Re: Steadying monitoring processes without starting them

[Sandy C]

Hi Dominic,

Thanks for the reply and for the decoding of type-o's - typed the email on a 
phone.

But the suggestion doesn't quite address the use case we are trying to get to 
if I am understanding it correctly.

Maybe I am thinking about this wrong.  Here is a short background/outer use 
case:

We are orchestrating a cluster (a bunch of machines) with various app stacks 
that have all the colors of the rainbow when it comes to start/stop/management. 
 Some app stacks can start on N nodes independently while some are very 
sequential and start only from a single master.  Such as say hadoop or accumulo.

So for this latter camp, say accumulo, we can use monit to start/monitor/manage 
the master node which will start the slave apps (tservers) on the slave nodes.

The difficulty is figuring out how to start monit on the slave nodes such that 
it will NOT start the tserver process but will only monitor it once it is up, 
and then restart it if it goes down.

But, we do not want the monit on the slave to bring up the tserver until the 
master brings it up.  Which could be days/weeks/ a long time.

The goal was to do this without having to manage monit itself (as it take monit 
down or have monit reload new config files when/if the accumulo master starts).

But I can't yet see how to make that happen.

Hope this helps.  Thanks in advance for additional replies (from anyone).

-sandy

> On May 13, 2016, at 14:13, Dominic Harkness <address@hidden> wrote:
> 
> You may be able to add a condition like "if does not exist" that will 
> override the restart if the process isn't running. I'm not sure if you can 
> avoid monit logging every time it sees the process does not exist, though.
> 
> For example, if you want monit to double check before issuing a restart you 
> could say: "if does not exist for 2 cycles then restart". It will log that 
> the process was not running in the first cycle and then restart the process 
> if it's not running in the second cycle as well.
> 
> Hope that helps!
> Dominic