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From Jeff Kubina <jeff.kub...@gmail.com>
Subject Re: default for tserver.total.mutation.queue.max increased from 50M to 1M in 1.7
Date Thu, 07 Jul 2016 17:28:24 GMT
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> 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> 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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