Fixed Issues in Cloud Connectors

Review the list of Cloud Connectors issues that are resolved in Cloudera Runtime 7.2.10.

CDPD-18287: S3A streams are not Syncable.

The S3A output streams now raise UnsupportedOperationException on calls to Syncable.hsync() or Syncable.hflush(). This helps programs to try to use the syncable API that the stream does not save any data at all until close. Programs which use this to flush their write ahead logs will fail immediately, rather than appear to succeed but without saving any data. To downgrade the API calls to simply printing a warning, set fs.s3a.downgrade.syncable.exceptions" to true. This issue is now resolved.

CDPD-24094: Significant thread contention while initialising AzureBlobFileSystem.

Reduced the thread contention while initializing filesystems, especially AzureBlobFileSystem or other object stores. The number of filesystems that can be created in parallel is now limited in the option fs.creation.parallel.count, default value 64. A smaller value improves the worker thread startup time in processes, especially when many worker threads are attempting to interact with the same object stores. This issue is now resolved.