Investigate flaky test parallel/test-zlib-convenience-methods

[addaleax]

• Platform: Ubuntu 14.04 (so far)
• Subsystem: zlib

https://ci.nodejs.org/job/node-test-commit-linux/21225/nodes=ubuntu1404-32/console:

13:26:19   ---
13:26:19   duration_ms: 0.227
13:26:19   severity: crashed
13:26:19   exitcode: -6
13:26:19   stack: |-
13:26:19     *** Error in `out/Release/node': free(): invalid pointer: 0x0ae0b5f8 ***

Might be helpful to have a core dump/binary pair (@nodejs/build)?

[refack]

stress: https://ci.nodejs.org/job/node-stress-single-test/1998/nodes=ubuntu1404-64/
https://ci.nodejs.org/job/node-stress-single-test/1999/nodes=ubuntu1404-64

[addaleax]

Stress test is currently at 5k/10k okay, 0 not okay. What happens if it comes back green? Do we close the issue and accept that this test fails every once in a blue moon?

[refack]

What happens if it comes back green?

I usually try some other parameters. If it's a parallel test, I add some of its neighbors to the mix (for example parallel/test-z*). An other option is to run it on the same host with the same exact code.

gist of log so we don't lose it https://gist.github.com/refack/0ec2aa4c53cb1e4c89a8f0ce9675f823

[addaleax]

Stress test did come back green, so, trying again: https://ci.nodejs.org/job/node-stress-single-test/2000/

[addaleax]

Now seeing on that platform (https://ci.nodejs.org/job/node-test-commit-linux/21266/nodes=ubuntu1404-32/console):

11:48:27 *** Error in `python': corrupted size vs. prev_size: 0x085f4498 ***

@nodejs/build I’d say there’s either something wrong with the OS, or the machine might have a genuine hardware issue.

[tniessen]

It crashed here as well: https://ci.nodejs.org/job/node-test-commit-linux/21645/nodes=ubuntu1404-32/console

13:10:10 not ok 2046 parallel/test-zlib-convenience-methods
13:10:10   ---
13:10:10   duration_ms: 0.228
13:10:10   severity: crashed
13:10:10   exitcode: -6
13:10:10   stack: |-
13:10:10     *** Error in `out/Release/node': double free or corruption (!prev): 0x0bbf36f0 ***
13:10:10   ...

[addaleax]

Yeah. It’s super weird how on the Node.js side, it’s only this one test that’s failing this frequently, when other programs seem to be having memory issues as well…

[Trott]

This hasn't been seen for a while, has it? Should it be closed?

[Trott]

This hasn't been seen for a while, has it? Should it be closed?