restart rsync process via shell script

[Matt McCutchen]

On Mon, 2008-12-29 at 08:13 -0800, Noah wrote:
> I am trying to figure out the most accurate way to assess if an rsync 
> process is running and is established to the remote rsync server and is 
> transferring data.  I am writing a bourne shell script to restart rsync 
> if the connection to the remote rsync server is lost.

Try the --timeout option, which will make rsync exit if no progress is
made for a specified time period.  This is probably easier and more
reliable than coding your own timeout.

> The command "ps ax | grep 'rsync' | grep -v grep"  is not enough because 
> the rsync and ssh process can be running but the connection to the 
> remote server is no longer ESTABLISHED and the backup is no longer 
> proceeding.
> 
> Then perhaps the command "netstat -A | grep '192.168.1.10' | grep 
> 'ESTABLISHED' | grep -v grep" would be helpful.  But in some cases I 
> have found that I have ssh connections to the remote rsync server that 
> obfuscate the rsync ssh ESTABLISH statistics.

If you decide to go this route, you can get the pid of the ssh process
holding the connection by passing --program to netstat and then check
whether its parent (for the local ssh) or child (for the remote ssh) is
an rsync process.

-- 
Matt