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From "CROCKETT, LEONARD P" <lc1...@att.com>
Subject RE: JNA to activate cassandra row cache
Date Mon, 19 Aug 2013 18:49:38 GMT
Hello dev community,

Must Cassandra 1.2.5 run as root for JNA jar to effectively disable swapping?

Also is platform jar required?

Thanks,
Leonard Crockett
Leonard.crockett@att.com


-----Original Message-----
From: Michael Kjellman [mailto:mkjellman@barracuda.com] 
Sent: Wednesday, August 14, 2013 12:40 PM
To: dev@cassandra.apache.org
Subject: Re: JNA to activate cassandra row cache

Well- as I said there isn't a reason not to. Licensing issues have even recently been worked
out but I forgot about the sun.misc.unsafe work in 1.1+ so thanks Jonathan for correcting
me. 

> On Aug 14, 2013, at 12:36 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.*
>> 
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