Cacti Agent that stores data offline at node

[ketan985]

I would like to request feature like cacti Agent.

Normally If connection between cactiserver and Node will be fail, cacti will declare that node as down.

I want to apply mechanism that cacti agent at node will check snmp data connection between server and node, if connection breaks then that cacti agent starts collecting data offline at that node, after connection reset to the cacti server , it will submit all gathered data to the server , cacti server will create graph from that data or add that to the graph. So Administrator can get idea what were server's statics when when there was no connection.

I think it will very helpful.


Ketan K. Patel

[victorantunes]

I may be wrong here, but I suppose that's doable by writing a script that pings Cacti, and when it fails, starts doing SNMP queries.

However, the main problem I imagine there to be is the one concerning time synchronization. The reason is because you'd also have to store, on the client side, the precise timestamps for those SNMP queries, so that when Cacti comes back online it'll know where to place that data on the .rrd file.

(In case you're not familiar, rrdtool not only needs to know the data itself, but it also needs a timestamp associated with that data)

And of course, after all of the above works, you'd also need to implement a server-side routine to do that kind of custom batch inserting on the .rrd's (which I believe Cacti currently doesn't have).


OR


you could implement a High Availability Cacti cluster, so that when one instance of Cacti fails, there'll be another one to take its place.


All in all, it's an interesting idea you have.

[ketan985]

You have point out important thing, We can set GMT time at both sides (On Cacti-server and Node), so there will be no problem of synchronization.

[JJX]

This agent isn't necessary only if cacti server fails but also if you monitor a remote site and there is a problem with the network (link fails, no backup , etc)

A similar agent exist for an other vendor, but only collects data for 5 minutes (that I find it really stupid).

I think the tough part will be how to merge "out of sync" data when connectivity is back

In case this get implemented will be great!