Questions on Trigger Actions

[stu42j]

It appears that Zabbix will only run one instance of an action script at a time, even if there are multiple triggers with the same action. Is this correct?

It also seems that Zabbix will retry the notification 4 times? Is this configurable? Also, how does Zabbix determine if the script was successful? Is there a particular way the script can return an error?

[alixen]

It appears that Zabbix will only run one instance of an action script at a time, even if there are multiple triggers with the same action. Is this correct?

Unless I misunderstand your question, this is not correct.
Action will be executed for each trigger.
If 10 triggers fire up at the same time, action script will be executed 10 times.

It also seems that Zabbix will retry the notification 4 times? Is this configurable?

From Zabbix source code:

frontends/php/include/defines.inc.php:  define('ALERT_MAX_RETRIES',             3);
include/common.h:#define ALERT_MAX_RETRIES      3

So you are right, notification will be executed at most 4 times (first try + 3 retries).
This value is hardcoded; you will have to recompile in order to change it.

Also, how does Zabbix determine if the script was successful? Is there a particular way the script can return an error?

At first, I supposed that Zabbix checked script exit value.
But after checking source code in src/zabbix_server/alerter/alerter.c:

                pid = zbx_fork();
                if(0 != pid)
                {
                        waitpid(pid,NULL,0);
                }
                else
                {
                        .... child process execution ....
                }
                res = SUCCEED;

exit value from child process is forgotten since return value from 'waitpid' is ignored and result is always set to SUCCEED.
So I assume that retries work only for internal actions (email, IM, jabber) but not for external scripts.

regards,
Alixen

[stu42j]

[QUOTE=alixen;60591]Unless I misunderstand your question, this is not correct.
Action will be executed for each trigger.
If 10 triggers fire up at the same time, action script will be executed 10 times.

If the action script takes a while to complete, I can see that there is only one process running and the actions for other triggers are listed as pending.

Thank you for your answers on my other questions.

[alixen]

If the action script takes a while to complete, I can see that there is only one process running and the actions for other triggers are listed as pending.

Thank you for your answers on my other questions.

OK, I misunderstood your question.
Since Zabbix doesn't check action script return value, you could run it in background so that zabbix is not blocked waiting for its end.

If your action script looks like:

#! /bin/sh
....
long_running_command
exit

You can replace it with:

#! /bin/sh
....
nohup long_running_command > /dev/null 2>&1 &
exit

Regards,
Alixen