[ 
https://issues.apache.org/jira/browse/HBASE-862?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12659849#action_12659849
 ] 

Andrew Purtell commented on HBASE-862:
--------------------------------------

+1

Seeing this on our cluster as well. Master starts up in safe mode. All HRS 
start up and check in. Then initial assignments start. Assignment is lumpy -- 
average load should be e.g. 40, some HRS get e.g. 80 initial assignments. They 
report as overloaded, so then regions are closed and moved almost as soon as 
they are opened. Compaction/split load is increased unnecessarily. 

Also seeing asserts about illegal state transitions from the Master.

All regions do come up assigned and HRS are evenly loaded after a while, unless 
compaction/split load overwhelms DFS. Then usually there are a few regions that 
did not deploy correctly that have to be manually (re)deployed with 
close_region from the shell. 


> region balancing is clumsy
> --------------------------
>
>                 Key: HBASE-862
>                 URL: https://issues.apache.org/jira/browse/HBASE-862
>             Project: Hadoop HBase
>          Issue Type: Bug
>            Reporter: stack
>
> Daniel Leffel has an install of 500 regions on 4 nodes.  He's running 0.2.0.
> On restart, load balancing is running while the 600 regions are being 
> initially opened.  Makes for churn.  Load balancing should wait before it 
> cuts in.
> Have also seen on occasion that it will not find equilibrium after a restart.
> Adding a node is catastrophic.  >20% of the regions were closed and were 
> taking the longest time to show up on the new server.  I would think that the 
> region balancing would work in more sophisticated and gradual manner.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to