Mongolian Timeout

[niranpr]

I found out that, for some unknown situation when concurrency increased in node, mongolian couldn't communicate with mongodb (timeout occurred). mongodb's health was fine so do node's health was also fine. but after restarted node, it went back to work properly for some period of time, and the problem rose again. I do load balance for 4 node instances, when mongolian of one instance was dead, the rest 3 were still fine and work properly. I though middleware got a communication problem with mongodb for some reason.

Anyway to track how this problem came from? is that because of some strange requests cause the single/shared mongolian object of that node instance went dead without returning error.

[marcello3d]

It's possible the connection is getting pegged in such a way that it thinks it's still connected. This could be a mongodb error over a mongolian error (perhaps the server thread is dead?). Can you use netstat, tcpdump, or similar to see if the connection is still there? Or perhaps log the requests and see which is the first one you get no response for?

There are no built-in timeout logistics in Mongolian right now, but you might consider restarting the connection if you don't get a response in a specified period of time. That's a bit of a brutish/band-aid solution, though.