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Eric Newton commented on ACCUMULO-1770: --------------------------------------- The one fact that bothers me is the use of swap without a negative impact on performance. It seems to me that the memory isn't being used/reused, which is troubling. Also, there's not a lot of tools to help understand the usage patterns. > 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)