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Josh Elser commented on ACCUMULO-1770: -------------------------------------- bq. The one fact that bothers me is the use of swap without a negative impact on performance Hypothetically, I could see that. For example, what if you have a bunch of jars in lib or lib/ext that you use very infrequently. These could be swapped to disk and you likely wouldn't pay any penalty because you aren't using them. Of course, that's just a guess and isn't founded at all (which goes back to your 'lack of tools to help' comment). > out of memory error on very long running tablet server > ------------------------------------------------------ > > Key: ACCUMULO-1770 > URL: https://issues.apache.org/jira/browse/ACCUMULO-1770 > Project: Accumulo > Issue Type: Bug > Components: tserver > Reporter: Eric Newton > Assignee: Eric Newton > Attachments: FragmentTest.java, memory-usage.png > > > On a large cluster it was noticed that a few of the tablet servers had been > pushed into swap. This didn't effect the performance of the server until it > ran out of memory, and the process was killed. The gc reports in the debug > log showed the system had plenty of heap space for the JVM. The number of > threads in the server were not excessive (dozens). This cluster ingests some > large values (megabytes). The tablet server had been up for a month prior to > running out of memory. MALLOC_ARENA_MAX had already been set to 1. > * Investigate the effect of fragmentation on memory usage for large value > inserts. -- This message was sent by Atlassian JIRA (v6.1#6144)