High CPU in mora and nginx after upgrade to 0.10 with external MongoDB

[mafiu]

Hi,

I recently upgraded API-Umbrella from 0.8 to 0.10 without problem, I've tested the aplication locally with local general_db.

The problem ocurred when I change the configuration to use an external mongodb server (In replicaset) and the CPU used by mora and nginx went too high (~100%) and doesn't go down.

In logs I can't see anything related to this.
Anyone has the same problem?

[GUI]

Hm, I can't think of anything that would be causing this off-hand, but what version of mongodb is your external replicaset running? How many nodes are in the replicaset? Is it using authentication, sharding, or any other configuration you can think of that differs from a stock mongodb setup?

[mafiu]

Hi Gui,

I've tested with mongodb 3.02 (with auth) and 3.2 (without auth), with 3 nodes and no sharding.
The same config was working on API-Umbrella 0.8

OS: CentOS 6 x64

[mafiu]

Hi Gui,

The problem is with mongodb 3+, I've tried with mongodb 2.6.11 and I don't have the same issue.
API-Umbrella 0.8 hasn't this problem.

[GUI]

Very strange. We've actually been doing all our testing of API Umbrella v0.9+ against MongoDB 3.0 (more specifically 3.0.7), so the fact that this is fixed by downgrading to 2.6 is odd. I don't think we're using any Mongo 3 functionality, so sticking with 2.6 should be fine, but it would be nice to understand what's going on.

I'll try to reproduce this with different setups, but in the meantime, do you know if anything was printed to the /var/log/api-umbrella/mora/current log file when this happened? You can also look in the logrotated files if you want to look back to the day this might have occurred (eg /var/log/api-umbrella/mora/current-20160109.gz). If anything is in that log file, that would be super helpful to know. Similarly, if you said nginx was also hogging CPU when this happened, I'd also be interested if there is anything in the nginx error log (/var/log/api-umbrella/nginx/current*).

[GUI]

Thanks for reporting this. I think I discovered what might trigger this scenario with regards to authentication. The bug causing high CPU usage should be resolved in the new v0.11 packages that are now out: https://github.com/NREL/api-umbrella/releases/tag/v0.11.0

However, there are some additional caveats with enabling authentication in MongoDB 3.0 (but these don't apply to 2.6, as I think you've discovered). I've added a new documentation page outlining the process for enabling authentication on 3.0, so hopefully that helps clear things up: http://api-umbrella.readthedocs.org/en/latest/server/db-config.html#mongodb-authentication

The bug was fixed in f01ebd2

Let us know if you're still seeing any issues or encountering any problems with an authenticated setup.