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ramkrishna.s.vasudevan edited comment on HBASE-7391 at 8/8/13 10:44 AM: ------------------------------------------------------------------------ Patch for trunk. Once HBASE-8615 is fixed this can be checked for. Ran the test suite. Got one failure in TestWALReplay but running it once again it passed. {Edit}HBASE-8315 to HBASE-8615 {Edit} was (Author: ram_krish): Patch for trunk. Once HBASE-8315 is fixed this can be checked for. Ran the test suite. Got one failure in TestWALReplay but running it once again it passed. > Review/improve HLog compression's memory consumption > ---------------------------------------------------- > > Key: HBASE-7391 > URL: https://issues.apache.org/jira/browse/HBASE-7391 > Project: HBase > Issue Type: Bug > Reporter: Jean-Daniel Cryans > Assignee: ramkrishna.s.vasudevan > Fix For: 0.95.2 > > Attachments: HBASE-7391_1.patch > > > From Ram in > http://mail-archives.apache.org/mod_mbox/hbase-dev/201205.mbox/%3C00bc01cd31e6$7caf1320$760d3960$%25vasude...@huawei.com%3E: > {quote} > One small observation after giving +1 on the RC. > The WAL compression feature causes OOME and causes Full GC. > The problem is, if we have 1500 regions and I need to create recovered.edits > for each of the region (I don’t have much data in the regions (~300MB)). > Now when I try to build the dictionary there is a Node object getting > created. > Each node object occupies 32 bytes. > We have 5 such dictionaries. > Initially we create indexToNodes array and its size is 32767. > So now we have 32*5*32767 = ~5MB. > Now I have 1500 regions. > So 5MB*1500 = ~7GB.(Excluding actual data). This seems to a very high > initial memory foot print and this never allows me to split the logs and I > am not able to make the cluster up at all. > Our configured heap size was 8GB, tested in 3 node cluster with 5000 > regions, very less data( 1GB in hdfs cluster including replication), some > small data is spread evenly across all regions. > The formula is 32(Node object size)*5(No of dictionary)*32767(no of node > objects)*noofregions. > {quote} -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira