[LON-CAPA-admin] Slowness in LonCapa

[Abdel Messeh, Maged]

Hi Stuart,

Two days ago we got some reports about slowness in LonCapa, I checked the server resources and nothing looked out of the normal.

This slowness was exhibited by two behaviors:

1. The discussion interface where we are seeing very long duration associated with both discussion posts and requests (this behavior apparently existed before we upgraded to 2.11.1 and deployed our lonBalancer).
2. Publishing, although not for all users.  The one example I have, is that a power user made minor edits on 11 or 12 resources and republished them, here are the times that he got from the time he hit "finalize publication" to the time the return page showed up (all in seconds):

40
40
130
90
15
15
15
8
90
15
12

While there is of course some variation in complexity of the prelabs he was publishing, we probably should not see that much variation in times.  The problem published was probably as complicated as any of the others.

Looking through the logs I noticed several times with: 

root at library1:/home/httpd/perl/logs# grep "CRITICAL: Forking server for s10.lite.msu.edu" lonc.log

23 times from around 10am till 5pm

I would appriocate any insights for where I can look for the cause of this problem.


Also on the resource allocation, we have:
Access servers - 12G RAM and 4vCPUs
Library server - 10G RAM and 8vCPUs

I am assuming that the balancer should have a lot less needs for memory and CPU? As it only directs traffic to one of the access servers?

Many thanks,

Maged