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From Josh Elser <josh.el...@gmail.com>
Subject Re: default for tserver.total.mutation.queue.max increased from 50M to 1M in 1.7
Date Thu, 07 Jul 2016 17:39:32 GMT
I think there's an order-minutes property which would cause a flush on idle.

table.compaction.minor.idle IIRC

Jeff Kubina wrote:
> Interesting, is it only flushed when the buffer is full or is there a
> time limit on it also? For example, if 25M of mutations are written and
> no more when is the buffer flushed?
>
> --
> Jeff Kubina
> 410-988-4436
>
>
> On Thu, Jul 7, 2016 at 11:50 AM, Christopher <ctubbsii@apache.org
> <mailto:ctubbsii@apache.org>> wrote:
>
>     The change was introduced in
>     https://issues.apache.org/jira/browse/ACCUMULO-1950, and it's an
>     entirely new property. The old property was a per-session property.
>     The new one is per-tserver, and is a better strategy, because it
>     reduces the risk of multiple writers exhausting exhausting tserver
>     memory, while still giving the user control over how frequently
>     flushes/sync's occur.
>
>     On Thu, Jul 7, 2016 at 10:32 AM Jeff Kubina <jeff.kubina@gmail.com
>     <mailto:jeff.kubina@gmail.com>> wrote:
>
>         I noticed that the default value for
>         tserver.total.mutation.queue.max in 1.7 is 50M but in 1.6 it is
>         1M (tserver.mutation.queue.max). Is this increase to compensate
>         for the performance hit of moving the WALs to the HDFS or some
>         other factor?
>
>         Is there a way to compute the number of times the buffer is
>         flushed to calculate how this effects performance?
>
>
>         --
>         Jeff Kubina
>
>
>

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