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From Claus Ibsen <>
Subject Re: How to ensure LevelDB store uses a JNI driver
Date Wed, 06 Mar 2013 07:35:27 GMT
On Wed, Mar 6, 2013 at 8:00 AM, SuoNayi <> wrote:
> Also I saw the leveldb-0.2.jar in the extra directory under the lib directory, seems
it's the java LevelDB implement.
> I removed the jar from the extra directory and deployed a new broker on other new CentOS
server and restarted the broker,
> but I could still send messages to the new broker and log files created by LevelDB were
present in the specific directory.

I think the leveldb driver/transport has a Java based driver that it
fallback and use if the JNI is not possible/present.

Though Hiram would be the best person to answer that.

And yeah if there is something we can make more obvious from INFO
logging when starting the broker which one is in use, that would be

> So here I'm more confused about that the broker with removal the leveldb-0.2.jar is deployed
on the new CentOS server without
> LevelDB installation can still work.
> The version is activemq-5.7.0.fuse-71-047.
> At 2013-03-06 13:36:46,SuoNayi <> wrote:
>>Hi ,
>>Can we ensure LevelDB store uses a JNI driver or not via logging?
>>I have deployed brokers on two CentOS servers, one server with LevelDB installation
while the other without installation.
>>After changing the logging level to DEBUG, I still can not find logs to indicate that
a JNI driver or a pure java implement is used.
>>On the same server my broker was deployed without LevelDB installation at first, I
use a simple load producer to send massive
>>messages to measure performance,after that I installed LevelDB and restarted the broker
and the load producer.
>>What make me confused is that the performance measure is very close. So I suspect
if the JNI driver is used or not.
>>If not used the java LevelDB will be used?Can I assume the JNI driver always performs
better than the java driver?

Claus Ibsen
Red Hat, Inc.
FuseSource is now part of Red Hat
Twitter: davsclaus
Author of Camel in Action:

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