Re: [Nagios-db-devel] neb startup revisited

[Ben <be...@si...>]

On Wed, 26 Jan 2005, Matthew Kent wrote:

> In restart.sql (during nagios startup) I'm not quite clear on why an
> existing host and service should be reset back to a pending state by
> setting has_been_checked = FALSE. If you look at nagios and the standard
> cgis during startup, the data is read in from the retention file and the
> previous states for hosts/services is assumed to be correct.

Well, technically, the check *is* pending. I understand that the retention 
file says the host or service has a certain state, but that hasn't been 
verified. If nagios was simply restarted, then the retention data is 
likely accurate. But after a restart, it's entirely possible that nagios 
might have been down for days, and in that case the retention data is much 
more questionable. 

Frankly, I think it makes a lot more sense to label everything as pending 
until it's been checked. Weren't you the one that convinced me of that? :)

> Also in restart.sql, I'm not sure about inserting the empty host/service
> when one isn't found in the database. For example if you clear out the
> database and start nagios up the tac display will show X hosts with flap
> detection/notifications etc disabled which will slowly count backwards
> as all the checks complete. Kinda funky :)

Yeah, that's a serious hack. However, I'm not sure how else to record
services for a new host that has yet to be checked, because if there isn't
a placeholder record, then the service cannot be entered into the 
database. Perhaps I should set the host options to null, or some other 
"unknown" state.

> As I see it the solution for both issues would be to
> 
> - set configured = false for all hosts/services
> - do the 'select into thisHostID id FROM host WHERE name = hostName;'
> 
> if 
> the host/service is NOT found, send the object to processStatus like
> 
> /* update this host */
> nebstruct_host_status_data ds;
> ds.object_ptr=(void *)hl;
> 
> processStatus(NEBCALLBACK_HOST_STATUS_DATA, (void*)&ds);
> 
> which will set configured = TRUE, update the has_been_checked field etc.
> else
> we set host/service configured = true and assume the rest of the data in
> the db is correct and leave it alone (save the extra resources of
> running the stored proc)

I think a better idea would be to change configure_host() and
configure_service() to take in all the data we have on the host/service
before it gets checked, so that we can make our placeholder records more 
accurate.

> Come to think of it at this point you could actually 
> delete from host,service where configured = false 
> to prune any hosts that have been removed from the config.

I can't support deleting unconfigured hosts, because one of the
requirements my company has is to be able report on historical
availablity, even if the host isn't used anymore.

> This should give a more immediate overview of nagios's status right
> after startup.

Like I said, I think showing most things in a pending state shows the most 
accurate status. Well, actually, I suppose marking things as "Pending 
(assumed up)" or "Pending (assumed down)" and such would be the most 
accurate, but that could get messy.