Re: High load average every 105 minutes - Mailing list pgsql-general

From Chris Mair
Subject Re: High load average every 105 minutes
Date
Msg-id 190177ade9dfc82e5b9de575910e1e9c@smtp.hushmail.com
Whole thread Raw
In response to Re: High load average every 105 minutes  (Nhan Nguyen <nhan.nguyen@inspireventures.com>)
List pgsql-general
>> with AWS, your system is sharing the vendors virtual machine environment with other customers, and performance is
prettymuch out of your control. 

> I found no strange processes or queries while load average was at peak. IO also didn't change. Some more slow queries
werelogged, but not many. 
> I think sharing the VM with other customers doesn’t have much to do with this. I checked my other servers too, and
onlythose that have postgresql have the load average issue. Generally it doesn’t impact my system much, but when there
areslow queries, this issue just makes everything worse. 

Hi,

generally speaking AWS is pretty good at isolating users (and you can request single tenancy machines or
dedicated machines as well if you're concerned about this).

However, if you're running t1 or t2 instances, you get the concept of CPU credits. When those run out, your
system is slowed down until the credits recover. I could imagine that this way some cyclic load patterns
emerge, if there is constant load on the machines.

Nhan, what instance types are you running?

Bye,
Chris.





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