w.r.t. the pipeline, please see this description: http://itm-vm.shidler.hawaii.edu/HDFS/ArchDocUseCases.html
On Mon, Apr 25, 2016 at 12:18 PM, Saad Mufti <saad.mu...@gmail.com> wrote: > Hi, > > In our large HBase cluster based on CDH 5.5 in AWS, we're constantly seeing > the following messages in the region server logs: > > 2016-04-25 14:02:55,178 INFO > org.apache.hadoop.hbase.regionserver.wal.FSHLog: Slow sync cost: 258 ms, > current pipeline: > [DatanodeInfoWithStorage[10.99.182.165:50010 > ,DS-281d4c4f-23bd-4541-bedb-946e57a0f0fd,DISK], > DatanodeInfoWithStorage[10.99.182.236:50010 > ,DS-f8e7e8c9-6fa0-446d-a6e5-122ab35b6f7c,DISK], > DatanodeInfoWithStorage[10.99.182.195:50010 > ,DS-3beae344-5a4a-4759-ad79-a61beabcc09d,DISK]] > > > These happen regularly while HBase appear to be operating normally with > decent read and write performance. We do have occasional performance > problems when regions are auto-splitting, and at first I thought this was > related but now I se it happens all the time. > > > Can someone explain what this means really and should we be concerned? I > tracked down the source code that outputs it in > > > hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/FSHLog.java > > but after going through the code I think I'd need to know much more about > the code to glean anything from it or the associated JIRA ticket > https://issues.apache.org/jira/browse/HBASE-11240. > > Also, what is this "pipeline" the ticket and code talks about? > > Thanks in advance for any information and/or clarification anyone can > provide. > > ---- > > Saad >
