When I encountered this error it was caused by slow network which caused hdfs to be slow which caused flush to take more time thus blocking updates occurred.
Sent from my iPhone On 3 בינו 2013, at 18:25, ramkrishna vasudevan < [email protected]> wrote: You need to see your application to see how much is your rate of puts. Also how many column families do you have? All these factors will help you in determining your memstore size. Regards Ram On Thu, Jan 3, 2013 at 9:51 PM, hua beatls <[email protected]> wrote: HI, what i mean is shoud we increate the memstore according to this log? Thanks! beatls. On Thu, Jan 3, 2013 at 8:37 PM, Anoop Sam John <[email protected]> wrote: I guess you mean "what is blocking memstore size" This you can configure using 2 properties. 1. hbase.hregion.memstore.flush.size -> Using this you specify when the memstore to be flushed as a file. The default value is 128MB. So when the region memstore size reaches this value a flush will be initiated. 2. hbase.hregion.memstore.block.multiplier -> deafult value is 2 The blocking memstore size is calculated as flushSize multiplied by this multiplier. So the default value will be 256MB. What value to set depends on the total memory available for the process in the RegionServers and the total no# of regions per server. Say you set this blocking size as 512m and there can be 100 regions per region server in your cluster, then you are *possibly allowing* a total memory of 512*100 mb for the memstores alone. [RS process will not other memory also for its normal operation]. Take care of these aspects when you design -Anoop- ________________________________________ From: hua beatls [[email protected]] Sent: Thursday, January 03, 2013 5:41 PM To: [email protected] Subject: Re: reginoserver's log analysis? HI, what is the block size? how to set it ? and shoud i increate it for the memstore ? Thanks! beatls On Thu, Jan 3, 2013 at 6:23 PM, Anoop Sam John <[email protected]> wrote: 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
