open(Path p, int bufferSize)`
However, there is one difference which implementations are free to
take advantage of:
The returned stream MAY implement a lazy open where file non-existence or
access permission failures may not surface until the first `read()` of the
actual data.
This saves network IO on object stores.
The `openFile()` operation MAY check the state of the filesystem during its
invocation, but as the state of the filesystem may change between this call and
the actual `build()` and `get()` operations, this file-specific
preconditions (file exists, file is readable, etc) MUST NOT be checked here.
FileSystem implementations which do not implement `open(Path, int)`
MAY postpone raising an `UnsupportedOperationException` until either the
`FutureDataInputStreamBuilder.build()` or the subsequent `get()` call,
else they MAY fail fast in the `openFile()` call.
Consult [`FutureDataInputStreamBuilder`](fsdatainputstreambuilder.html) for details
on how to use the builder, and for standard options which may be passed in.
### <a name="openfile_pathhandle_"></a> `FutureDataInputStreamBuilder openFile(PathHandle)`
Creates a [`FutureDataInputStreamBuilder`](fsdatainputstreambuilder.html)
to construct a operation to open the file identified by the given `PathHandle` for reading.
If implemented by a filesystem, the semantics of [`openFile(Path)`](#openfile_path_)
Thus the chain `openFile(pathhandle).build().get()` has the same preconditions and postconditions
as `open(Pathhandle, int)`
FileSystem implementations which do not implement `open(PathHandle handle, int bufferSize)`
MAY postpone raising an `UnsupportedOperationException` until either the
`FutureDataInputStreamBuilder.build()` or the subsequent `get()` call, else they MAY fail fast in
the `openFile(PathHandle)` call.
The base implementation raises this exception in the `build()` operation; other implementations
SHOULD copy this.
### Implementors notes
The base implementation of `openFileWithOptions()` actually executes
the `open(path)` operation synchronously, yet still returns the result
or any failures in the `CompletableFuture<>`, so as to provide a consistent
lifecycle across all filesystems.
Any filesystem client where the time to open a file may be significant SHOULD
execute it asynchronously by submitting the operation in some executor/thread
pool. This is particularly recommended for object stores and other filesystems
likely to be accessed over long-haul connections.
Arbitrary filesystem-specific options MAY be supported; these MUST
be prefixed with either the filesystem schema, e.g. `hdfs.`
or in the `fs.SCHEMA` format as normal configuration settings `fs.hdfs`. The
latter style allows the same configuration option to be used for both
filesystem configuration and file-specific configuration.
It SHOULD be possible to always open a file without specifying any options,
so as to present a consistent model to users. However, an implementation MAY
opt to require one or more mandatory options to be set.
The returned stream may perform "lazy" evaluation of file access. This is
relevant for object stores where the probes for existence are expensive, and,
even with an asynchronous open, may be considered needless.

2
hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/contract/AbstractContractMultipartUploaderTest.java
View File

@ -50,11 +50,11 @@ import org.apache.hadoop.test.LambdaTestUtils;
import org.apache.hadoop.util.DurationInfo;
import static org.apache.hadoop.fs.contract.ContractTestUtils.verifyPathExists;
import static org.apache.hadoop.fs.impl.FutureIOSupport.awaitFuture;
import static org.apache.hadoop.fs.statistics.IOStatisticsLogging.ioStatisticsSourceToString;
import static org.apache.hadoop.io.IOUtils.cleanupWithLogger;
import static org.apache.hadoop.test.LambdaTestUtils.eventually;
import static org.apache.hadoop.test.LambdaTestUtils.intercept;
import static org.apache.hadoop.util.functional.FutureIO.awaitFuture;
/**
* Tests of multipart uploads.

80
hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/contract/AbstractContractOpenTest.java
View File

@ -30,14 +30,18 @@ import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.FutureDataInputStreamBuilder;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.impl.FutureIOSupport;
import org.apache.hadoop.io.IOUtils;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_BUFFER_SIZE;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_READ_POLICY;
import static org.apache.hadoop.fs.Options.OpenFileOptions.FS_OPTION_OPENFILE_LENGTH;
import static org.apache.hadoop.fs.contract.ContractTestUtils.compareByteArrays;
import static org.apache.hadoop.fs.contract.ContractTestUtils.createFile;
import static org.apache.hadoop.fs.contract.ContractTestUtils.dataset;
import static org.apache.hadoop.fs.contract.ContractTestUtils.touch;
import static org.apache.hadoop.test.LambdaTestUtils.intercept;
import static org.apache.hadoop.test.LambdaTestUtils.interceptFuture;
import static org.apache.hadoop.util.functional.FutureIO.awaitFuture;
import org.junit.Test;
@ -232,7 +236,7 @@ public abstract class AbstractContractOpenTest
getFileSystem().openFile(path("testAwaitFutureFailToFNFE"))
.opt("fs.test.something", true);
intercept(FileNotFoundException.class,
() -> FutureIOSupport.awaitFuture(builder.build()));
() -> awaitFuture(builder.build()));
}
@Test
@ -242,7 +246,7 @@ public abstract class AbstractContractOpenTest
getFileSystem().openFile(path("testAwaitFutureFailToFNFE"))
.opt("fs.test.something", true);
intercept(FileNotFoundException.class,
() -> FutureIOSupport.awaitFuture(builder.build(),
() -> awaitFuture(builder.build(),
10, TimeUnit.DAYS));
}
@ -250,7 +254,7 @@ public abstract class AbstractContractOpenTest
public void testOpenFileExceptionallyTranslating() throws Throwable {
describe("openFile missing file chains into exceptionally()");
CompletableFuture<FSDataInputStream> f = getFileSystem()
.openFile(path("testOpenFileUnknownOption")).build();
.openFile(path("testOpenFileExceptionallyTranslating")).build();
interceptFuture(RuntimeException.class,
"exceptionally",
f.exceptionally(ex -> {
@ -262,11 +266,12 @@ public abstract class AbstractContractOpenTest
public void testChainedFailureAwaitFuture() throws Throwable {
describe("await Future handles chained failures");
CompletableFuture<FSDataInputStream> f = getFileSystem()
.openFile(path("testOpenFileUnknownOption"))
.openFile(path("testChainedFailureAwaitFuture"))
.withFileStatus(null)
.build();
intercept(RuntimeException.class,
"exceptionally",
() -> FutureIOSupport.awaitFuture(
() -> awaitFuture(
f.exceptionally(ex -> {
throw new RuntimeException("exceptionally", ex);
})));
@ -280,13 +285,34 @@ public abstract class AbstractContractOpenTest
int len = 4096;
createFile(fs, path, true,
dataset(len, 0x40, 0x80));
FileStatus st = fs.getFileStatus(path);
CompletableFuture<Long> readAllBytes = fs.openFile(path)
.withFileStatus(fs.getFileStatus(path))
.withFileStatus(st)
.build()
.thenApply(ContractTestUtils::readStream);
assertEquals("Wrong number of bytes read value",
len,
(long) readAllBytes.get());
// now reattempt with a new FileStatus and a different path
// other than the final name element
// implementations MUST use path in openFile() call
FileStatus st2 = new FileStatus(
len, false,
st.getReplication(),
st.getBlockSize(),
st.getModificationTime(),
st.getAccessTime(),
st.getPermission(),
st.getOwner(),
st.getGroup(),
new Path("gopher:///localhost:/" + path.getName()));
assertEquals("Wrong number of bytes read value",
len,
(long) fs.openFile(path)
.withFileStatus(st2)
.build()
.thenApply(ContractTestUtils::readStream)
.get());
}
@Test
@ -298,17 +324,47 @@ public abstract class AbstractContractOpenTest
dataset(4, 0x40, 0x80));
CompletableFuture<FSDataInputStream> future = fs.openFile(path).build();
AtomicBoolean accepted = new AtomicBoolean(false);
future.thenAcceptAsync(i -> accepted.set(true)).get();
future.thenApply(stream -> {
accepted.set(true);
return stream;
}).get().close();
assertTrue("async accept operation not invoked",
accepted.get());
}
/**
* Open a file with a null status, and the length
* passed in as an opt() option (along with sequential IO).
* The file is opened, the data read, and it must match
* the source data.
* opt() is used so that integration testing with external
* filesystem connectors will downgrade if the option is not
* recognized.
*/
@Test
public void testOpenFileNullStatus() throws Throwable {
describe("use openFile() with a null status");
public void testOpenFileNullStatusButFileLength() throws Throwable {
describe("use openFile() with a null status and expect the status to be"
+ " ignored. block size, fadvise and length are passed in as"
+ " opt() options");
Path path = path("testOpenFileNullStatus");
intercept(NullPointerException.class,
() -> getFileSystem().openFile(path).withFileStatus(null));
FileSystem fs = getFileSystem();
int len = 4;
byte[] result = new byte[len];
byte[] dataset = dataset(len, 0x40, 0x80);
createFile(fs, path, true,
dataset);
CompletableFuture<FSDataInputStream> future = fs.openFile(path)
.withFileStatus(null)
.opt(FS_OPTION_OPENFILE_READ_POLICY,
"unknown, sequential, random")
.opt(FS_OPTION_OPENFILE_BUFFER_SIZE, 32768)
.opt(FS_OPTION_OPENFILE_LENGTH, len)
.build();
try (FSDataInputStream in = future.get()) {
in.readFully(result);
}
compareByteArrays(dataset, result, len);
}
}

13
hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/contract/ContractTestUtils.java
View File

@ -1642,17 +1642,22 @@ public class ContractTestUtils extends Assert {
/**
* Read a whole stream; downgrades an IOE to a runtime exception.
* Closes the stream afterwards.
* @param in input
* @return the number of bytes read.
* @throws AssertionError on any IOException
*/
public static long readStream(InputStream in) {
long count = 0;
try {
long count = 0;
while (read(in) >= 0) {
count++;
while (read(in) >= 0) {
count++;
}
return count;
} finally {
IOUtils.cleanupWithLogger(LOG, in);
}
return count;
}

20
hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/statistics/IOStatisticAssertions.java
View File

@ -36,6 +36,8 @@ import org.assertj.core.api.ObjectAssert;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import static org.apache.hadoop.fs.statistics.StoreStatisticNames.SUFFIX_MAX;
import static org.apache.hadoop.fs.statistics.StoreStatisticNames.SUFFIX_MIN;
import static org.assertj.core.api.Assertions.assertThat;
/**
@ -347,6 +349,24 @@ public final class IOStatisticAssertions {
verifyStatisticsNotNull(stats).maximums());
}
/**
* Assert that a duration is within a given minimum/maximum range.
* @param stats statistics source
* @param key statistic key without any suffix
* @param min minimum statistic must be equal to or greater than this.
* @param max maximum statistic must be equal to or less than this.
*/
public static void assertDurationRange(
final IOStatistics stats,
final String key,
final long min,
final long max) {
assertThatStatisticMinimum(stats, key + SUFFIX_MIN)
.isGreaterThanOrEqualTo(min);
assertThatStatisticMaximum(stats, key + SUFFIX_MAX)
.isLessThanOrEqualTo(max);
}
/**
* Start an assertion chain on
* a required mean statistic.

3
hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/statistics/TestDurationTracking.java
View File

@ -30,7 +30,6 @@ import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.fs.impl.FutureIOSupport;
import org.apache.hadoop.fs.statistics.impl.IOStatisticsStore;
import org.apache.hadoop.test.AbstractHadoopTestBase;
import org.apache.hadoop.util.functional.FunctionRaisingIOE;
@ -276,7 +275,7 @@ public class TestDurationTracking extends AbstractHadoopTestBase {
*/
@Test
public void testDurationThroughEval() throws Throwable {
CompletableFuture<Object> eval = FutureIOSupport.eval(
CompletableFuture<Object> eval = FutureIO.eval(
trackDurationOfOperation(stats, REQUESTS, () -> {
sleepf(100);
throw new FileNotFoundException("oops");