> How can i take some measurements to understand what bottlenecks will
> appear?
For long-term / ongoing I'm very happy so far with a package called
munin. Google it and join their mailing list for help setting it up.
But it takes snapshots at 5 minute intervals and this is not configurable.
For immediate-term and for doing load tests, I've been very happy with
sar/sadc from the "sysstat" package that you can get from yum. And
also a package called ksar that you can google and download.
From our wiki :
---snip---
Before starting your load test, start this command on all boxes you
want to monitor
/usr/lib/sa/sadc -d -I -F 2 /var/log/foo/bar
or on a 64 bit box
/usr/lib64/sa/sadc -d -I -F 2 /var/log/foo/bar
It will log system stats at 2 second intervals, until you control-C it.
Then you can view the file in kSar.
* go to "File" then "New Window"
* from the new window go to "Data", "Local Command"
* enter the command sar -A -f /var/log/foo/bar
That's it! Now you will have some pretty graphs to look at!
--
“Don't eat anything you've ever seen advertised on TV”
- Michael Pollan, author of "In Defense of Food"
