Simulating a multi-processor machine

Hi there,
I am writing a server-like application and would appreciate some of the guru's advice.
During the start up and running of this app, there are quite a few operations that could block the current thread. For example one of the start-up operations opens a socket. If the socket cannot be opened then it has to wait quite a while before throwing the TimeoutException.
This gives the application a slow feeling to it. (Not that any of GUI thread stuff is blocking, just the data comes through slowly).
Now I do know about Threading, and I can go that route quite easily, however I am not keen on the thread creation overhead (+-20k memory for each thread, even though most of the tasks are incredibly short lived)
What I am interested in is a hybrid approach. I was thinking of simulating a multi-processor machine. This would entail have a fixed number of Threads, and sending them work as the tasks arrive.
However to coordinate these threads, will require a fair amount of synchronized code, so I am not sure if it worth it.
Has anyone tried such an approach, or have any ideas about this?
Many thanks
-Philip.

Sorry about the double post,
please ignore this thread.
Wish there was a way for me to delete
this thread...
<Prays to Java Gods>

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Before anyone answers this, check out what was already attempted at his stinkin' CROSSPOST:
http://forum.java.sun.com/thread.jsp?thread=553113&forum=54&message=2706725

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I've posted this over at jGuru.com and haven't come up with an effective solution but I wanted to try here before I reported this as a bug. This deals with kicking off many threads at once (such as might happen when requests are coming in over a socket).
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My next step will likely be tearing down the application to
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mpstat in fact works on my Opteron 270 dual-processor dual-core machine running Soalris 10. For instance 'mpstat 3 5' displays 5 reports each 3 seconds apart, showing status of each CPU:
% mpstat 3 5
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl
0 1 0 1 383 245 73 0 5 0 0 87 1 0 0 99
1 1 0 1 33 4 51 0 4 0 0 57 0 0 0 99
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WLS on Multi-Processors

A few questions about WLS 5.1 on multi-processor machines:
1. Is there anything that needs to be done(other than purchase another
license) for a weblogic server to work on a multi-processor system?
2. Will WLS take advantage of all processors with just ONE invocation of WLS?
Or will I have to run one instance of WLS for each processor?
3. Will performance gains be uniform or will certain features gain more
from multiple processors?
Any answers, insights or pointers to answers are appreciated.
Thanks.
-Heng

>
I consider WebLogic to be a great no-nonsense J2EE implementation (not
counting class loaders ;-).Look for major improvements in that area in version 6.0.
Thanks,
Michael
Michael Girdley
BEA Systems Inc
"Cameron Purdy" <[email protected]> wrote in message
news:[email protected]...
Rob,
I consider WebLogic to be a great no-nonsense J2EE implementation (not
counting class loaders ;-). Gemstone's architecture is quite elaboratewhen
compared to WebLogic, and BTW they spare no opportunity to compare to
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be set up for dynamic reconfiguration of many-tier processing. Forexample,
where WL coalesces (i.e. pass by ref if possible), Gemstone will always
distribute if possible, creating a "path" through (e.g.) 7 levels of JVMs
(each level having a dynamic number of JVMs available in a pool) and if
there is a problem at any level, the request gets re-routed (full failover
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travelling salesperson problem ... you could probably implement aweb-driven
neural net on their architecture. (I've never used the Gemstone product,
but I've read about everything that they published on it.) I would assume
that for certain types of scaling problems, the Gemstone architecturewould
work very very well. I would also guess that there are latency issues and
administration nightmares, but I've had the latter with every app server
that I've ever used, so ... $.02.
Cameron Purdy
[email protected]
http://www.tangosol.com
WebLogic Consulting Available
"Rob Woollen" <[email protected]> wrote in message
news:[email protected]...
Dimitri Rakitine wrote:
Hrm. Gemstone reasons are somewhat different.I'm not a Gemstone expert, but I believe their architecture is quite
different from a WebLogic cluster. Different architectures might have
different trade-offs.
However, out of curiosity, what are their reasons?
Anyway, here is my question:
why running multiple instances of WL is more efficient than running
one
with
high execute thread count?The usual reason is that most garbage collectors suspend all of the jvm
threads. Using multiple WLS instances causes the pauses to be
staggered. Newer java vms offere incremental collectors as an option so
this may no longer as big of an issue.
-- Rob
>

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Weblogic Server: 4.5.1 SP7
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Other Questions:
1. Is there anything that needs to be done(other than purchase another
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If you are interested in modeling this before implementing it to determine
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that specializes in answering those specific performance questions, and have
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(See also eQASEsheet2.pdf) - this describes our capacity sizing tool that works
particularly well for Weblogic.
Todd
jeremy wrote:
I would like to know what performance gains I might expect from moving our
weblogic application server to a multi-processor machine. Will 2 processors
handle twice server the load of the one processor machine?
Platform: Solaris 2.6
Weblogic Server: 4.5.1 SP7
NativeIO enabled
Weblogic Server is the only thing running on the machine.
Other Questions:
1. Is there anything that needs to be done(other than purchase another
license) for the weblogic server to work on a multi-processor system?
2. Will the weblogic server naturally take advantage both processors?
3. Will performance gains be uniform or will certain features gain more
from multiple processors?
Any links or suggestions are appreciated.
thanks,
Jeremy--
Todd Wiseman
Dir/Business Development
eQASE LLC
(303)790-4242 x130
(303)790-2816
www.eqase.com
Java Performance & Scalability
[eQASE WLS Consulting Offerings.pdf]
[eQASEsheet2.pdf]

Multi-threads will run better on multi-Processores environment?

Are there any proof to say that Multi-threads will run better on multi-Processores environment?
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Thank in advance

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hey all..
how i can monitor each processor in my multi processor machine which have solaris 8 ..
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Regarding question 1: try the "mpstat" comand...
$ mpstat 3
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl
0 177 7 145 149 35 781 44 104 50 0 462 15 11 13 61
1 142 8 530 519 435 27 48 104 46 0 103 12 10 14 64
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl
0 8639 0 2906 700 589 923 72 291 222 0 7232 18 50 1 30
1 8659 0 2237 439 315 994 75 290 236 0 7370 20 52 3 25
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl
0 8350 0 2641 685 578 853 69 273 198 0 10050 23 50 2 26
1 8739 0 2353 491 313 1101 141 271 222 0 8423 21 51 1 27
CPU minf mjf xcal intr ithr csw icsw migr smtx srw syscl usr sys wt idl
0 8991 0 2834 680 554 987 81 300 238 0 6952 19 51 0 30
1 8825 0 2438 506 384 1013 80 293 237 0 7001 21 52 0 27

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Interesting to me too . .
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Here is a shot of my Machine running a 2 hour encode on Media Encoder, notice that one processor is completely maxed out while the other one is completely idle...

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          Mike Reiche <[email protected]> wrote in message
          news:3bcf1d58$[email protected]..
          >
          > You don't need two instances of WL to take advantage of two CPUs.
          >
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          >
          > Mike
          >
          >
          > "jyothi" <[email protected]> wrote:
          > >
          > >hi,
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          > >machine or do we have to install only one instance??
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          > >jyothi
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[email protected]

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Jim Ewing wrote:
>
In general, is it better to run Weblogic on a fast single processor system
or on a multi-processor system where the individual cpus are less powerful?
I am assuming that the platforms are WINTEL and all other things (memory,
disk channels etc) are equal.You'll hate me for saying this, but it depends on your application and
your client load.
I'd suggest that you run a load test against both systems and compare
the results.
>
What are the licensing implications of one philosophy over the other?You pay for WLS by the number of CPUs.
-- Rob
Coming Soon: Building J2EE Applications & BEA WebLogic Server
by Michael Girdley, Rob Woollen, and Sandra Emerson
http://learnweblogic.com

Simulating a multi-processor machine

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