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Kihwal Lee commented on HDFS-7609: ---------------------------------- Compared to 0.23, edit replaying in 2.x is 5x-10x slower. This affects the namenode fail-over latency. [~mingma] also reported this issue before and saw the retry cahe being the bottleneck. > startup used too much time to load edits > ---------------------------------------- > > Key: HDFS-7609 > URL: https://issues.apache.org/jira/browse/HDFS-7609 > Project: Hadoop HDFS > Issue Type: Improvement > Components: namenode > Affects Versions: 2.2.0 > Reporter: Carrey Zhan > Attachments: HDFS-7609-CreateEditsLogWithRPCIDs.patch, > recovery_do_not_use_retrycache.patch > > > One day my namenode crashed because of two journal node timed out at the same > time under very high load, leaving behind about 100 million transactions in > edits log.(I still have no idea why they were not rolled into fsimage.) > I tryed to restart namenode, but it showed that almost 20 hours would be > needed before finish, and it was loading fsedits most of the time. I also > tryed to restart namenode in recover mode, the loading speed had no different. > I looked into the stack trace, judged that it is caused by the retry cache. > So I set dfs.namenode.enable.retrycache to false, the restart process > finished in half an hour. > I think the retry cached is useless during startup, at least during recover > process. -- This message was sent by Atlassian JIRA (v6.3.4#6332)