[ http://issues.apache.org/jira/browse/HADOOP-334?page=comments#action_12447600 ] dhruba borthakur commented on HADOOP-334: -----------------------------------------
Could there be a problem if the new file by the same name 'a' gets re-created. e.g. x: add file /a/b/c, time=t0 - y: remove file /b/c, time=t1 - z: rename directory /a --> /d, time=t2 +m: create a new directory /a time=t3 Suppose the above transactions were already part of the Image. They also are in the Edits. Now, when the edits are applied, what will happen to transaction x? On a different note, isn't it safer to use sequencenumbers rather than timestamps because 1. there could be two transactions at precisely the same timestamp 2. an user can rollback the time on a machine, thus causing havoc with DFS metadata > Redesign the dfs namespace datastructures to be copy on write > ------------------------------------------------------------- > > Key: HADOOP-334 > URL: http://issues.apache.org/jira/browse/HADOOP-334 > Project: Hadoop > Issue Type: Improvement > Components: dfs > Affects Versions: 0.4.0 > Reporter: Owen O'Malley > Assigned To: Konstantin Shvachko > > The namespace datastructures should be copy on write so that the namespace > does not need to be completely locked down from user changes while the > checkpoint is being made. -- This message is automatically generated by JIRA. - If you think it was sent incorrectly contact one of the administrators: http://issues.apache.org/jira/secure/Administrators.jspa - For more information on JIRA, see: http://www.atlassian.com/software/jira
