Optimisation/Optimization _ _ _

System software you can use to analyze squid
This is just a list of some of the programs that you can try using to figure out what is wrong with squid or the operating system that it is running on. Some of them may have different names, or may (in some cases) do different things. (strace is an example - on Linux it traces the system calls that a process calls, but on Solaris it does something "completely different".

strace (Linux) or truss (Solaris) trace system calls made by a process. You can trace an already running process with the -p flag.

top shows the amount of swap used and the percentage CPU used by each process.

vmstat shows lots of useful info as to CPU usage or disk/tty throughput and the amount read from or written to swap. It's best used as the command "vmstat 1", which shows the usage in the last second.

iostat (Solaris) shows the disk throughput of individual disks, so you can see if one disk is thrashing while another sits idle.

free (Linux) or swap -l (Solaris) will show you memory and swap usage.

netstat -na will show you information as to the sockets that your operating system is listening to (accepting new connections on) and other such info. You can figure out which IP address has those hundreds of connections open to you in an emergency with this.

The Squid Users guide is copyright Oskar Pearson oskar@is.co.za

If you like the layout (I do), I can only thank William Mee and hope he forgives me for stealing it