Initial request to server extremely slow after longer periods of inactivity

opendaddy at opendaddy at
Sat Apr 11 15:54:49 UTC 2015


On 10. april 2015 at 9:01 AM, "Raimund Sacherer" <rs at> wrote:
>Then what I would do in your case is open a few ssh sessions, run 
>top with cpu focus in one, top with IO focus in another and in a 
>third i would take a tcpdump written to a file. Maybe another 
>session with vmstat to check on pagin/pageout, etc. 
>Then I'd wait the appropriate amount of time and try a web 
>connection, if it takes long, I'l check the top's if there is 
>something going on (lot's of CPU, lot's of IO, pages etc.) and 
>check the tcpdump in wireshark to see if there are problematic DNS 
>queries which maybe are timing out, etc.

Wouldn't SSH sessions act as "continuous feedback loops" preventing the server from going unresponsive in the first place?

Also, how can I do stuff like `traceroute` or `mtr` knowing beforehand that the server is indeed unresponsive? Since it's only unresponsive on first requests, if I send a request to check, things will have returned to normal by the time I get to run those commands.



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