[HDFS-13189] Standby NameNode should roll active edit log when checkpointing

• Type: Sub-task
• Status: Resolved
• Priority: Minor
• Resolution: Duplicate
• Component/s: namenode
• Assignee: Unassigned
• Reporter: Chao Sun
• Created: 24/Feb/18 00:36
• Updated: 02/May/19 15:48
• Resolved: 01/May/19 17:02

Description

When the SBN is doing checkpointing, it will hold the cpLock. In the current implementation of edit log tailer thread, it will first check and roll active edit log, and then tail and apply edits. In the case of checkpointing, it will be blocked on the cpLock and will not roll the edit log.

It seems there is no dependency between the edit log roll and tailing edits, so a better may be to do these in separate threads. This will be helpful for people who uses the observer feature without in-progress edit log tailing.

An alternative is to configure dfs.namenode.edit.log.autoroll.multiplier.threshold and dfs.namenode.edit.log.autoroll.check.interval.ms to let ANN roll its own log more frequently in case SBN is stuck on the lock.

Issue Links

• is duplicated by: HDFS-14349 Edit log may be rolled more frequently than necessary with multiple Standby nodes