Thanks for clarification!
At 2013-03-09 00:28:09,"Hiram Chirino" <hi...@hiramchirino.com> wrote: >On Thu, Mar 7, 2013 at 1:42 AM, SuoNayi <suonayi2...@163.com> wrote: > >> I have some confusions not answered until now: >> 1. A leveldb driver( pure java driver or the jni driver) seems like a jdbc >> driver, >> it can not save the data without talking to the store engine(database). >> For the jni driver, does it will find the installed LevelDB on the >> broker at first? >> If not found what will behave next? Just use the experimental pure >> Java LevelDB implement >> (org.iq80.leveldb.impl.*)? >> > >If the JNI driver cannot be loaded, then the pure java driver is then used. > > >> Can the pure jave driver talks to the the installed LevelDB? >> > >The pure java driver uses the same on disk format, so yes you can switch >between the two safely. > > >> I download the source code from http://code.google.com/p/leveldb/ and >> issue 'make' command >> and install LevelDB. >> > >That won't help. The the leveldb logic has been statically linked into the >jni library. That jni library is prebuilt and included in a jar. It's >extracted on demand. If you really want to build it yourself and install >it, see: >https://github.com/fusesource/leveldbjni > > >> 2. How can I only enable jni driver for the LevelDB? >> > >If on startup you don't get a warning saying your using the pure java >version, then your using the JNI driver. If you want the broker to fail to >start up if it's not using the JNI driver, then you should set the >following attribute on the levelDB element in your activemq configuration >file: indexFactory="org.fusesource.leveldbjni.JniDBFactory" > >3. Does the jni driver performs faster than the purge java driver? >> > >I have not benchmarked recently, but It was faster. > > >> 4. Is it production-ready for using LevelDB? > > >Yes. > > >> At 2013-03-06 23:36:20,"Christian Posta" <christian.po...@gmail.com> >> wrote: >> >Apollo does this. I think the logs are coming from the leveldb store, so >> >when using with ActiveMQ 5.x it should be the same (but i didn't try yet). >> >It will only log if NOT using the JNI impl. >> > >> > >> >On Wed, Mar 6, 2013 at 12:35 AM, Claus Ibsen <claus.ib...@gmail.com> >> wrote: >> > >> >> On Wed, Mar 6, 2013 at 8:00 AM, SuoNayi <suonayi2...@163.com> 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 >> >> great. >> >> >> >> >> >> > 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 <suonayi2...@163.com> 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? >> >> >> >> >> >> >> >> >>Thanks, >> >> >>SuoNayi >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >>-- >> >> >> >> >> >>Wangyin >> >> >>suonayi2...@163.com >> >> >> >> >> >> >> >> >> >> >> -- >> >> Claus Ibsen >> >> ----------------- >> >> Red Hat, Inc. >> >> FuseSource is now part of Red Hat >> >> Email: cib...@redhat.com >> >> Web: http://fusesource.com >> >> Twitter: davsclaus >> >> Blog: http://davsclaus.com >> >> Author of Camel in Action: http://www.manning.com/ibsen >> >> >> > >> > >> > >> >-- >> >*Christian Posta* >> >http://www.christianposta.com/blog >> >twitter: @christianposta >> > > > >-- > >** > >*Hiram Chirino* > >*Engineering | Red Hat, Inc.* > >*hchir...@redhat.com <hchir...@redhat.com> | fusesource.com | redhat.com* > >*skype: hiramchirino | twitter: @hiramchirino<http://twitter.com/hiramchirino> >* > >*blog: Hiram Chirino's Bit Mojo <http://hiramchirino.com/blog/>*
