[jira] [Assigned] (KUDU-2356) Idle WALs can consume significant memory

["Todd Lipcon (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/KUDU-2356?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Todd Lipcon reassigned KUDU-2356:
---------------------------------

    Assignee:     (was: Todd Lipcon)

> Idle WALs can consume significant memory
> ----------------------------------------
>
>                 Key: KUDU-2356
>                 URL: https://issues.apache.org/jira/browse/KUDU-2356
>             Project: Kudu
>          Issue Type: Improvement
>          Components: log, tserver
>    Affects Versions: 1.7.0
>            Reporter: Todd Lipcon
>            Priority: Major
>         Attachments: heap.svg
>
>
> I grabbed a heap sample of a tserver which has been running a write workload for a little while and found that 750MB of memory is used by faststring allocations inside WritableLogSegment::WriteEntryBatch. It seems like this is the 'compress_buf_' member. This buffer always resizes up during a log write but never shrinks back down, even when the WAL is idle. We should consider clearing the buffer after each append, or perhaps after a short timeout like 100ms after a WAL becomes idle.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)