Regarding options of error and dump file paths

[Thomas Stüfe]

Hi Koichi,

Would it not be way less complex to just set the current working directory
to wherever you want to direct the output?

We even could give the VM a new option to let it cwd into a specific
directory after launching.

Cheers, Thomas





On Mon, Aug 23, 2021 at 5:29 AM Koichi Sakata <sakatakui at oss.nttdata.com>
wrote:

> Hi all,
>
> I'm writing to get feedback on my idea about options for error and dump
> file paths.
>
> First of all, we can specify several options related to error and dump
> files. For example, the HeapDumpPath option sets the heap dump file and
> the ErrorFile option sets the hs_error file.
>
> I've felt inconvenience about that because we need to write all path
> options to put those files in a specific directory. I also recognize
> that they are outputted in the working directory when I run an
> application with no options. But I'd like to keep them in any directory.
> So the new option that sets the directory where those files are
> outputted would be useful, I think.
>
> The new option helps us especially to run applications on containers
> like Docker, Kubernetes etc. If we run them without those existing
> options on containers, files will be put in the local directory of each
> container. We lose files after we operate the container such as deleting
> it. The option enables us to keep certainly all error and dump files if
> we just specify the path of the persistent volume for the new option.
>
> As a concrete example, when we specify -XX:ErrorAndDumpPath=/foo/bar/
> (This option name is tentative), -XX:+HeapDumpOnOutOfMemoryError and
> -XX:StartFlightRecording etc., files are generated in the /foo/bar
> directory. From my point of view, the option will deal with the
> following files:
> - heap dump file (java_pid%p.hprof)
> - error log file (hs_err_pid%p.log)
> - JFR emergency dumps (hs_err_pid%p.jfr, hs_oom_pid%p.jfr,
> hs_soe_pid%p.jfr)
> - replay file (replay_pid%p.log)
>
> The existing path options should override the new option. If I set
> -XX:ErrorAndDumpPath=/foo/bar/ and -XX:HeapDumpPath=/foo/baz/, a heap
> dump file will be in the /foo/baz directory and other files will be
> created in the /foo/bar.
>
> I would like to hear your point of view. If some people agree to this
> idea, I will write a patch.
>
> Regards,
> Koichi
>