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

[kevinjwalls]

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.

---

Progress

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Issue

• JDK-8196743: jstatd doesn't see new Java processes inside Docker container

Reviewers

• Serguei Spitsyn (@sspitsyn - Reviewer) ⚠️ Review applies to 658a9e2
• Yasumasa Suenaga (@YaSuenag - Reviewer)

Reviewing

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$ git checkout pull/3908

Update a local copy of the PR:
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$ git pr checkout 3908

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https://git.openjdk.java.net/jdk/pull/3908.diff

[bridgekeeper]

👋 Welcome back kevinw! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

@kevinjwalls The following label will be automatically applied to this pull request:

• serviceability

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[mlbridge]

Webrevs

• 01: Full - Incremental (3654447b)
• 00: Full (658a9e27)

[sspitsyn]

Hi Kevin,
This looks okay to me modulo the question from Yasumasa.
Thanks,
Serguei

[openjdk]

@kevinjwalls This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

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

Reviewed-by: sspitsyn, ysuenaga

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 15 new commits pushed to the master branch:

• ebb68d2: 8049700: Deprecate obsolete classes and methods in javax/swing/plaf/basic
• 3a474d9: 8265612: revise the help info for jmap histo command
• c97f56c: 8266172: -Wstringop-overflow happens in vmError.cpp
• 43ad24f: 8265465: jcmd VM.cds should keep already dumped archive when exception happens
• 66191ff: 8266193: BasicJMapTest does not include testHistoParallel methods
• 36e5ad6: 8263236: runtime/os/TestTracePageSizes.java fails on old kernels
• 0ca86da: 8266002: vmTestbase/nsk/jvmti/ClassPrepare/classprep001 should skip events for unexpected classes
• 52f1db6: 8262002: java/lang/instrument/VerifyLocalVariableTableOnRetransformTest.sh failed with "TestCaseScaffoldException: DummyClassWithLVT did not match .class file"
• 04f7112: 8266293: Key protection using PBEWithMD5AndDES fails with "java.security.InvalidAlgorithmParameterException: Salt must be 8 bytes long"
• a90b33a: 8266573: Make sure blackholes are tagged for all JVMCI paths
• ... and 5 more: https://git.openjdk.java.net/jdk/compare/2438498a3f6dfa53966a0f5b28af28617ca00e6b...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[YaSuenag]

Looks good! Thank you for fixing!

[kevinjwalls]

/integrate

[openjdk]

@kevinjwalls Since your change was applied there have been 30 commits pushed to the master branch:

• c6aa8f1: 8232644: bugs in serialized-form.html
• b5b3119: 8266589: (fs) Improve performance of Files.copy() on macOS using copyfile(3)
• 947d69d: 8265042: javadoc HTML files not generated for types nested in records
• 946b0fe: 8266645: javac should not check for sealed supertypes in intersection types
• 74fecc0: 8266503: [UL] Make Decorations safely copy-able and reduce their size
• 86b8dc9: 8265426: Update java.security to use instanceof pattern variable
• 3fcdc50: 8266646: Add more diagnostic to java/lang/System/LoggerFinder/modules
• 9a19a0c: 8264760: JVM crashes when two threads encounter the same resolution error
• 14f0afe: 8214237: Join parallel phases post evacuation
• 2798b0d: 8266349: Pass down requested page size to reserve_memory_special
• ... and 20 more: https://git.openjdk.java.net/jdk/compare/2438498a3f6dfa53966a0f5b28af28617ca00e6b...master

Your commit was automatically rebased without conflicts.

Pushed as commit 0790e60.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

[kevinjwalls]

(For the record, the tier1_serviceability tests run OK for me.)

[mlbridge]

Mailing list message from Laurence Cable on serviceability-dev:

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

On 5/6/21 1:48 PM, Kevin Walls wrote:

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[mlbridge]

Mailing list message from Laurence Cable on serviceability-dev:

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

On 5/6/21 1:48 PM, Kevin Walls wrote:

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