[Linux-cluster] Centralized Cron

[Nick Burrett]

saju john wrote:
>  
> 
> Dear All,
> 
> Is there any way to make a centalized cron while using Redhat HA cluster 
> with Sahred storage. I mean to put the crontab entry for a particular 
> user on shared storage, so that when the cluster shifts, on the other 
> node cron should read from the cron file in shared storage.

If you want some form of high availability cron, you could try to 
leverage the Condor application to suit your needs.  If you link your 
cron applications against the Condor libraries, then you get process 
check pointing and all sorts of other wonderful stuff.


> This setup has the advantage that we don't need to manullay update the 
> cron entry in both nodes.

> b) Soft link the cron directory in /var/spool to 
> /path/to/shared/storage/cron. This is working till the cluster shift. 
> The cron is getting dead when the cluster shifts as it lose the 
> /var/spool/cron link's destination driectory which will be mapped to the 
> other node

You need to add in a heartbeat trigger.  The cron daemon runs on one 
server only.  When that server goes offline, then start the cron daemon 
on the backup server.  This is a terrible solution though.


Nick.