Zabbix Configuration Cache

[Martins]

Hello all!

I don't know it is problem but I just want to understand zabbix better...
Today I checked zabbix server graphs which is provided by "Template App Zabbix Server" template and see that Zabbix Configuration Cache is below 25%. I read article and understand that this cache is needed to increase server performance, it is great. But on my situation free cache slowly but decreases over a time. I want to understand, why is so, I don't do a lot of changes in zabbix configuration and in frontend. After restarting zabbix server, Configuration cache is again ~ 75% free. At this moment I increased CacheSize to 16 mb, now free is 89%, but I want to understand why it is decreasing.



Thanks!

[nick0909]

That seems like strange behavior. My understanding is the cache is just your configuration, so it should be fairly static if you aren't adding or removing hosts/items/triggers/etc. My cache is directly correlated to how many hosts I have and how many templates applied to those hosts. Ex: if I add 5 hosts each with 100 items, 500 items are added to the configuration cache and it drops 10% (made up numbers, but you get the point). If I then remove those 5 hosts, the cache frees up 10%.

The only thing I can think of that is causing your steady decline is a discovery job that keeps rediscovering the same items and automatically adding more/multiple items for it, eventually filling up the cache. My cache free is shown below, you can see it is steady until I add or remove hosts, then it goes up or down. This is over a 3 month period as I was setting up my server, but there are long periods of flat times when no configuration changes happened and the cache didn't change, then I would add a bunch more hosts and it would drop some.