John Sidney-Woollett wrote:

> check_slon checks to see that the slon daemon is in the proces list 
> and optionally checks for any error or warning messages in the slon 
> log file
> it is called using two or three parameters; the clustername, the 
> dbname and (optionally) the location of the log file. This script is 
> to be executed on each node in the cluster (both master and slaves)
>
> check_sloncluster checks that active receiver nodes are comfirming 
> sync within 10 seconds of the master. I'm not entirely sure that this 
> is the best strategy, and if you know otherwise, I'd love to hear. 
> Requires two parameters;  the clustername and the dbname. This script 
> is executed on the master database only.
>
> These scripts are designed to run on the host on which they are 
> checking. With a little modification, they could check remote servers 
> on the network. They are quite simplistic and may not be suitable for 
> your environment. You are free to modify the code to suit your own needs.
>
> John Sidney-Woollett

I have modified them for portability (I think they were somewhat BSD 
specific, if I had to be pressed for a guess...), and have extended the 
latter one to be able to run remotely.

Both look like good ideas...