Server not registering value correct

[tomcan]

We have a very strange problem. We have a check that does a proc.num[mysqld] to count the number of MySQL processes. This check is part of a template and is attached to approx. 50 database servers.

On the last 3 servers we installed, Zabbix is triggering this check as the value returned (visible in latest data) is 0 instead of 1 although the processes are running. On the 47 other servers, the check is just working.

Now come the strange part. If we use tcpdump to inspect the data that is actually transmitted back to the zabbix server, it shows that it is sending the correct value (1).

Since this only occurs with the most recent databaseservers we setup, we would assume this is a client problem, or something that goes wrong when the server is added to Zabbix (through autoregistration/discovery).

We already tried updating both the Zabbix server as the Zabbix clients to the most recent version for Debian (3.4.5), but the problem remains. If we upgrade a working server to the most recent version of Zabbix client, the problem does not appear.

Does anyone have any other ideas on what goes wrong and how to fix this?

[tomcan]

Found the problem, appearantly the template item had a preprocessor active.

Not sure why this would only apply to new items and not to the existing items though... Removing the preprocessor from the item of the template fixed the problem for all failing hosts.