Host Unavailable, No data collected.

[Jasper]

Hello,

I just finished installing Zabbix on Linux.
I am new to Zabbix!

I have configured one host. And Two Items.
Items configured are:

1. Name: ActiveSession / Type: JMX agent / Key: jmx[jboss.web,activeSessions]
2. Name: Uptime / Type: SNMPv3 agent / Key: hrSystemUptime.0
(There is a green tick against both items)

Questions
========
1. The host is showing as Monitored but Unavailable. Why?

2. There is no data being collected at all.

3. How can i restart zabbix_server.
I had started it as follows:
$ /usr/local/sbin/zabbix_server

But i cannot find anyway to stop or restart.

4. In /tmp/zabbix_server.log is see among other messages:
[Z3005] query failed: [2006] MySQL server has gone away [begin;]

What does it mean.. zabbix UI is successfully coming up... so whats wrong with the DB here?

Looking forward to help from experts! Where should i look for problems.
Thanks.

[heaje]

3. How can i restart zabbix_server.
I had started it as follows:
$ /usr/local/sbin/zabbix_server

But i cannot find anyway to stop or restart.

You'll have to manually kill the process since you aren't using any sort of init script. Do a "ps -eaf | grep zabbix_server" and then kill every zabbix_server process listed. There are faster ways to do that, but I don't have time right now to write up a minor command to do that.

4. In /tmp/zabbix_server.log is see among other messages:
[Z3005] query failed: [2006] MySQL server has gone away [begin;]

The UI uses a different configuration file than zabbix_server. It is possible you have the incorrect mysql information in your zabbix_server.conf file. I would double check you have the correct information there. Also, double check that you don't have to specify the configuration file zabbix_server should use when you start it up (run zabbix_server --help to get a list of command line parameters).