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HDDS-2870. Adding OMReplayException to handle replay case
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@hanishakoneru
hanishakoneru committed Jan 28, 2020
1 parent f1a8ac0 commit e573284
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38 changes: 38 additions & 0 deletions ...p-ozone/common/src/main/java/org/apache/hadoop/ozone/om/exceptions/OMReplayException.java
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@@ -0,0 +1,38 @@
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.ozone.om.exceptions;

import java.io.IOException;

/**
* Exception thrown by Ozone Manager when a transaction is replayed. This
* exception should not be thrown to client. It is used in
* OMClientRequest#validateAndUpdateCache to log error and continue in case
* of replay transaction.
*/
public class OMReplayException extends IOException {

public OMReplayException() {
// Dummy message. This exception is not thrown to client.
super("Replayed transaction");
}

public OMReplayException(String message) {
super(message);
}
}
216 changes: 114 additions & 102 deletions ...ne-manager/src/main/java/org/apache/hadoop/ozone/om/request/file/OMFileCreateRequest.java
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Expand Up @@ -30,6 +30,7 @@

import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import org.apache.hadoop.ozone.om.exceptions.OMReplayException;
import org.apache.hadoop.ozone.om.response.file.OMFileCreateResponse;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
Expand Down Expand Up @@ -218,117 +219,126 @@ public OMClientResponse validateAndUpdateCache(OzoneManager ozoneManager,
OmKeyInfo dbKeyInfo = omMetadataManager.getKeyTable().get(ozoneKey);
if (dbKeyInfo != null) {
// Check if this transaction is a replay of ratis logs.
// Check if this transaction is a replay of ratis logs.
// We check only the KeyTable here and not the OpenKeyTable. In case
// this transaction is a replay but the transaction was not committed
// to the KeyTable, then we recreate the key in OpenKey table. This is
// okay as all the subsequent transactions would also be replayed and
// the openKey table would eventually reach the same state.
// The reason we do not check the OpenKey table is to avoid a DB read
// in regular non-replay scenario.
if (isReplay(ozoneManager, dbKeyInfo.getUpdateID(), trxnLogIndex)) {
// Replay implies the response has already been returned to
// the client. So take no further action and return a dummy response.
result = Result.REPLAY;
omClientResponse = new OMFileCreateResponse(createReplayOMResponse(
omResponse));
throw new OMReplayException();
}
}

if (result == null) {

OMFileRequest.OMDirectoryResult omDirectoryResult =
OMFileRequest.verifyFilesInPath(omMetadataManager, volumeName,
bucketName, keyName, Paths.get(keyName));
OMFileRequest.OMDirectoryResult omDirectoryResult =
OMFileRequest.verifyFilesInPath(omMetadataManager, volumeName,
bucketName, keyName, Paths.get(keyName));

// Check if a file or directory exists with same key name.
if (omDirectoryResult == FILE_EXISTS) {
if (!isOverWrite) {
throw new OMException("File " + keyName + " already exists",
OMException.ResultCodes.FILE_ALREADY_EXISTS);
}
} else if (omDirectoryResult == DIRECTORY_EXISTS) {
throw new OMException("Can not write to directory: " + keyName,
OMException.ResultCodes.NOT_A_FILE);
} else if (omDirectoryResult == FILE_EXISTS_IN_GIVENPATH) {
throw new OMException(
"Can not create file: " + keyName + " as there " +
"is already file in the given path",
OMException.ResultCodes.NOT_A_FILE);
// Check if a file or directory exists with same key name.
if (omDirectoryResult == FILE_EXISTS) {
if (!isOverWrite) {
throw new OMException("File " + keyName + " already exists",
OMException.ResultCodes.FILE_ALREADY_EXISTS);
}
} else if (omDirectoryResult == DIRECTORY_EXISTS) {
throw new OMException("Can not write to directory: " + keyName,
OMException.ResultCodes.NOT_A_FILE);
} else if (omDirectoryResult == FILE_EXISTS_IN_GIVENPATH) {
throw new OMException(
"Can not create file: " + keyName + " as there " +
"is already file in the given path",
OMException.ResultCodes.NOT_A_FILE);
}

if (!isRecursive) {
// We cannot create a file if complete parent directories don't exist.

// verifyFilesInPath, checks only the path and its parent directories.
// But there may be some keys below the given path. So this method
// checks them.

// Example:
// Existing keys in table
// a/b/c/d/e
// a/b/c/d/f
// a/b

// Take an example if given key to be created with isRecursive set
// to false is "a/b/c/e".
// There is no key in keyTable with the provided path.
// Check in case if there are keys exist in given path. (This can
// happen if keys are directly created using key requests.)

// We need to do this check only in the case of non-recursive, so
// not included the checks done in checkKeysUnderPath in
// verifyFilesInPath method, as that method is common method for
// directory and file create request. This also avoid's this
// unnecessary check which is not required for those cases.
if (omDirectoryResult == NONE ||
omDirectoryResult == DIRECTORY_EXISTS_IN_GIVENPATH) {
boolean canBeCreated = checkKeysUnderPath(omMetadataManager,
volumeName, bucketName, keyName);
if (!canBeCreated) {
throw new OMException("Can not create file: " + keyName +
" as one of parent directory is not created",
OMException.ResultCodes.NOT_A_FILE);
}
if (!isRecursive) {
// We cannot create a file if complete parent directories don't exist.

// verifyFilesInPath, checks only the path and its parent directories.
// But there may be some keys below the given path. So this method
// checks them.

// Example:
// Existing keys in table
// a/b/c/d/e
// a/b/c/d/f
// a/b

// Take an example if given key to be created with isRecursive set
// to false is "a/b/c/e".
// There is no key in keyTable with the provided path.
// Check in case if there are keys exist in given path. (This can
// happen if keys are directly created using key requests.)

// We need to do this check only in the case of non-recursive, so
// not included the checks done in checkKeysUnderPath in
// verifyFilesInPath method, as that method is common method for
// directory and file create request. This also avoid's this
// unnecessary check which is not required for those cases.
if (omDirectoryResult == NONE ||
omDirectoryResult == DIRECTORY_EXISTS_IN_GIVENPATH) {
boolean canBeCreated = checkKeysUnderPath(omMetadataManager,
volumeName, bucketName, keyName);
if (!canBeCreated) {
throw new OMException("Can not create file: " + keyName +
" as one of parent directory is not created",
OMException.ResultCodes.NOT_A_FILE);
}
}

// do open key
OmBucketInfo bucketInfo = omMetadataManager.getBucketTable().get(
omMetadataManager.getBucketKey(volumeName, bucketName));
encryptionInfo = getFileEncryptionInfo(ozoneManager, bucketInfo);

omKeyInfo = prepareKeyInfo(omMetadataManager, keyArgs, dbKeyInfo,
keyArgs.getDataSize(), locations, encryptionInfo.orNull(),
ozoneManager.getPrefixManager(), bucketInfo, trxnLogIndex);

long openVersion = omKeyInfo.getLatestVersionLocations().getVersion();
long clientID = createFileRequest.getClientID();
String dbOpenKeyName = omMetadataManager.getOpenKey(volumeName,
bucketName, keyName, clientID);

// Append new blocks
omKeyInfo.appendNewBlocks(keyArgs.getKeyLocationsList().stream()
.map(OmKeyLocationInfo::getFromProtobuf)
.collect(Collectors.toList()), false);

// Add to cache entry can be done outside of lock for this openKey.
// Even if bucket gets deleted, when commitKey we shall identify if
// bucket gets deleted.
omMetadataManager.getOpenKeyTable().addCacheEntry(
new CacheKey<>(dbOpenKeyName),
new CacheValue<>(Optional.of(omKeyInfo), trxnLogIndex));

// Prepare response
omResponse.setCreateFileResponse(CreateFileResponse.newBuilder()
.setKeyInfo(omKeyInfo.getProtobuf())
.setID(clientID)
.setOpenVersion(openVersion).build())
.setCmdType(Type.CreateFile);
omClientResponse = new OMFileCreateResponse(omResponse.build(),
omKeyInfo, clientID);

result = Result.SUCCESS;
}

// do open key
OmBucketInfo bucketInfo = omMetadataManager.getBucketTable().get(
omMetadataManager.getBucketKey(volumeName, bucketName));
encryptionInfo = getFileEncryptionInfo(ozoneManager, bucketInfo);

omKeyInfo = prepareKeyInfo(omMetadataManager, keyArgs, dbKeyInfo,
keyArgs.getDataSize(), locations, encryptionInfo.orNull(),
ozoneManager.getPrefixManager(), bucketInfo, trxnLogIndex);

long openVersion = omKeyInfo.getLatestVersionLocations().getVersion();
long clientID = createFileRequest.getClientID();
String dbOpenKeyName = omMetadataManager.getOpenKey(volumeName,
bucketName, keyName, clientID);

// Append new blocks
omKeyInfo.appendNewBlocks(keyArgs.getKeyLocationsList().stream()
.map(OmKeyLocationInfo::getFromProtobuf)
.collect(Collectors.toList()), false);

// Add to cache entry can be done outside of lock for this openKey.
// Even if bucket gets deleted, when commitKey we shall identify if
// bucket gets deleted.
omMetadataManager.getOpenKeyTable().addCacheEntry(
new CacheKey<>(dbOpenKeyName),
new CacheValue<>(Optional.of(omKeyInfo), trxnLogIndex));

// Prepare response
omResponse.setCreateFileResponse(CreateFileResponse.newBuilder()
.setKeyInfo(omKeyInfo.getProtobuf())
.setID(clientID)
.setOpenVersion(openVersion).build())
.setCmdType(Type.CreateFile);
omClientResponse = new OMFileCreateResponse(omResponse.build(),
omKeyInfo, clientID);

result = Result.SUCCESS;
} catch (IOException ex) {
result = Result.FAILURE;
exception = ex;
omMetrics.incNumCreateFileFails();
omResponse.setCmdType(Type.CreateFile);
omClientResponse = new OMFileCreateResponse(createErrorOMResponse(
omResponse, exception));
if (ex instanceof OMReplayException) {
result = Result.REPLAY;
omClientResponse = new OMFileCreateResponse(createReplayOMResponse(
omResponse));
} else {
result = Result.FAILURE;
exception = ex;
omMetrics.incNumCreateFileFails();
omResponse.setCmdType(Type.CreateFile);
omClientResponse = new OMFileCreateResponse(createErrorOMResponse(
omResponse, exception));
}
} finally {
if (omClientResponse != null) {
omClientResponse.setFlushFuture(omDoubleBufferHelper.add(
Expand All @@ -341,10 +351,12 @@ public OMClientResponse validateAndUpdateCache(OzoneManager ozoneManager,
}

// Audit Log outside the lock
Map<String, String> auditMap = buildKeyArgsAuditMap(keyArgs);
auditLog(ozoneManager.getAuditLogger(), buildAuditMessage(
OMAction.CREATE_FILE, auditMap, exception,
getOmRequest().getUserInfo()));
if (result != Result.REPLAY) {
Map<String, String> auditMap = buildKeyArgsAuditMap(keyArgs);
auditLog(ozoneManager.getAuditLogger(), buildAuditMessage(
OMAction.CREATE_FILE, auditMap, exception,
getOmRequest().getUserInfo()));
}

switch (result) {
case REPLAY:
Expand Down

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