Mnimum Probe Overhead

Questions about YourKit Java Profiler
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aedwards
Posts: 6
Joined: Mon Mar 14, 2016 5:33 pm

Mnimum Probe Overhead

Post by aedwards »

Hi there,

I am using the agent headless and specifying the settings on the command line. I would like to configure a bunch of runs that capture different information but ideally are as low impact as possible. The profiler is profiling an application running in tomcat.

I can disable most things for cpu profiling using these settings =disableall,delay=30000,sampling

Is there a way I can capture database (& later sevlet) probe info with minimum instrumentation overhead? The only settings I have so far are =disablealloc,disableexceptiontelemetry,disablestacktelemetry,probe_disable=*,probe_on=com.yourkit.probes.builtin.Databases,delay=30000,tracing but this batters the CPU right from the get go.

In addition is allocsampled the same idea as cpu sampling vs instrumentation?
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Re: Mnimum Probe Overhead

Post by Anton Katilin »

Which version of the profiler do you use?

Please try the following (it's your line with sampling instead of tracing):

=disablealloc,disableexceptiontelemetry,disablestacktelemetry,probe_disable=*,probe_on=.Databases,delay=30000,sampling
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Re: Mnimum Probe Overhead

Post by Anton Katilin »

> In addition is allocsampled the same idea as cpu sampling vs instrumentation?
Almost.
The difference is how the stack traces are obtained, explicitly for each allocated object or approximately by using a sampling approach.
aedwards
Posts: 6
Joined: Mon Mar 14, 2016 5:33 pm

Re: Mnimum Probe Overhead

Post by aedwards »

Thanks

That did the trick. It's not clear from the docs that you can run the probes in sampling mode, the docs on the probes talk about byte code instrumentation so I assumed I had to run it with that on.
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Re: Mnimum Probe Overhead

Post by Anton Katilin »

Indeed, probes can be combined with any other profiling mode.
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