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HADOOP-17250 Lot of short reads can be merged with readahead. (#3110)

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Introducing fs.azure.readahead.range parameter which can be set by the user.
Data will be populated in buffer for random reads as well which leads to fewer
remote calls.

This patch also changes the seek implementation to perform a lazy seek. The
actual seek is done when a read is initiated and data is not present in the buffer else
data is returned from the buffer thus reducing the number of remote storage calls.

Contributed By: Mukund Thakur

Change-Id: Ib920eedd0087caa150afa4d4c23e89df56b29e83
This commit is contained in:
Mukund Thakur 2021-07-05 15:49:13 +05:30 committed by Steve Loughran
parent 2d56335a3d
commit e8f9af6f2a
No known key found for this signature in database
GPG Key ID: D22CF846DBB162A0
10 changed files with 328 additions and 23 deletions
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10
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/AbfsConfiguration.java
View File

@ -121,6 +121,12 @@ public class AbfsConfiguration{
DefaultValue = DEFAULT_READ_BUFFER_SIZE)
private int readBufferSize;
@IntegerConfigurationValidatorAnnotation(ConfigurationKey = AZURE_READ_AHEAD_RANGE,
MinValue = MIN_BUFFER_SIZE,
MaxValue = MAX_BUFFER_SIZE,
DefaultValue = DEFAULT_READ_AHEAD_RANGE)
private int readAheadRange;
@IntegerConfigurationValidatorAnnotation(ConfigurationKey = AZURE_MIN_BACKOFF_INTERVAL,
DefaultValue = DEFAULT_MIN_BACKOFF_INTERVAL)
private int minBackoffInterval;
@ -878,6 +884,10 @@ public SASTokenProvider getSASTokenProvider() throws AzureBlobFileSystemExceptio
}
}
public int getReadAheadRange() {
return this.readAheadRange;
}
int validateInt(Field field) throws IllegalAccessException, InvalidConfigurationValueException {
IntegerConfigurationValidatorAnnotation validator = field.getAnnotation(IntegerConfigurationValidatorAnnotation.class);
String value = get(validator.ConfigurationKey());

1
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/AzureBlobFileSystemStore.java
View File

@ -697,6 +697,7 @@ private AbfsInputStreamContext populateAbfsInputStreamContext(
.withTolerateOobAppends(abfsConfiguration.getTolerateOobAppends())
.withReadSmallFilesCompletely(abfsConfiguration.readSmallFilesCompletely())
.withOptimizeFooterRead(abfsConfiguration.optimizeFooterRead())
.withReadAheadRange(abfsConfiguration.getReadAheadRange())
.withStreamStatistics(new AbfsInputStreamStatisticsImpl())
.withShouldReadBufferSizeAlways(
abfsConfiguration.shouldReadBufferSizeAlways())

8
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/constants/ConfigurationKeys.java
View File

@ -68,6 +68,14 @@ public final class ConfigurationKeys {
public static final String AZURE_READ_BUFFER_SIZE = "fs.azure.read.request.size";
public static final String AZURE_READ_SMALL_FILES_COMPLETELY = "fs.azure.read.smallfilescompletely";
public static final String AZURE_READ_OPTIMIZE_FOOTER_READ = "fs.azure.read.optimizefooterread";
/**
* Read ahead range parameter which can be set by user.
* Default value is {@link FileSystemConfigurations#DEFAULT_READ_AHEAD_RANGE}.
* This might reduce number of calls to remote as next requested
* data could already be present in buffer {@value}.
*/
public static final String AZURE_READ_AHEAD_RANGE = "fs.azure.readahead.range";
public static final String AZURE_BLOCK_SIZE_PROPERTY_NAME = "fs.azure.block.size";
public static final String AZURE_BLOCK_LOCATION_HOST_PROPERTY_NAME = "fs.azure.block.location.impersonatedhost";
public static final String AZURE_CONCURRENT_CONNECTION_VALUE_OUT = "fs.azure.concurrentRequestCount.out";

1
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/constants/FileSystemConfigurations.java
View File

@ -62,6 +62,7 @@ public final class FileSystemConfigurations {
public static final boolean DEFAULT_OPTIMIZE_FOOTER_READ = false;
public static final boolean DEFAULT_ALWAYS_READ_BUFFER_SIZE = false;
public static final int DEFAULT_READ_AHEAD_BLOCK_SIZE = 4 * ONE_MB;
public static final int DEFAULT_READ_AHEAD_RANGE = 64 * ONE_KB; // 64 KB
public static final int MIN_BUFFER_SIZE = 16 * ONE_KB; // 16 KB
public static final int MAX_BUFFER_SIZE = 100 * ONE_MB; // 100 MB
public static final long MAX_AZURE_BLOCK_SIZE = 256 * 1024 * 1024L; // changing default abfs blocksize to 256MB

66
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsInputStream.java
View File

@ -75,6 +75,8 @@ public class AbfsInputStream extends FSInputStream implements CanUnbuffer,
* @see #read(long, byte[], int, int)
*/
private final boolean bufferedPreadDisabled;
// User configured size of read ahead.
private final int readAheadRange;
private boolean firstRead = true;
// SAS tokens can be re-used until they expire
@ -103,6 +105,11 @@ public class AbfsInputStream extends FSInputStream implements CanUnbuffer,
private final AbfsInputStreamContext context;
private IOStatistics ioStatistics;
/**
* This is the actual position within the object, used by
* lazy seek to decide whether to seek on the next read or not.
*/
private long nextReadPos;
public AbfsInputStream(
final AbfsClient client,
@ -119,6 +126,7 @@ public AbfsInputStream(
this.readAheadQueueDepth = abfsInputStreamContext.getReadAheadQueueDepth();
this.tolerateOobAppends = abfsInputStreamContext.isTolerateOobAppends();
this.eTag = eTag;
this.readAheadRange = abfsInputStreamContext.getReadAheadRange();
this.readAheadEnabled = true;
this.alwaysReadBufferSize
= abfsInputStreamContext.shouldReadBufferSizeAlways();
@ -207,6 +215,28 @@ public synchronized int read(final byte[] b, final int off, final int len) throw
}
incrementReadOps();
do {
// limit is the maximum amount of data present in buffer.
// fCursor is the current file pointer. Thus maximum we can
// go back and read from buffer is fCursor - limit.
// There maybe case that we read less than requested data.
long filePosAtStartOfBuffer = fCursor - limit;
if (nextReadPos >= filePosAtStartOfBuffer && nextReadPos <= fCursor) {
// Determining position in buffer from where data is to be read.
bCursor = (int) (nextReadPos - filePosAtStartOfBuffer);
// When bCursor == limit, buffer will be filled again.
// So in this case we are not actually reading from buffer.
if (bCursor != limit && streamStatistics != null) {
streamStatistics.seekInBuffer();
}
} else {
// Clearing the buffer and setting the file pointer
// based on previous seek() call.
fCursor = nextReadPos;
limit = 0;
bCursor = 0;
}
if (shouldReadFully()) {
lastReadBytes = readFileCompletely(b, currentOff, currentLen);
} else if (shouldReadLastBlock()) {
@ -265,9 +295,13 @@ private int readOneBlock(final byte[] b, final int off, final int len) throws IO
} else {
// Enable readAhead when reading sequentially
if (-1 == fCursorAfterLastRead || fCursorAfterLastRead == fCursor || b.length >= bufferSize) {
LOG.debug("Sequential read with read ahead size of {}", bufferSize);
bytesRead = readInternal(fCursor, buffer, 0, bufferSize, false);
} else {
bytesRead = readInternal(fCursor, buffer, 0, b.length, true);
// Enabling read ahead for random reads as well to reduce number of remote calls.
int lengthWithReadAhead = Math.min(b.length + readAheadRange, bufferSize);
LOG.debug("Random read with read ahead size of {}", lengthWithReadAhead);
bytesRead = readInternal(fCursor, buffer, 0, lengthWithReadAhead, true);
}
}
if (firstRead) {
@ -401,6 +435,7 @@ private int copyToUserBuffer(byte[] b, int off, int len){
int bytesToRead = min(len, bytesRemaining);
System.arraycopy(buffer, bCursor, b, off, bytesToRead);
bCursor += bytesToRead;
nextReadPos += bytesToRead;
if (statistics != null) {
statistics.incrementBytesRead(bytesToRead);
}
@ -481,13 +516,13 @@ int readRemote(long position, byte[] b, int offset, int length) throws IOExcepti
final AbfsRestOperation op;
AbfsPerfTracker tracker = client.getAbfsPerfTracker();
try (AbfsPerfInfo perfInfo = new AbfsPerfInfo(tracker, "readRemote", "read")) {
if (streamStatistics != null) {
streamStatistics.remoteReadOperation();
}
LOG.trace("Trigger client.read for path={} position={} offset={} length={}", path, position, offset, length);
op = client.read(path, position, b, offset, length,
tolerateOobAppends ? "*" : eTag, cachedSasToken.get());
cachedSasToken.update(op.getSasToken());
if (streamStatistics != null) {
streamStatistics.remoteReadOperation();
}
LOG.debug("issuing HTTP GET request params position = {} b.length = {} "
+ "offset = {} length = {}", position, b.length, offset, length);
perfInfo.registerResult(op.getResult()).registerSuccess(true);
@ -545,21 +580,9 @@ public synchronized void seek(long n) throws IOException {
streamStatistics.seek(n, fCursor);
}
if (n>=fCursor-limit && n<=fCursor) { // within buffer
bCursor = (int) (n-(fCursor-limit));
if (streamStatistics != null) {
streamStatistics.seekInBuffer();
}
return;
}
// next read will read from here
fCursor = n;
LOG.debug("set fCursor to {}", fCursor);
//invalidate buffer
limit = 0;
bCursor = 0;
nextReadPos = n;
LOG.debug("set nextReadPos to {}", nextReadPos);
}
@Override
@ -630,7 +653,7 @@ public synchronized long getPos() throws IOException {
if (closed) {
throw new IOException(FSExceptionMessages.STREAM_IS_CLOSED);
}
return fCursor - limit + bCursor;
return nextReadPos < 0 ? 0 : nextReadPos;
}
/**
@ -696,6 +719,11 @@ byte[] getBuffer() {
return buffer;
}
@VisibleForTesting
public int getReadAheadRange() {
return readAheadRange;
}
@VisibleForTesting
protected void setCachedSasToken(final CachedSASToken cachedSasToken) {
this.cachedSasToken = cachedSasToken;

15
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsInputStreamContext.java
View File

@ -20,6 +20,7 @@
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.thirdparty.com.google.common.base.Preconditions;
/**
* Class to hold extra input stream configs.
@ -38,6 +39,8 @@ public class AbfsInputStreamContext extends AbfsStreamContext {
private int readAheadBlockSize;
private int readAheadRange;
private AbfsInputStreamStatistics streamStatistics;
private boolean readSmallFilesCompletely;
@ -69,6 +72,12 @@ public AbfsInputStreamContext withTolerateOobAppends(
return this;
}
public AbfsInputStreamContext withReadAheadRange(
final int readAheadRange) {
this.readAheadRange = readAheadRange;
return this;
}
public AbfsInputStreamContext withStreamStatistics(
final AbfsInputStreamStatistics streamStatistics) {
this.streamStatistics = streamStatistics;
@ -115,6 +124,8 @@ public AbfsInputStreamContext build() {
readAheadBlockSize = readBufferSize;
}
// Validation of parameters to be done here.
Preconditions.checkArgument(readAheadRange > 0,
"Read ahead range should be greater than 0");
return this;
}
@ -130,6 +141,10 @@ public boolean isTolerateOobAppends() {
return tolerateOobAppends;
}
public int getReadAheadRange() {
return readAheadRange;
}
public AbfsInputStreamStatistics getStreamStatistics() {
return streamStatistics;
}

6
hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/ITestAbfsInputStreamStatistics.java
View File

@ -127,6 +127,7 @@ public void testSeekStatistics() throws IOException {
*/
for (int i = 0; i < OPERATIONS; i++) {
in.seek(0);
in.read();
in.seek(ONE_MB);
}
@ -155,7 +156,7 @@ public void testSeekStatistics() throws IOException {
* are in buffer.
*
* seekInBuffer - Since all seeks were in buffer, the seekInBuffer
* would be equal to 2 * OPERATIONS.
* would be equal to OPERATIONS.
*
*/
assertEquals("Mismatch in seekOps value", 2 * OPERATIONS,
@ -168,7 +169,7 @@ public void testSeekStatistics() throws IOException {
OPERATIONS * ONE_MB, stats.getBytesBackwardsOnSeek());
assertEquals("Mismatch in bytesSkippedOnSeek value",
0, stats.getBytesSkippedOnSeek());
assertEquals("Mismatch in seekInBuffer value", 2 * OPERATIONS,
assertEquals("Mismatch in seekInBuffer value", OPERATIONS,
stats.getSeekInBuffer());
in.close();
@ -260,6 +261,7 @@ public void testWithNullStreamStatistics() throws IOException {
.withReadBufferSize(getConfiguration().getReadBufferSize())
.withReadAheadQueueDepth(getConfiguration().getReadAheadQueueDepth())
.withStreamStatistics(null)
.withReadAheadRange(getConfiguration().getReadAheadRange())
.build();
AbfsOutputStream out = null;

2
hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/TestAbfsConfigurationFieldsValidation.java
View File

@ -34,6 +34,7 @@
import org.apache.hadoop.fs.azurebfs.utils.Base64;
import static org.apache.hadoop.fs.azurebfs.constants.ConfigurationKeys.FS_AZURE_SSL_CHANNEL_MODE_KEY;
import static org.apache.hadoop.fs.azurebfs.constants.FileSystemConfigurations.DEFAULT_READ_AHEAD_RANGE;
import static org.apache.hadoop.fs.azurebfs.constants.FileSystemConfigurations.DEFAULT_READ_BUFFER_SIZE;
import static org.apache.hadoop.fs.azurebfs.constants.FileSystemConfigurations.DEFAULT_WRITE_BUFFER_SIZE;
import static org.apache.hadoop.fs.azurebfs.constants.FileSystemConfigurations.DEFAULT_MAX_RETRY_ATTEMPTS;
@ -141,6 +142,7 @@ public void testConfigServiceImplAnnotatedFieldsInitialized() throws Exception {
assertEquals(DEFAULT_MAX_RETRY_ATTEMPTS, abfsConfiguration.getMaxIoRetries());
assertEquals(MAX_AZURE_BLOCK_SIZE, abfsConfiguration.getAzureBlockSize());
assertEquals(AZURE_BLOCK_LOCATION_HOST_DEFAULT, abfsConfiguration.getAzureBlockLocationHost());
assertEquals(DEFAULT_READ_AHEAD_RANGE, abfsConfiguration.getReadAheadRange());
}
@Test

238
hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/contract/ITestAbfsFileSystemContractSeek.java
View File

@ -18,10 +18,27 @@
package org.apache.hadoop.fs.azurebfs.contract;
import java.io.IOException;
import java.util.concurrent.CompletableFuture;
import org.assertj.core.api.Assertions;
import org.junit.Test;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.azurebfs.services.AbfsInputStream;
import org.apache.hadoop.fs.azurebfs.services.AbfsInputStreamStatisticsImpl;
import org.apache.hadoop.fs.contract.AbstractContractSeekTest;
import org.apache.hadoop.fs.contract.AbstractFSContract;
import static org.apache.hadoop.fs.azurebfs.constants.ConfigurationKeys.AZURE_READ_AHEAD_RANGE;
import static org.apache.hadoop.fs.azurebfs.constants.ConfigurationKeys.AZURE_READ_BUFFER_SIZE;
import static org.apache.hadoop.fs.azurebfs.constants.FileSystemConfigurations.MIN_BUFFER_SIZE;
import static org.apache.hadoop.fs.contract.ContractTestUtils.createFile;
import static org.apache.hadoop.fs.contract.ContractTestUtils.dataset;
import static org.apache.hadoop.fs.impl.FutureIOSupport.awaitFuture;
/**
* Contract test for seek operation.
*/
@ -29,6 +46,8 @@ public class ITestAbfsFileSystemContractSeek extends AbstractContractSeekTest{
private final boolean isSecure;
private final ABFSContractTestBinding binding;
private static final byte[] BLOCK = dataset(100 * 1024, 0, 255);
public ITestAbfsFileSystemContractSeek() throws Exception {
binding = new ABFSContractTestBinding();
this.isSecure = binding.isSecureMode();
@ -47,6 +66,225 @@ protected Configuration createConfiguration() {
@Override
protected AbstractFSContract createContract(final Configuration conf) {
conf.setInt(AZURE_READ_AHEAD_RANGE, MIN_BUFFER_SIZE);
conf.setInt(AZURE_READ_BUFFER_SIZE, MIN_BUFFER_SIZE);
return new AbfsFileSystemContract(conf, isSecure);
}
/**
* Test verifies if the data is read correctly
* when {@code ConfigurationKeys#AZURE_READ_AHEAD_RANGE} is set.
* Reason for not breaking this test into smaller parts is we
* really want to simulate lot of forward and backward seeks
* similar to real production use case.
*/
@Test
public void testSeekAndReadWithReadAhead() throws IOException {
describe(" Testing seek and read with read ahead "
+ "enabled for random reads");
Path testSeekFile = path(getMethodName() + "bigseekfile.txt");
createDataSet(testSeekFile);
try (FSDataInputStream in = getFileSystem().open(testSeekFile)) {
AbfsInputStream inStream = ((AbfsInputStream) in.getWrappedStream());
AbfsInputStreamStatisticsImpl streamStatistics =
(AbfsInputStreamStatisticsImpl) inStream.getStreamStatistics();
assertEquals(String.format("Value of %s is not set correctly", AZURE_READ_AHEAD_RANGE),
MIN_BUFFER_SIZE, inStream.getReadAheadRange());
long remoteReadOperationsOldVal = streamStatistics.getRemoteReadOperations();
Assertions.assertThat(remoteReadOperationsOldVal)
.describedAs("Number of remote read ops should be 0 "
+ "before any read call is made")
.isEqualTo(0);
// Test read at first position. Remote read.
Assertions.assertThat(inStream.getPos())
.describedAs("First call to getPos() should return 0")
.isEqualTo(0);
assertDataAtPos(0, (byte) in.read());
assertSeekBufferStats(0, streamStatistics.getSeekInBuffer());
long remoteReadOperationsNewVal = streamStatistics.getRemoteReadOperations();
assertIncrementInRemoteReadOps(remoteReadOperationsOldVal,
remoteReadOperationsNewVal);
remoteReadOperationsOldVal = remoteReadOperationsNewVal;
// Seeking just before read ahead range. Read from buffer.
int newSeek = inStream.getReadAheadRange() - 1;
in.seek(newSeek);
assertGetPosition(newSeek, in.getPos());
assertDataAtPos(newSeek, (byte) in.read());
assertSeekBufferStats(1, streamStatistics.getSeekInBuffer());
remoteReadOperationsNewVal = streamStatistics.getRemoteReadOperations();
assertNoIncrementInRemoteReadOps(remoteReadOperationsOldVal,
remoteReadOperationsNewVal);
remoteReadOperationsOldVal = remoteReadOperationsNewVal;
// Seeking boundary of read ahead range. Read from buffer manager.
newSeek = inStream.getReadAheadRange();
inStream.seek(newSeek);
assertGetPosition(newSeek, in.getPos());
assertDataAtPos(newSeek, (byte) in.read());
assertSeekBufferStats(1, streamStatistics.getSeekInBuffer());
remoteReadOperationsNewVal = streamStatistics.getRemoteReadOperations();
assertNoIncrementInRemoteReadOps(remoteReadOperationsOldVal,
remoteReadOperationsNewVal);
remoteReadOperationsOldVal = remoteReadOperationsNewVal;
// Seeking just after read ahead range. Read from buffer.
newSeek = inStream.getReadAheadRange() + 1;
in.seek(newSeek);
assertGetPosition(newSeek, in.getPos());
assertDataAtPos(newSeek, (byte) in.read());
assertSeekBufferStats(2, streamStatistics.getSeekInBuffer());
remoteReadOperationsNewVal = streamStatistics.getRemoteReadOperations();
assertNoIncrementInRemoteReadOps(remoteReadOperationsOldVal,
remoteReadOperationsNewVal);
remoteReadOperationsOldVal = remoteReadOperationsNewVal;
// Seeking just 10 more bytes such that data is read from buffer.
newSeek += 10;
in.seek(newSeek);
assertGetPosition(newSeek, in.getPos());
assertDataAtPos(newSeek, (byte) in.read());
assertSeekBufferStats(3, streamStatistics.getSeekInBuffer());
remoteReadOperationsNewVal = streamStatistics.getRemoteReadOperations();
assertNoIncrementInRemoteReadOps(remoteReadOperationsOldVal,
remoteReadOperationsNewVal);
remoteReadOperationsOldVal = remoteReadOperationsNewVal;
// Seek backward such that data is read from remote.
newSeek -= 106;
in.seek(newSeek);
assertGetPosition(newSeek, in.getPos());
assertDataAtPos(newSeek, (byte) in.read());
assertSeekBufferStats(3, streamStatistics.getSeekInBuffer());
remoteReadOperationsNewVal = streamStatistics.getRemoteReadOperations();
assertIncrementInRemoteReadOps(remoteReadOperationsOldVal,
remoteReadOperationsNewVal);
remoteReadOperationsOldVal = remoteReadOperationsNewVal;
// Seeking just 10 more bytes such that data is read from buffer.
newSeek += 10;
in.seek(newSeek);
assertGetPosition(newSeek, in.getPos());
assertDataAtPos(newSeek, (byte) in.read());
assertSeekBufferStats(4, streamStatistics.getSeekInBuffer());
remoteReadOperationsNewVal = streamStatistics.getRemoteReadOperations();
assertNoIncrementInRemoteReadOps(remoteReadOperationsOldVal,
remoteReadOperationsNewVal);
remoteReadOperationsOldVal = remoteReadOperationsNewVal;
// Read multiple bytes across read ahead range. Remote read.
long oldSeek = newSeek;
newSeek = 2*inStream.getReadAheadRange() -1;
byte[] bytes = new byte[5];
in.readFully(newSeek, bytes);
// With readFully getPos should return oldSeek pos.
// Adding one as one byte is already read
// after the last seek is done.
assertGetPosition(oldSeek + 1, in.getPos());
assertSeekBufferStats(4, streamStatistics.getSeekInBuffer());
assertDatasetEquals(newSeek, "Read across read ahead ",
bytes, bytes.length);
remoteReadOperationsNewVal = streamStatistics.getRemoteReadOperations();
assertIncrementInRemoteReadOps(remoteReadOperationsOldVal,
remoteReadOperationsNewVal);
}
}
/**
* Test to validate the getPos() when a seek is done
* post {@code AbfsInputStream#unbuffer} call is made.
* Also using optimised builder api to open file.
*/
@Test
public void testSeekAfterUnbuffer() throws IOException {
describe("Test to make sure that seeking in AbfsInputStream after "
+ "unbuffer() call is not doing anyIO.");
Path testFile = path(getMethodName() + ".txt");
createDataSet(testFile);
final CompletableFuture<FSDataInputStream> future =
getFileSystem().openFile(testFile)
.build();
try (FSDataInputStream inputStream = awaitFuture(future)) {
AbfsInputStream abfsInputStream = (AbfsInputStream) inputStream.getWrappedStream();
AbfsInputStreamStatisticsImpl streamStatistics =
(AbfsInputStreamStatisticsImpl) abfsInputStream.getStreamStatistics();
int readAheadRange = abfsInputStream.getReadAheadRange();
long seekPos = readAheadRange;
inputStream.seek(seekPos);
assertDataAtPos(readAheadRange, (byte) inputStream.read());
long currentRemoteReadOps = streamStatistics.getRemoteReadOperations();
assertIncrementInRemoteReadOps(0, currentRemoteReadOps);
inputStream.unbuffer();
seekPos -= 10;
inputStream.seek(seekPos);
// Seek backwards shouldn't do any IO
assertNoIncrementInRemoteReadOps(currentRemoteReadOps, streamStatistics.getRemoteReadOperations());
assertGetPosition(seekPos, inputStream.getPos());
}
}
private void createDataSet(Path path) throws IOException {
createFile(getFileSystem(), path, true, BLOCK);
}
private void assertGetPosition(long expected, long actual) {
final String seekPosErrorMsg = "getPos() should return %s";
Assertions.assertThat(actual)
.describedAs(seekPosErrorMsg, expected)
.isEqualTo(actual);
}
private void assertDataAtPos(int pos, byte actualData) {
final String dataErrorMsg = "Mismatch in data@%s";
Assertions.assertThat(actualData)
.describedAs(dataErrorMsg, pos)
.isEqualTo(BLOCK[pos]);
}
private void assertSeekBufferStats(long expected, long actual) {
final String statsErrorMsg = "Mismatch in seekInBuffer counts";
Assertions.assertThat(actual)
.describedAs(statsErrorMsg)
.isEqualTo(expected);
}
private void assertNoIncrementInRemoteReadOps(long oldVal, long newVal) {
final String incrementErrorMsg = "Number of remote read ops shouldn't increase";
Assertions.assertThat(newVal)
.describedAs(incrementErrorMsg)
.isEqualTo(oldVal);
}
private void assertIncrementInRemoteReadOps(long oldVal, long newVal) {
final String incrementErrorMsg = "Number of remote read ops should increase";
Assertions.assertThat(newVal)
.describedAs(incrementErrorMsg)
.isGreaterThan(oldVal);
}
/**
* Assert that the data read matches the dataset at the given offset.
* This helps verify that the seek process is moving the read pointer
* to the correct location in the file.
* @param readOffset the offset in the file where the read began.
* @param operation operation name for the assertion.
* @param data data read in.
* @param length length of data to check.
*/
private void assertDatasetEquals(
final int readOffset,
final String operation,
final byte[] data,
int length) {
for (int i = 0; i < length; i++) {
int o = readOffset + i;
Assertions.assertThat(data[i])
.describedAs(operation + "with read offset " + readOffset
+ ": data[" + i + "] != actualData[" + o + "]")
.isEqualTo(BLOCK[o]);
}
}
}

4
hadoop-tools/hadoop-azure/src/test/java/org/apache/hadoop/fs/azurebfs/services/ITestAbfsInputStream.java
View File

@ -247,8 +247,8 @@ private void verifyBeforeSeek(AbfsInputStream abfsInputStream){
assertEquals(0, abfsInputStream.getBCursor());
}
private void verifyAfterSeek(AbfsInputStream abfsInputStream, long seekPos){
assertEquals(seekPos, abfsInputStream.getFCursor());
private void verifyAfterSeek(AbfsInputStream abfsInputStream, long seekPos) throws IOException {
assertEquals(seekPos, abfsInputStream.getPos());
assertEquals(-1, abfsInputStream.getFCursorAfterLastRead());
assertEquals(0, abfsInputStream.getLimit());
assertEquals(0, abfsInputStream.getBCursor());