-- (RedHat Linux 6.1, with kernel modified to up the number of file
descriptors and per-user thread limits, 300MHz machine, 256MB RAM)
-- Inprise JVM 1.2.2 for Linux vs. Blackdown JVM 1.2.2 RC3
-- green threads vs. native
Preface: Tests involved hitting our Java server application, which utilizes JDBC to talk to a MySQL database on a separate box, with as many simultaneous tcp/ip connection requests as possible using Segue's Silk Performer load testing tool.
In sum:
* The Inprise Java-Linux port could not handle nearly as many simultaneous
server-side connections as the Blackdown port when using
green threads.
* Using native threads, however, the Inprise port wins hands down.
This, of course, is to be expected as the Blackdown porters have not finished
testing and fixing their native threads port yet. Using Inprise's
native threads, our application was able to handle many more simultaneous
connections than we could with the Blackdown green threads port.
It would seem that if we linux/java users could somehow combine the efforts of both camps (Sun/Inprise and Blackdown), we would have a pretty well-rounded JVM right now, since the Inprise port is doing really well with native threads, and the Blackdown guys have done a good job with green threads.
One question I have of Blackdown is why they have prioritized their green threads porting efforts over native threads, when native threads offer the best overall server-side performance (if I'm not mistaken in my assumptions)? I think more and more people are using Java for server-side development, as opposed to client-side, especially on Linux - again, if I'm not mistaken.
Thanks,
James
P.S. These ideas, informations and opinions are my own and do not necessarily express the ideas and opinions of my employer.
Mike Christiansen wrote:
James Caple wrote:
>
> For what it's worth, my experience has been that the Blackdown RC3 port is
> much more scaleable and stable than the Inprise Linux port. I'd place my
> bets on the Blackdown port for server-side performance and scaleability.
> Although somewhat slow in porting, Blackdown is doing a very thorough job.
As much as I hate to say it, my money is on Imprise. I am finding that
Blackdown's VM is causing JRun to hang. This may be a problem with
native threads, or with the fact that I am running on a two processor
SMP configuration. However, switching to Inmprise / green threads did
the trick.Mike
>
> My comments are based on tests using green threads without a JIT, at the
> moment.
>
> JC
