[BUG] docker container crash caused by "SIGSEGV: segmentation violation" or "corrupted size vs. prev_size"

[MansuyDavid]

Description

one of our docker container regularly crash with this kind of messages SIGSEGV: segmentation violation.
and dump the whole memory stack after that.

Steps to Reproduce

I'm not sure this is easily reproductible, but this container monitores 14 databases, and 6 of them are not reachable (last messages before crash) so maybe this is linked.
version used is 2.0.4 for now.

time=2025-10-03T09:26:45.206Z level=ERROR source=collector.go:241 msg="Error pinging database" error="user=\"sys\" standalone params={authMode:2 connectionClass:<nil> connectionClassLength:0 purity:0 newPassword:<nil> newPasswordLength:0 appContext:<nil> numAppContext:0 externalAuth:0 externalHandle:<nil> pool:<nil> tag:<nil> tagLength:0 matchAnyTag:0 outTag:<nil> outTagLength:0 outTagFound:0 shardingKeyColumns:<nil> numShardingKeyColumns:0 superShardingKeyColumns:<nil> numSuperShardingKeyColumns:0 outNewSession:0}: ORA-12541: Cannot connect. No listener at host 10.1.1.1 port 1521.\nHelp: https://docs.oracle.com/error-help/db/ora-12541/" database=oracle_DBVISIT_DMDO

SIGSEGV: segmentation violation
PC=0x7f41da5f43e1 m=11 sigcode=1 addr=0x4e574f4e4b4e6d
signal arrived during cgo execution
...
[memory dump logs]
...
time=2025-10-03T09:27:45.631Z level=INFO source=main.go:75 msg="FREE_INTERVAL end var is not present, will not periodically attempt to release memory"

sometime i have this error :

time=2025-10-03T09:32:12.332Z level=ERROR source=collector.go:241 msg="Error pinging database" error="user=\"sys\" standalone params={authMode:2 connectionClass:<nil> connectionClassLength:0 purity:0 newPassword:<nil> newPasswordLength:0 appContext:<nil> numAppContext:0 externalAuth:0 externalHandle:<nil> pool:<nil> tag:<nil> tagLength:0 matchAnyTag:0 outTag:<nil> outTagLength:0 outTagFound:0 shardingKeyColumns:<nil> numShardingKeyColumns:0 superShardingKeyColumns:<nil> numSuperShardingKeyColumns:0 outNewSession:0}: ORA-12541: Cannot connect. No listener at host 10.1.1.1 port 1521.\nHelp: https://docs.oracle.com/error-help/db/ora-12541/" database=oracle_DBVISIT_DMDO

corrupted size vs. prev_size
SIGABRT: abort
PC=0x7fdcd3a555ef m=53 sigcode=18446744073709551610
signal arrived during cgo execution
...
[memory dump log]
...
time=2025-10-03T09:33:05.819Z level=INFO source=main.go:75 msg="FREE_INTERVAL end var is not present, will not periodically attempt to release memory"

Environment

• OS: docker container amd64
• Oracle Database version: 12 and 19
• Exporter version: 2.0.4 but I will upgrade to 2.1.0 asap to see if this changes.

to discuss

I don't know if you need the memory dump to help you on that.
I'm not even sure this must be investigated for now, because this issue happens only on 1 of my 13 container (the only one that monitore more than 5 DB). and the situation with 6 db not available can be linked to that.

I'm open to suggestions.

[anders-swanson]

Can you share the memory dump? I'd like to see where in cgo execution this failed. There are some known issues with godror/odpi-c that causes issues when managing largers numbers of connections.

[MansuyDavid]

Hello,

This is the last dump we had this morning.
oracle_exporter_dump.zip

as we are solving connection issues one by one It seems that the exporter is crashing less.
So it is probably linked to connection issues.

[MansuyDavid]

as shown bellow, decrease the connection issue seems to stabilize the exporter :

[anders-swanson]

I have noticed the godror driver crashes frequently when acquiring connections in a multithreaded environment. We have coded some workarounds but it is not quite stable it seems... I am thinking of implementing an alternate build that uses the go-ora driver, as it's a pure go driver without the need for CGO.

Once that is implemented, would you like to test the exporter variant with go-ora?

[MansuyDavid]

Yes i'll be happy to install it on my environments.

But if the actual stability increase with the connections setups (as shown in the graph) maybe I will not be able to detect a clear improvement with the new driver 🤷