Go routine memory allocation issue

[rlagyu0]

error emit like below

ts=2025-02-25T07:55:33.803Z caller=collector.go:511 level=debug msg="Calling function ScrapeGenericValues()"
ts=2025-02-25T07:55:33.803Z caller=collector.go:616 level=debug msg="Calling function GeneratePrometheusMetrics()"
double free or corruption (out)
SIGABRT: abort
PC=0x7f756d1235ef m=0 sigcode=18446744073709551610
signal arrived during cgo execution

Typically, it fetches data successfully for the first 2-3 times, but it seems that during the memory allocation/deallocation process of goroutines, they get tangled, leading to issues with duplicate memory allocation or deallocation. Please provide your opinion.

[RainerW]

Same problem, with 1.5.3, but 1.5.2 seems to work.

[markxnelson]

thanks @RainerW - i think we are narrowing in on the issue. seems to only happen with godror 0.46.0 and later, not earlier versions. doing more debugging to try to isolate the root cause

[anders-swanson]

See: godror/godror#361

[anders-swanson]

In testing, using connection pooling parameters resolved the issue. However, let's see what godror maintainers think :)

[markxnelson]

We believe we have this fixed in 1.5.4 - if you still see the error, please reopen, or open a new issue to let you know. Thanks very much for your input.

[VictorErmakov]

@markxnelson, unfortunately I still face this issue in 1.5.4

[anders-swanson]

@VictorErmakov can you share the parameters used for the exporter, as well as the following details about the environment you're running it on:

• OS
• Architecture
• Containerized or bare metal/VM?
• version of instant client
• version of glibc

In my testing, I found that increasing the maximum idle connections can resolve this problem:

      --database.maxIdleConns=10
      --database.maxOpenConns=10

[VictorErmakov]

@anders-swanson
OS: Ubuntu 22.04.3 LTS
Architecture: x86_64
Container: docker-compose
glibc: ldd (Ubuntu GLIBC 2.35-0ubuntu3.9) 2.35

Following parameters helped! At least it does not throw an error in the first 10 minutes!

Probably it should be added in the example compose file.

Thanks!

[anders-swanson]

Perfect, thanks for opening the PR. I am hopeful future versions of godror will handle this better too.