The writes to your table will be written 1st to in memory data structure (memstore). When this memstore reaches some defined size it will be flushed into the file system and the memory can be cleared.
The flush operation may take some time as IO write is involved, During this time also the client may be writing data to the table. Well HBase allows to do so and the data there in memory for a region can be becoming more and more. So there will be a max amount of total data which can be there in memory. If that is crossed HBase will stop taking any writes from the client until the flush is over and the memory got cleared. As per the log in your cluster the blocking memstore size is 256m. Hope you got the idea. -Anoop- ________________________________________ From: hua beatls [[email protected]] Sent: Thursday, January 03, 2013 3:15 PM To: [email protected] Subject: reginoserver's log analysis? Hi, below is the regionserver's log, what does the red marked "blocking updates" mean ? any indication from " memstore size 256.8m is >= than blocking 256.0m size" 42,651 INFO org.apache.hadoop.hbase.regionserver.HRegion: Blocking updatesfor 'IPC Server handler 1 on 60020' on region BT_NET_LOG_999,0000189020000000000000000000000000000000,1357201912899.efd6fd4581483aded26175300c48b7b7.: memstore size 256.8m is >= than blocking 256.0m size 2013-01-03 17:00:42,717 INFO org.apache.hadoop.hbase.regionserver.HRegion: Blocking updates for 'IPC Server handler 27 on 60020' on region BT_NET_LOG_999,0000189020000000000000000000000000000000,1357201912899.efd6fd4581483aded26175300c48b7b7.: memstore size 256.8m is >= than blocking 256.0m size 2013-01-03 17:00:42,761 INFO org.apache.hadoop.hbase.regionserver.HRegion: Blocking updates for 'IPC Server handler 50 on 60020' on region BT_NET_LOG_999,0000189020000000000000000000000000000000,1357201912899.efd6fd4581483aded26175300c48b7b7.: memstore size 256.8m is >= than blocking 256.0m size 2013-01-03 17:00:42,875 INFO org.apache.hadoop.hbase.regionserver.HRegion: Blocking updates for 'IPC Server handler 55 on 60020' on region BT_NET_LOG_999,0000189020000000000000000000000000000000,1357201912899.efd6fd4581483aded26175300c48b7b7.: memstore size 256.8m is >= than blocking 256.0m size Thanks! beatls
