Known Issues in Apache HBase
Learn about the known issues in HDFS, 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
- Workaround: Stop HBase using Cloudera Manager before deleting an Operational Database Data Hub cluster.
IntegrationTestReplicationfails if replication does not finish before theverifyphase begins-
During
IntegrationTestReplication, if theverifyphase starts before thereplicationphase finishes, the test fails 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. - 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 postOperationproblems 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. - If
hbaseAdmin.modifyTable()is used to delete column families, the rights are not removed from the Access Control List (ACL) table. TheportOperationis implemented only forpostDeleteColumn(). - If
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. - CDPD-77399: HBase fails to register the servlet metrics and throws ClassNotFoundException: org.apache.hadoop.metrics.MetricsServlet
- The MetricsServlet class is a Hadoop 2-based metric servlet unavailable in Hadoop 3 deployments.
