H
henk53
A long time ago someone named kevin posted the following message. He
never got a reply, since I'm interested in these answers too I'm
reposting his message:
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I was wondering if anybody knew where I could find some good info on
the java debugger architecture, or java debugging in general. We are
doing development on weblogic 6 with the 1.3.1 jdk. On my machine,
I'll run the app server with debugging enabled, and connect from my
ide to do the actual debugging. I have a few questions...
1) Running the app server with debugging enabled (but before attaching
a client) does not seem to affect performance. Is there a performance
hit imposed by running the vm with debugging enabled?
2) Attaching the debugger slows the vm performance to a relative
crawl. Is there a way to make this a little better? A year ago we
used to run development servers with the (God forbid) Microsoft jvm
and attach with J++. The vm barely seemed to be affected by running
with a debugging client. The current sun jvm and debugging
architecture is MUCH better than it was before, but its still quite
slow.
3) After un-attaching the debug client, it seems like the vm is still
running slow. Is this correct?
4) What difference does the Hotspot server make, and does it drop
these performance enhancements when it goes into debug mode?
5) If running in JIT mode, does the compiled code get dumped when the
debugger attaches? Is this part of the bad performance (assuming the
other part is the debug info transport, and the clients evaluation of
that data)?
Any other info would be useful. Is there a good vm info place that I
can go to?
Thanks,
-Kevin
-------------
never got a reply, since I'm interested in these answers too I'm
reposting his message:
----------------
I was wondering if anybody knew where I could find some good info on
the java debugger architecture, or java debugging in general. We are
doing development on weblogic 6 with the 1.3.1 jdk. On my machine,
I'll run the app server with debugging enabled, and connect from my
ide to do the actual debugging. I have a few questions...
1) Running the app server with debugging enabled (but before attaching
a client) does not seem to affect performance. Is there a performance
hit imposed by running the vm with debugging enabled?
2) Attaching the debugger slows the vm performance to a relative
crawl. Is there a way to make this a little better? A year ago we
used to run development servers with the (God forbid) Microsoft jvm
and attach with J++. The vm barely seemed to be affected by running
with a debugging client. The current sun jvm and debugging
architecture is MUCH better than it was before, but its still quite
slow.
3) After un-attaching the debug client, it seems like the vm is still
running slow. Is this correct?
4) What difference does the Hotspot server make, and does it drop
these performance enhancements when it goes into debug mode?
5) If running in JIT mode, does the compiled code get dumped when the
debugger attaches? Is this part of the bad performance (assuming the
other part is the debug info transport, and the clients evaluation of
that data)?
Any other info would be useful. Is there a good vm info place that I
can go to?
Thanks,
-Kevin
-------------