investigate flaky test-fs-stat-bigint

[Trott]

• Version: 14.0.0-pre
• Platform: FreeBSD
• Subsystem: fs, test

What steps will reproduce the bug?

Run test-fs-stat-bigint many times on FreeBSD.

How often does it reproduce? Is there a required condition?

It reproduces probably about 1% of the time.

What is the expected behavior?

The test should always pass.

What do you see instead?

The test sometimes fails with a block count of 1 vs 9:

AssertionError [ERR_ASSERTION]: 1n !== 9n
key=blocks, val=9
    at verifyStats (/usr/home/iojs/build/workspace/node-stress-single-test/nodes/freebsd11-x64/test/parallel/test-fs-stat-bigint.js:84:14)
    at /usr/home/iojs/build/workspace/node-stress-single-test/nodes/freebsd11-x64/test/parallel/test-fs-stat-bigint.js:127:7
    at FSReqCallback.oncomplete (fs.js:175:5) {
  generatedMessage: false,
  code: 'ERR_ASSERTION',
  actual: 1n,
  expected: 9n,
  operator: 'strictEqual'
}

Additional information

Seems to only reproduce on FreeBSD in CI, but I'm running a stress test to confirm.

https://ci.nodejs.org/job/node-stress-single-test/48/

[Trott]

It seems like I can't make it fail on test-digitalocean-freebsd11-x64-1 but can easily make it fail on test-digitalocean-freebsd11-x64-2.

@nodejs/build @nodejs/platform-freebsd

[Trott]

results on test-digitalocean-freebsd11-x64-2 showing 3 failures in 10000 runs for a failure rate of 0.03%. Maybe saying I can "easily" make it fail on that host was an overstatement.

I can't seem to get CI to kick off a stress test with test-digitalocean-freebsd11-x64-1 even though it's idle right now, but take my "it doesn't fail on that host" with a grain of salt. Maybe it's just failing at the same low rate.

[GeoffreyBooth]

#32280 (comment)

[GeoffreyBooth]

When I run python3 tools/test.py --repeat=100 -J parallel/test-fs-stat-bigint on my machine, I get 66 failures out of 100 attempts. MacOS 10.13.5, local Node built for #32280.

[Trott]

Stress test on FreeBSD showing 1 failure in 1000 runs: https://ci.nodejs.org/view/All/job/node-stress-single-test/85/nodes=freebsd11-x64/console

[complexsplit]

Is this issue stale, or still relevant?

[emaste]

Is it the case that file(s) used in this test are only from getFilename() - i.e., a tmp file named test-file-### that contains the string test? It seems very strange that we could get st_blocks=9.

[Trott]

https://ci.nodejs.org/view/All/job/node-stress-single-test/85/nodes=freebsd11-x64/console

Searching the automatically-generated test failure reports in the issues at https://github.com/nodejs/reliability/issues, I don't see this test failing any time recently. (Those reports were broken for a while but they started working again a two or three months ago.) I think we can close this (and re-open it if we see the problem recurring).