Known Issues in Apache HBase
Learn about the known issues in HBase, the impact or changes to the functionality, and the workaround.
- OpDB Data Hub cluster fails to initialize if you are reusing a cloud storage location that was used by an older OpDB Data Hub cluster
- Stop HBase using Cloudera Manager before deleting an OpDB Data Hub cluster.
IntegrationTestReplicationfails if replication does not finish before the
IntegrationTestReplication, if the
verifyphase starts before the
replicationphase finishes, the test will fail because the target cluster does not contain all of the data. If the HBase services in the target cluster does not have enough memory, long garbage-collection pauses might occur.
- Use the
-tflag to set the timeout value before starting verification.
- HDFS encryption with HBase
Cloudera has tested the performance impact of using HDFS encryption with HBase. The overall overhead of HDFS encryption on HBase performance is in the range of 3 to 4% for both read and update workloads. Scan performance has not been thoroughly tested.
- AccessController postOperation problems in asynchronous operations
When security and Access Control are enabled, the following problems occur:
- If a
Delete Tablefails for a reason other than missing permissions, the access rights are removed but the table may still exist and may be used again.
hbaseAdmin.modifyTable()is used to delete column families, the rights are not removed from the Access Control List (ACL) table. The
portOperationis implemented only for
Create Tablefails, full rights for that table persist for the user who attempted to create it. If another user later succeeds in creating the table, the user who made the failed attempt still has the full rights.
- If a
- Bulk load is not supported when the source is the local HDFS
- The bulk load feature (the
completebulkloadcommand) is not supported when the source is the local HDFS and the target is an object store, such as S3/ABFS.
- Use distcp to move the HFiles from HDFS to S3 and then run bulk load from S3 to S3.
- Storing Medium Objects (MOBs) in HBase is currently not supported
- Storing MOBs in HBase relies on bulk loading files, and this is not currently supported when HBase is configured to use cloud storage (S3).
- Workaround: None