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Rahul Singhal commented on HDFS-6339: ------------------------------------- Thanks a lot for your reply [~kihwal]. I was testing both cases/paths: (non-HA, 2.2.0) -> (non-HA, 2.4.0) -> (non-HA 2.2.0) (HA, 2.2.0) -> (HA, 2.4.0) -> (non-HA, 2.2.0) -> (HA, 2.2.0) The issue with 2NN was noticed in cases 1. I guess I was mainly confused by the fact that start-dfs.sh does not fromat the 2NN during rollback. Thanks for confirming my procedure. And I will use the mailing list for future questions but since you have the context here, I was hoping you could answer one more questions. In what cases, will NN not have all edits locally? Should they be available at edits.dir? > DN, SNN & JN can't rollback data > -------------------------------- > > Key: HDFS-6339 > URL: https://issues.apache.org/jira/browse/HDFS-6339 > Project: Hadoop HDFS > Issue Type: Bug > Components: journal-node > Affects Versions: 2.2.0 > Reporter: Rahul Singhal > > I tried rollback from 2.4.0 to 2.2.0 and noticed that DN, SNN and JN couldn't > perform rollback. > I started with a (NN) HA cluster on 2.2.0 and upgraded it to 2.4.0 with HA > enabled. Then attempted a rollback to 2.2.0. I first configured my cluster to > non-HA and started it on 2.2.0. I started NN & DN with the '-rollback' > startup option. (There is no explicit startup option for SNN & JN like NN & > DN). Only NN was able to rollback correctly. > My fixes: > I fixed the DN rollback problem by cherry-picking the fix from HDFS-5526. > I fixed the SNN rollback problem by starting it with '-format' option. > I then proceeded to converting the non-HA cluster to a HA cluster. The first > step after configuration change was to start the JNs. But they also couldn't > rollback. > My fix: > I fixed this by deleting the JN data directory. (deleting the 'current' > directory and renaming 'previous' to 'current' didn't fix the rollback) > My purpose for filing this bug is to: > 1. Ask if these problems are known and intended to be fixed in any future > releases. If yes, which one? DN rollback was fixed in 2.3.0 but what about > 2.2.x series? JN rollback seems (not confirmed) to have been fixed in 2.4.0. > 2. Confirm that "my fixes" are correct. If not, please help me with an > appropriate fix. -- This message was sent by Atlassian JIRA (v6.2#6252)