snvijaya commented on a change in pull request #2246:
URL: https://github.com/apache/hadoop/pull/2246#discussion_r480968575
##########
File path:
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsClient.java
##########
@@ -271,10 +272,67 @@ public AbfsRestOperation deleteFilesystem() throws
AzureBlobFileSystemException
return op;
}
- public AbfsRestOperation createPath(final String path, final boolean isFile,
final boolean overwrite,
- final String permission, final String
umask,
- final boolean isAppendBlob) throws
AzureBlobFileSystemException {
+ public AbfsRestOperation createPath(final String path,
+ final boolean isFile,
+ final boolean overwrite,
+ final String permission,
+ final String umask,
+ final boolean isAppendBlob) throws AzureBlobFileSystemException {
+ String operation = isFile
+ ? SASTokenProvider.CREATE_FILE_OPERATION
+ : SASTokenProvider.CREATE_DIRECTORY_OPERATION;
+
+ // HDFS FS defaults overwrite behaviour to true for create file which leads
+ // to majority create API traffic with overwrite=true. In some cases, this
+ // will end in race conditions at backend with parallel operations issued
to
+ // same path either by means of the customer workload or ABFS driver retry.
+ // Disabling the create overwrite default setting to false should
+ // significantly reduce the chances for such race conditions.
+ boolean isFirstAttemptToCreateWithoutOverwrite = false;
+ if (isFile && overwrite
+ && abfsConfiguration.isDefaultCreateOverwriteDisabled()) {
+ isFirstAttemptToCreateWithoutOverwrite = true;
+ }
+
+ AbfsRestOperation op = null;
+ // Query builder
+ final AbfsUriQueryBuilder abfsUriQueryBuilder =
createDefaultUriQueryBuilder();
+ abfsUriQueryBuilder.addQuery(QUERY_PARAM_RESOURCE,
+ operation.equals(SASTokenProvider.CREATE_FILE_OPERATION)
+ ? FILE
+ : DIRECTORY);
+ if (isAppendBlob) {
+ abfsUriQueryBuilder.addQuery(QUERY_PARAM_BLOBTYPE, APPEND_BLOB_TYPE);
+ }
+
+ appendSASTokenToQuery(path, operation, abfsUriQueryBuilder);
+
+ try {
+ op = createPathImpl(path, abfsUriQueryBuilder,
Review comment:
Yes, this PR change is not an absolute fix to resolve the race condition
issue. But will help in reducing the overall create overwrite=true traffic with
HDFS default for overwrite being true.
##########
File path:
hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsClient.java
##########
@@ -271,10 +272,67 @@ public AbfsRestOperation deleteFilesystem() throws
AzureBlobFileSystemException
return op;
}
- public AbfsRestOperation createPath(final String path, final boolean isFile,
final boolean overwrite,
- final String permission, final String
umask,
- final boolean isAppendBlob) throws
AzureBlobFileSystemException {
+ public AbfsRestOperation createPath(final String path,
+ final boolean isFile,
+ final boolean overwrite,
+ final String permission,
+ final String umask,
+ final boolean isAppendBlob) throws AzureBlobFileSystemException {
+ String operation = isFile
+ ? SASTokenProvider.CREATE_FILE_OPERATION
+ : SASTokenProvider.CREATE_DIRECTORY_OPERATION;
+
+ // HDFS FS defaults overwrite behaviour to true for create file which leads
+ // to majority create API traffic with overwrite=true. In some cases, this
+ // will end in race conditions at backend with parallel operations issued
to
+ // same path either by means of the customer workload or ABFS driver retry.
+ // Disabling the create overwrite default setting to false should
+ // significantly reduce the chances for such race conditions.
+ boolean isFirstAttemptToCreateWithoutOverwrite = false;
+ if (isFile && overwrite
+ && abfsConfiguration.isDefaultCreateOverwriteDisabled()) {
+ isFirstAttemptToCreateWithoutOverwrite = true;
+ }
+
+ AbfsRestOperation op = null;
+ // Query builder
+ final AbfsUriQueryBuilder abfsUriQueryBuilder =
createDefaultUriQueryBuilder();
+ abfsUriQueryBuilder.addQuery(QUERY_PARAM_RESOURCE,
+ operation.equals(SASTokenProvider.CREATE_FILE_OPERATION)
+ ? FILE
+ : DIRECTORY);
+ if (isAppendBlob) {
+ abfsUriQueryBuilder.addQuery(QUERY_PARAM_BLOBTYPE, APPEND_BLOB_TYPE);
+ }
+
+ appendSASTokenToQuery(path, operation, abfsUriQueryBuilder);
+
+ try {
+ op = createPathImpl(path, abfsUriQueryBuilder,
+ (isFirstAttemptToCreateWithoutOverwrite ? false : overwrite),
+ permission, umask);
+ } catch (AbfsRestOperationException e) {
+ if ((e.getStatusCode() == HttpURLConnection.HTTP_CONFLICT)
+ && isFirstAttemptToCreateWithoutOverwrite) {
+ isFirstAttemptToCreateWithoutOverwrite = false;
+ // was a first attempt made to create without overwrite. Now try again
+ // with overwrite now.
+ op = createPathImpl(path, abfsUriQueryBuilder, true, permission,
umask);
Review comment:
Yes, this PR change is not an absolute fix to resolve the race condition
issue. But will help in reducing the overall create overwrite=true traffic with
HDFS default for overwrite being true.
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