Thanks J-D, that's exactly what I was looking.I guess I was expecting that a manual major compaction would imply a cache flush. Should it?
-- Lars ________________________________ From: Jean-Daniel Cryans <[email protected]> To: [email protected]; lars hofhansl <[email protected]> Sent: Monday, August 15, 2011 3:59 PM Subject: Re: When are versions collected? A major compaction only compacts data in the store files (eg on disk) but not in the memstores (eg in memory). Force flush that table after you do those puts and you should get what you expect. J-D On Sun, Aug 14, 2011 at 3:33 PM, lars hofhansl <[email protected]> wrote: > Hi All, > The following is a session in hbase shell. > > You can see that VERSIONS = 1, yet even after a triggering a major compaction > I can still retrieve version 2, 3, and 4, when querying by timestamp, even > after I triggered a major compaction. > > Does "major_compact" from the shell not trigger a major compaction? > > Or does it just not do anything because there's only one small file to begin > with? > > > (HBase version is 0.90.3-cdh3u1 and it was running in local mode, in case > that makes a difference). > > > I apologize in advance if this is documented somewhere already. > > > Thanks. > > -- Lars > > > -------------- > > > hbase(main):003:0> describe 'test' > DESCRIPTION ENABLED > {NAME => 'test', FAMILIES => [{NAME => 'cf', BLOOMF true > ILTER => 'NONE', REPLICATION_SCOPE => '0', COMPRESS > ION => 'NONE', VERSIONS => '1', TTL => '2147483647' > , BLOCKSIZE => '65536', IN_MEMORY => 'false', BLOCK > CACHE => 'true'}]} > 1 row(s) in 0.0270 seconds > > hbase(main):004:0> scan 'test' > ROW COLUMN+CELL > 0 row(s) in 0.1260 seconds > > hbase(main):005:0> put 'test', 'r1', 'cf:x', 'val1' > 0 row(s) in 0.0450 seconds > > hbase(main):006:0> put 'test', 'r1', 'cf:x', 'val2' > 0 row(s) in 0.0130 seconds > > hbase(main):007:0> put 'test', 'r1', 'cf:x', 'val3' > 0 row(s) in 0.0160 seconds > > hbase(main):008:0> put 'test', 'r1', 'cf:x', 'val4' > 0 row(s) in 0.0120 seconds > > hbase(main):009:0> scan 'test' > ROW COLUMN+CELL > r1 column=cf:x, timestamp=1313360551865, value=val4 > 1 row(s) in 0.0380 seconds > > hbase(main):010:0> scan 'test', {TIMERANGE => [0, 1313360551865]} > ROW COLUMN+CELL > r1 column=cf:x, timestamp=1313360550493, value=val3 > 1 row(s) in 0.0310 seconds > > hbase(main):011:0> scan 'test', {TIMERANGE => [0, 1313360550493]} > ROW COLUMN+CELL > r1 column=cf:x, timestamp=1313360549220, value=val2 > 1 row(s) in 0.0310 seconds > > hbase(main):012:0> scan 'test', {TIMERANGE => [0, 1313360549220]} > ROW COLUMN+CELL > r1 column=cf:x, timestamp=1313360545784, value=val1 > 1 row(s) in 0.0190 seconds > > hbase(main):013:0> major_compact 'test' > 0 row(s) in 0.0670 seconds > > hbase(main):014:0> scan 'test', {TIMERANGE => [0, 1313360549220]} > ROW COLUMN+CELL > r1 column=cf:x, timestamp=1313360545784, value=val1 > 1 row(s) in 0.0230 seconds > > hbase(main):015:0> major_compact 'test' > 0 row(s) in 0.0450 seconds > > hbase(main):016:0> scan 'test', {TIMERANGE => [0, 1313360549220]} > ROW COLUMN+CELL > r1 column=cf:x, timestamp=1313360545784, value=val1 > 1 row(s) in 0.0300 seconds
