replication / distributed monitoring

[tnk2k]

Hello All,

I'm very intrested in the Zabbix software however after reading the manual i raised the following questions:

1) If a distributed monitoring has been setup the parent will monitor some hosts and the child's will monitor some hosts, the data from these hosts is copied from child to parent and the data that the parent collects for other hosts is copied to the child?

2) Let's say the parent stops working for some reason, how will the affect the child? Will the child takeover the hosts that the parent was monitoring?

Thanks in advance.

[xs-]

1) yes, no
2) no

A distributed node is a fully autonomous, aka standalone, node.
The only thing a child node does is send configuration, trigger and history data to the master, and accept configuration changes from the master.
A child node has its own hosts, configuration, templates, users, groups, etc.

If a master node fails, the child node will continue to monitor its own hosts according to the configuration and send all data to the master when it comes back up.

If a child node does down, the master will not take over the monitored items.

[Alexei]

2) Let's say the parent stops working for some reason, how will the affect the child? Will the child takeover the hosts that the parent was monitoring?

The child will continue normal work. As soon as the parent is back, the child will send buffered information to the parent. Nothing will be lost.

Note that ZABBIX DM is not designed to move hosts from one node to another. The high availability has to be implemented on a node level, for each node individually.

[tnk2k]

So the best thing to do then is to monitor each host on every parent and child so the monitoring will be always done by atleast one?

[Alexei]

Well, the best thing is to ensure that ZABBIX Server is always available The DM setup will not be required in this case.

[tnk2k]

Yes i understand, but lets plan for the worst. We don't want an single point of failure and i really don't like nagios so i rather setup zabbix with some master/slave failover.

[tnk2k]

Hi,

I got into zabbix more, but this question still remains. I want a replicated setup with high availability c.q. an failover setup.

How could this be realized? In the normal dm setup there is always 1 master and we don't want an single point of failure?

[tnk2k]

Basically all i need is:

- that two servers idependetaly watch all hosts
- only 1 server (master) sends out an message if smth is wrong
- if the master dies the child takes over
- if the master is back the child gives master status again to master and synchronisez database?

[mfburgo]

My idea would be setup both servers monitoring all host. In the notification setup of the slave tell it to only send if the master is down.

if the master fails the slave will send if the slave fails the master will continue to send as it always did.

[tnk2k]

My idea would be setup both servers monitoring all host. In the notification setup of the slave tell it to only send if the master is down.

if the master fails the slave will send if the slave fails the master will continue to send as it always did.

Sounds good, but how to enable/disable notification automatically?

[tnk2k]

In nagios it's easy peasy

http://nagios.sourceforge.net/docs/2_0/redundancy.html

Can this be an feature for Zabbix aswell?

[niekie]

Sounds good, but how to enable/disable notification automatically?

AFAICS there is no provision in setting up an action to only execute based on some second item value (like "only send email when the master is down"). So if that is what you want to do, I would suggest you let the slave monitor if the master is up. Then write an action script that is invoked instead of just sending an email. Have that script check the Zabbix DB to see if the master is up. If it is up, then no further action is required. If not, have it send out your alert email.

Niek.

[Alexei]

AFAICS there is no provision in setting up an action to only execute based on some second item value (like "only send email when the master is down").

Why not? Create a "Master is down" trigger and use it for action conditions.

[niekie]

Why not? Create a "Master is down" trigger and use it for action conditions.

I always assumed that when defining action conditions, if you specify a trigger, it will actually perform the action when the conditions are met (e.g., in this case, when the master goes down it will perform the action).
The OP doesn't ask for an action when the master goes down, he asks for an action on any other trigger depending on whether the master is down at the time or not.

But to be honest I haven't tried this myself, so very likely I am wrong.