Question about probe data retention and control

Questions about YourKit Java Profiler
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EstherLeonard
Posts: 2
Joined: Sun Sep 20, 2015 10:47 am

Question about probe data retention and control

Post by EstherLeonard »

Hi,

I have a few questions about the probe data retention and control.

1. Can the probe data be retained on the same schedule as the telemetry data (controlled by telemetrylimit=<hours>) ?

For some types of probes, e.g. JDBC, Socket, Thread, I would the probe data to show only the activity that occurred in the visible time range shown in the Thread View. As stacktrace/telemetry data is pruned from the ThreadView, the probe data for those time periods should also be pruned.

The current behavior works fine when I am profiling the startup of the application or the 1st hour, but when I am looking at the behavior in the 24th hour after startup, the probe data either has already reached retention limit (yjp.probe.table.length.limit), or if it still recording in the current hour, in can be hard to analyze because the ThreadView only has the current hour but the probe data has 24 hours.

Because all probe data is retained, I am having to set yjp.probe.table.length.limit to some extreme values e.g. 5,000,000 to try to capture the behavior in the 24th hours. Also, to stretch the probe data capacity, I turn off all probes I'm not interested in. For example, if I am looking into database related issue, I will set it startup options builtinprobes=none,probe=com.yourkit.probes.builtin.Databases.

The main way I look at the probe data is using the Call Tree on the Probes tab. The Call Tree is much harder to look at when it contains everything since startup, but you are only looking at the current hour.

2. Can we turn collection of probe data on and off, similar to what we can do for cpu sampling and object allocation?

3. Can we clear probe data?

Thanks,
Anton Katilin
Posts: 6172
Joined: Wed Aug 11, 2004 8:37 am

Re: Question about probe data retention and control

Post by Anton Katilin »

Hi,

1. No. Individual events have the limit, as you mentioned.
2. Yes. Please see the probe activity modes:
https://www.yourkit.com/docs/java/help/ ... probes.jsp
3. Yes, both from the UI ("Clear" button in the Events tab) or by using the profiler API (class Controller method clearEventTables(String... tableNames)):
https://www.yourkit.com/docs/java/help/api.jsp

Best regards,
Anton
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