[katello-devel] Katello on 16 core box

[Lukas Zapletal]

Hello,

I did some testing today on a 16 cpu-core box and it turns out that 17 
thin instances can fill 2 gigs very quickly with a little help of pulp 
and candlepin processes.

After system tests are done every thin process consumes about 250 MB of 
memory from which about 30-100 MB of memory is not swapped (in use) if I 
read the top utility correctly. And please note our cli system tests are 
not performance tests or something - its like 150 individual API calls. 
No loops or something like that.

The box has 2 gigs of memory and it is swapping hardly. That sounds to 
me like we should have limit a maximum amount of thin processes to 
either a constant number or better

floor ( ((total_mem - reserve) / (cpu_count * 250m)) )

where reserve should be some decent amount of mermory allocated for 
non-thin processes (something like total_mem / 4).

ps - there is a nice bug - if you edit thin.yml and lower the number to 
let's say N there and then issue "service katello restart" it only 
restarts first N processes leaving the others still running :-) working 
workflow should be like:

# service katello stop
# vim /etc/katello/thin.yml
# service katello start

11022 tomcat    20   0 7426m 296m 3684 S  0.0 14.9   0:52.73 java 

10059 katello   20   0  249m 108m 2448 S  0.0  5.5   0:16.02 thin 

  9802 katello   20   0  245m 106m 2536 S  0.0  5.3   0:15.43 thin 

  9742 katello   20   0  245m 105m 2440 S  2.0  5.3   0:16.18 thin 

  9887 katello   20   0  245m 103m 2468 S  0.0  5.2   0:14.23 thin 

10023 katello   20   0  245m 103m 2364 S  0.3  5.2   0:14.05 thin 

  9738 katello   20   0  245m 101m 2532 S  0.3  5.1   0:15.54 thin 

10103 katello   20   0  245m  97m 2532 S  0.0  4.9   0:13.66 thin 

10091 katello   20   0  245m  96m 2436 S  0.0  4.9   0:14.56 thin 

  9763 katello   20   0  245m  94m 2460 S  0.0  4.7   0:14.65 thin 

  9771 katello   20   0  245m  84m 2428 S  0.0  4.2   0:17.32 thin 

  9995 katello   20   0  248m  51m 2444 S  0.0  2.6   0:16.08 thin 

10063 katello   20   0  245m  48m 2440 S  0.0  2.4   0:14.62 thin 

  9789 katello   20   0  245m  43m 2520 S  0.0  2.2   0:15.62 thin 

  9767 katello   20   0  244m  39m 2424 S  0.3  2.0   0:15.36 thin 

  9751 katello   20   0  244m  31m 2364 S  0.0  1.6   0:16.19 thin

-- 
Later,

  Lukas Zapletal | E32E400A
  RHN Satellite Engineering
  Red Hat Czech s.r.o. Brno