Problem with passive check

[KamiCrazy]

Hi,

I've been trying to troubleshoot this problem but I am not getting anywhere.

Basically if I use a FQDN in my agent config file for the Server= parameter my server can't connect to the agent.

On the server it reports ZBX_TCP_READ() [4] Interrupted System Call

However if I change the Server= parameter to an IP address instead, everything works.

Active checks appear to work just fine using a FQDN to connect to. From the agent I am able to do a reverse lookup on the IP and get the server's hostname.

From the server I am able to netcat to the agent with no problems and type random letters into the pipe.

Both server and agent machine use the same DNS server.

I am running zabbix 2.0.6, freshly built on SL 6.4

Any suggestions?

[KamiCrazy]

I just finished doing a bit more testing.

I installed a zabbix agent on Server 2012, put in FQDNs for Server= and ServerActive=

No issues whatsoever.

So whatever the problem is local to the SL 6.4 agent box.

[Heilig]

Message "ZBX_TCP_READ() [4] Interrupted System Call" indicating that a timeout has happened. Run this command on zabbix server "time zabbix_get -s sever_ip -p 10050 - k passive_key". Time of receipt result more than 3 seconds?

[KamiCrazy]

Hi thanks for the suggestion.

I ran the command once with an FQDN and once using IP.

Using an FQDN it takes 5 seconds for the query to return, using IP it takes 0.002 seconds.

So that appears to confirm there is a problem somewhere with timeouts.

Note that my zabbix server is connecting to the zabbix agent using IP only.

The only part which I would prefer to use an FQDN over an IP is in the zabbix agent configuration in the Server= parameter.

All I would imagine the agent doing is a reverse lookup on the IP to see if it matches the hostname. Interesting that it would take longer than 3 seconds on SL 6.4.

[Heilig]

The only part which I would prefer to use an FQDN over an IP is in the zabbix agent configuration in the Server= parameter.

This is the cause. Change to IP.