[jira] [Closed] (HBASE-2106) Cache uses only 2G of heap no matter how much allocated?

["Andrew Kyle Purtell (Jira)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/HBASE-2106?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Andrew Kyle Purtell closed HBASE-2106.
--------------------------------------

> Cache uses only 2G of heap no matter how much allocated?
> --------------------------------------------------------
>
>                 Key: HBASE-2106
>                 URL: https://issues.apache.org/jira/browse/HBASE-2106
>             Project: HBase
>          Issue Type: Bug
>            Reporter: Michael Stack
>            Priority: Major
>
> Here is a question from Adam Silberstein who is having trouble writing this list:
> "I'm running on a particular cluster of machines and seeing worse than expected performance.  I've run on a different, but identical, cluster of machines and gotten about 2-4x better throughput and latency.  I've checked all of the configuration settings and they are all the same.  The only thing I observe that looks odd is the memory usage by each region server.  I've allocated 6 GB heap space to each.  There is a total of 20GB of records on each.  When I use "top" to observe memory usage, I see that the region server process does have 6GB of virtual memory.  When I start running a workload, I can see the amount of resident memory climbing.  However, it always stops at 2GB.  Since I have 20 GB on each region server, I'd expect the process to use all the memory allocated it
> "Is there a reasonable explanation for why it stops at 2GB, and/or has anyone seen this happen"
> I took a look at the cache code and I see that it has an int for maximum size in the constructor argument though internally its using a long for maximum size.  I wonder if this is the issue?



--
This message was sent by Atlassian Jira
(v8.20.7#820007)