Hi all,
I am using DTrace with java 1.4
My small demo application works fine with script:
dvm$target:::method-entry
{
printf(" tid=%d, method-entry: %s:%s %s ",
tid, copyinstr(arg0), copyinstr(arg1), copyinstr(arg2));
}
dvm$target:::method-return
{
printf(" tid=%d, method-return: %s:%s %s ",
tid, copyinstr(arg0), copyinstr(arg1), copyinstr(arg2));
}
or
#!/usr/sbin/dtrace -wqs
syscall::open:entry
{
self->path = copyinstr(arg0);
}
syscall::open:return
/self->path != NULL && errno != 0 /
{
printf("open for .%s. failed with error no %d", self->path, errno);
ustack();
}
But when I connect this Dtrace scripts to Bea Weblogic App server with
our application the performance goes significantly down and there is
not possible to measure anything ...
Is it because of java 1.4? Unfortunately i am not able to use JDK5 or JDK6.
Thanks in advance.
Regards,
Zdenek Vrablik
>But when I connect this Dtrace scripts to Bea Weblogic App server with >our application the performance goes significantly down and there is >not possible to measure anything ...>Is it because of java 1.4? Unfortunately i am not able to use JDK5 or JDK6.In Java 1.4 the JVM PI is not very robust. If you load all probes it might happen exactly what you have reported. have seen the same thing with WL 8.1sp6 - Try to load only certain probes during the server initialization, see if that makes a difference ? Basically you will need to convince the Project people to run WL 8 with Java 5 or directly move your app to WebLogic 9.x which supports Java 5 and then use the new agent based on JVM TI. Im trying to finish a presentation on DTrace and Java which targets WL 9.2 and Java 5. Rgds, Stefan
Thanks Stefan, I need only use method enter and method return probe. How could I dissable all other probes? I am using only -Xrundvmpi:all and i have found parameter -XX:+DTraceMethodProbes; In DTrace User Guide is described how to enable probes, but I haven''t found how to disable probes. Thanks. Regards, Zdenek On 4/18/07, Stefan Parvu <stefanparvu14 at yahoo.com> wrote:> > >But when I connect this Dtrace scripts to Bea Weblogic App server with > >our application the performance goes significantly down and there is > >not possible to measure anything ... > > >Is it because of java 1.4? Unfortunately i am not able to use JDK5 or JDK6. > > In Java 1.4 the JVM PI is not very robust. If you load all probes it might happen > exactly what you have reported. have seen the same thing with WL 8.1sp6 - > Try to load only certain probes during the server initialization, see if > that makes a difference ? > > Basically you will need to convince the Project people to run WL 8 with Java 5 or > directly move your app to WebLogic 9.x which supports Java 5 and then use > the new agent based on JVM TI. > > Im trying to finish a presentation on DTrace and Java which targets WL 9.2 and Java 5. > > > Rgds, > Stefan > > > > >
I didn''t see it... I will use -Xrundvmpi:methods instead of all. Thanks Stefan for the advice. Regards, Zdenek On 4/19/07, Zden?k Vr?bl?k <zdenek at vrablik.org> wrote:> Thanks Stefan, > > I need only use method enter and method return probe. > How could I dissable all other probes? > > I am using only -Xrundvmpi:all and i have found > parameter -XX:+DTraceMethodProbes; > > In DTrace User Guide is described how to enable probes, but I haven''t > found how to disable probes. > > Thanks. > > Regards, > Zdenek > > On 4/18/07, Stefan Parvu <stefanparvu14 at yahoo.com> wrote: > > > > >But when I connect this Dtrace scripts to Bea Weblogic App server with > > >our application the performance goes significantly down and there is > > >not possible to measure anything ... > > > > >Is it because of java 1.4? Unfortunately i am not able to use JDK5 or JDK6. > > > > In Java 1.4 the JVM PI is not very robust. If you load all probes it might happen > > exactly what you have reported. have seen the same thing with WL 8.1sp6 - > > Try to load only certain probes during the server initialization, see if > > that makes a difference ? > > > > Basically you will need to convince the Project people to run WL 8 with Java 5 or > > directly move your app to WebLogic 9.x which supports Java 5 and then use > > the new agent based on JVM TI. > > > > Im trying to finish a presentation on DTrace and Java which targets WL 9.2 and Java 5. > > > > > > Rgds, > > Stefan > > > > > > > > > > >
Hi Stephan, preformance increased significantly, but not enough. Unfortunetuly java5 is not supported in Weblogic 8.1 server. Thank you for help. I have to find another way how check what is wrong in our application. Thanks. Regards, Zdenek Vrablik On 4/19/07, Stefan Parvu <stefanparvu14 at yahoo.com> wrote:> Hi, > > >I need only use method enter and method return probe. > >How could I dissable all other probes? > > >I am using only -Xrundvmpi:all and i have found > >parameter -XX:+DTraceMethodProbes; > > you found it. hope it helps. Be reducing the number of probes you will reduce the pressure on the jvm agent. > Once again things are not that solid and robust in Java 1.4 so the only solution is jstack or > Java 5. > Beware: Weblogic 9 does not support Java 6 so you gotta use Java 5 and the JVM TI agent. I was hoping BEA would test their core software as > well against Java 6 but it seems they didnt... > > > Cheers, > stefan > > > >