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Todd Lipcon commented on HBASE-4570: ------------------------------------ (btw, the unsafe comparator was probably just a red herring - it's faster, so the race is more likely, but pretty sure the above is the true case) > Scan ACID problem with concurrent puts. > --------------------------------------- > > Key: HBASE-4570 > URL: https://issues.apache.org/jira/browse/HBASE-4570 > Project: HBase > Issue Type: Bug > Components: client, regionserver > Affects Versions: 0.90.1, 0.90.3 > Reporter: Jonathan Hsieh > Attachments: 4570-instrumentation.tgz, hbase-4570.tgz, hbase-4570.txt > > > When scanning a table sometimes rows that have multiple column families get > split into two rows if there are concurrent writes. In this particular case > we are overwriting the contents of a Get directly back onto itself as a Put. > For example, this is a two cf row (with "f1", "f2", .. "f9" cfs). It is > actually returned as two rows (#55 and #56). Interestingly if the two were > merged we would have a single proper row. > Row row0000024461 had time stamps: [55: > keyvalues={row0000024461/f0:data/1318200440867/Put/vlen=1000, > row0000024461/f0:qual/1318200440867/Put/vlen=10, > row0000024461/f1:data/1318200440867/Put/vlen=1000, > row0000024461/f1:qual/1318200440867/Put/vlen=10, > row0000024461/f2:data/1318200440867/Put/vlen=1000, > row0000024461/f2:qual/1318200440867/Put/vlen=10, > row0000024461/f3:data/1318200440867/Put/vlen=1000, > row0000024461/f3:qual/1318200440867/Put/vlen=10, > row0000024461/f4:data/1318200440867/Put/vlen=1000, > row0000024461/f4:qual/1318200440867/Put/vlen=10}, > 56: keyvalues={row0000024461/f5:data/1318200440867/Put/vlen=1000, > row0000024461/f5:qual/1318200440867/Put/vlen=10, > row0000024461/f6:data/1318200440867/Put/vlen=1000, > row0000024461/f6:qual/1318200440867/Put/vlen=10, > row0000024461/f7:data/1318200440867/Put/vlen=1000, > row0000024461/f7:qual/1318200440867/Put/vlen=10, > row0000024461/f8:data/1318200440867/Put/vlen=1000, > row0000024461/f8:qual/1318200440867/Put/vlen=10, > row0000024461/f9:data/1318200440867/Put/vlen=1000, > row0000024461/f9:qual/1318200440867/Put/vlen=10}] > I've only tested this on 0.90.1+patches and 0.90.3+patches, but it is > consistent and duplicatable. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira