Users experiencing intermittent 502 error message when trying to access bitbucket, bamboo and jira

[P]

As stated in the title. 

Users are experiencing this intermittent 502 error, that comes and goes away. 

I'm not sure on how to troubleshoot this, I was hoping the community may be able to recommend some things. 

We have only started to hear about this since we went offline - I think something is trying to access the internet and timing out - however it is holding on to the client request while it waits for this timeout. 

To expand more, we recently migrated our network to an offline network, meaning it cannot be reached via the internet. Could this be the source of these errors?

Anyway to pinpoint the culprit. 

[Daniel Ebers]

Hi Rob,

if it is not happening all the time it might be related to overload situations - probably due to high peak hours with users accessing the systems.

Are all of the three products behind a reverse proxy - probably the same? In other words, is the reverse proxy generating the 502 error?
If so, I would start looking into this first.

In case you have no proxy in front of the services I'd suggest to look into the logfiles first - one after the another and to compare if anything suspicious is recognizable by viewing them.

https://confluence.atlassian.com/bitbucketserver/bitbucket-server-debug-logging-776640147.html
https://confluence.atlassian.com/adminjiraserver/logging-and-profiling-938847671.html
https://confluence.atlassian.com/bamboo/logging-in-bamboo-289277239.html

The network change should not be related to it when the error only happens sometimes - in case it would have caused the issue I suspect the error would be of permanent nature.

In any case here comes the link with the general troubleshooting documentation for Jira (but the high-level steps apply for Bamboo and Bitbucket as well):
https://confluence.atlassian.com/jirakb/troubleshoot-performance-issues-in-jira-server-336169888.html

Cheers,
Daniel