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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: JNA to activate cassandra row cache
Date Wed, 14 Aug 2013 19:51:38 GMT
I thought that "When installed and configured, Linux does not swap out
the JVM" was pretty straightforward.

On Wed, Aug 14, 2013 at 2:36 PM, José Elias Queiroga da Costa Araújo
<jeqca@cesar.org.br> wrote:
> Hi Michael,
>
> In my investigation about Cassandra cache, there is an implementation
> off-heap provided to RowCache,
> but this implementation is based on ByteBuffer mechanish to allocate native
> memory using JNI.
>
> However, In Datastax Cassandra documentation they say that:
> "Installing JNA can improve Cassandra memory usage.
> When installed and configured, Linux does not swap out the JVM,
> and thus avoids related performance issues."
>
> So my question is if Cassandra cache implementation is based ByteBuffer,
> there is any real reason to install JNA?
>
> Regards,
>
>
> 2013/8/14 Michael Kjellman <mkjellman@barracuda.com>
>
>> No- not required, but there is zero reason not to. Keep as much off heap
>> as possible.
>>
>> > On Aug 14, 2013, at 12:13 PM, "José Elias Queiroga da Costa Araújo" <
>> jeqca@cesar.org.br> wrote:
>> >
>> >     Hi all, I have a question.
>> >
>> >     In order to activate cassandra row cache is necessary to have JNA
>> > installed?
>> >
>> >     Regards,
>> >
>> >     *Elias.*
>>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder, http://www.datastax.com
@spyced

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