RFR: 8271232: JFR: Scrub recording data [v3]

[Erik Gahlin]

On Wed, 23 Feb 2022 08:47:14 GMT, Gunnar Morling <duke at openjdk.java.net> wrote:

>> Yes, I also considered thresholds and random removal of events, but got lost in how the option syntax should look like. There is some precedence in JFR.dump that we might want to use, or not. In the end, I decided to keep the command line tool simple for now, all the filtering capabilities exists in the API. Most likely, I will revisit the tool later in the release to fix a few things. If time permits, I might look at time-based filtering as well then.
>
> That makes sense. Would you be open for a contribution by someone else (i.e. me) for the time-based filtering, once this initial work has been merged?

Changes to command line options require a CSR request and updating the documentation. I might as well do it when I fix other related issues, but it would be interesting to better understand the use case.

JFR.dump have four options, "begin", "end", "maxsize" and "maxage". Option "begin" and "end" accepts a timestamp but it can also be relative time, for example "begin=-30m", to dump the last 30 minutes, or you can do "maxage=30m".  It's possible to do combinations. For example, begin ="2022-02-23T12:49:54.913875Z" maxsize=100M to have a 100 MB before a particular timestamp. 

Not sure if that is what we want?

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PR: https://git.openjdk.java.net/jdk/pull/7548