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Eric Payne commented on HDFS-3828: ---------------------------------- Since this patch has already been merged to trunk and branch 2, is this patch still needed in 0.23? If not, can we close this issue? > Block Scanner rescans blocks too frequently > ------------------------------------------- > > Key: HDFS-3828 > URL: https://issues.apache.org/jira/browse/HDFS-3828 > Project: Hadoop HDFS > Issue Type: Bug > Affects Versions: 0.23.0 > Reporter: Andy Isaacson > Assignee: Andy Isaacson > Fix For: 2.5.0 > > Attachments: hdfs-3828-1.txt, hdfs-3828-2.txt, hdfs-3828-3.txt, > hdfs3828.txt > > > {{BlockPoolSliceScanner#scan}} calls cleanUp every time it's invoked from > {{DataBlockScanner#run}} via {{scanBlockPoolSlice}}. But cleanUp > unconditionally roll()s the verificationLogs, so after two iterations we have > lost the first iteration of block verification times. As a result a cluster > with just one block repeatedly rescans it every 10 seconds: > {noformat} > 2012-08-16 15:59:57,884 INFO datanode.BlockPoolSliceScanner > (BlockPoolSliceScanner.java:verifyBlock(391)) - Verification succeeded for > BP-2101131164-172.29.122.91-1337906886255:blk_7919273167187535506_4915 > 2012-08-16 16:00:07,904 INFO datanode.BlockPoolSliceScanner > (BlockPoolSliceScanner.java:verifyBlock(391)) - Verification succeeded for > BP-2101131164-172.29.122.91-1337906886255:blk_7919273167187535506_4915 > 2012-08-16 16:00:17,925 INFO datanode.BlockPoolSliceScanner > (BlockPoolSliceScanner.java:verifyBlock(391)) - Verification succeeded for > BP-2101131164-172.29.122.91-1337906886255:blk_7919273167187535506_4915 > {noformat} > {quote} > To fix this, we need to avoid roll()ing the logs multiple times per period. -- This message was sent by Atlassian JIRA (v6.2#6252)