RFR: 8196743: jstatd doesn't see new Java processes inside Docker container

[Laurence Cable]

and sadly /proc does not support inotify()!!!!



On 5/6/21 1:48 PM, Kevin Walls wrote:
> This is a merge request to fix the issue where a running jstatd does not see JVMs in docker containers started since the jstatd itself started.
>
> jstatd was using the set of temp directories gathered on startup to scan for VMs, by reading their perfdata file.  That includes existing running VMs in docker instances using tmp dirs such as /proc/PID/root/tmp/.  But it needs to re-evaluate that set of temp dirs continually to see new VMs in docker containers.  Rescanning also means it "forgets" about tmp dirs which have disappeared, for containers that have shutdown, and it will now not be scanning those directories forever.
>
> Have been testing this manually, watching jps connecting to jstatd and show newly created JVMs in docker containers come and go.  Running existing tests OK so far.
>
> -------------
>
> Commit messages:
>   - 8196743: jstatd doesn't see new Java processes inside Docker container
>
> Changes: https://git.openjdk.java.net/jdk/pull/3908/files
>   Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=3908&range=00
>    Issue: https://bugs.openjdk.java.net/browse/JDK-8196743
>    Stats: 10 lines in 1 file changed: 5 ins; 3 del; 2 mod
>    Patch: https://git.openjdk.java.net/jdk/pull/3908.diff
>    Fetch: git fetch https://git.openjdk.java.net/jdk pull/3908/head:pull/3908
>
> PR: https://git.openjdk.java.net/jdk/pull/3908

-------------- next part --------------
A non-text attachment was scrubbed...
Name: larry_cable.vcf
Type: text/x-vcard
Size: 217 bytes
Desc: not available
URL: <https://mail.openjdk.java.net/pipermail/serviceability-dev/attachments/20210506/2d0958e2/larry_cable.vcf>