There are many cases that could lead OpenDJ to stop working. Customizations in gluu server (attribute, custom scripts, etc), lack of resources, network failing, etc. If we fail to log in gluu server, then we first check the `OxAuth` logs. after then each of others logs according to `OxAuth` logs.
Ref:
* https://gluu.org/docs/gluu-server/4.3/operation/logs/
* https://gluu.org/docs/gluu-server/4.3/operation/faq/
Thanks,
Regards ~ Shakil