Fixed in development branch svn://svn.zabbix.com/branches/dev/ZBX-4232 .
Maybe the massages:
6641:20111007:091459.168 Disabling Zabbix host [Zabbix server]
6641:20111007:091959.201 Enabling Zabbix host [Zabbix server]
could be improved too?
It's not clear what means that host is Disabling, Enabling. Sometimes this confuses me.
I recently ran into this problem.
What's your suggestion? "Disabling checks on Zabbix host [Zabbix server], no responce while processing item [system.uptime]"?
<Rich> dimir, if i recall correctly, several items can lead to disabling a host
<Rich> so giving item there might be a bit misleading
Couple of more suggestions.
<dimir> "Disabling checks on Zabbix Host [Zabbix server] until it becomes available"?
<Rich> "Temporarily disabling host [Zabbix server]" ?
I vote for
"Temporarily disabling checks on Zabbix host [Zabbix server]: host unavailable"
Any objections?
"Zabbix" in "Zabbix host" seems a bit redundant. either only "host", or "Zabbix agent host" (assuming it's for passive agents only ?)
"Zabbix" in "Zabbix host" is a host type. We have it everywhere so we know what "type of host" (item) is disabled. So this is dynamic. Another example:
"Temporarily disabling checks on SNMP host [Zabbix server]: host unavailable"
I don't know how exactly the disabling works depending of item types and if it really depends of types then i suggest something similar to:
"Temporarily disabling SNMP checks on host [Zabbix server]: host unavailable"
"Temporarily disabling Zabbix agent checks on host [Zabbix server]: host unavailable"
"Temporarily disabling ICMP checks on host [Zabbix server]: host unavailable"
Looks great. So, here is how it looks now:
25990:20111013:165818.574 SNMP item [snmp.uptime] on host [Zabbix server] failed: first network error, wait for 15 seconds
25995:20111013:165839.704 SNMP item [snmp.uptime] on host [Zabbix server] failed: another network error, wait for 15 seconds
25995:20111013:165900.736 SNMP item [snmp.uptime] on host [Zabbix server] failed: another network error, wait for 15 seconds
25995:20111013:165921.756 temporarily disabling SNMP checks on host [Zabbix server]: host unavailable
25995:20111013:170021.761 enabling SNMP checks on host [Zabbix server]
And if connection is restored before host is disabled:
26559:20111013:170913.022 SNMP item [snmp.uptime] on host [Zabbix server] failed: first network error, wait for 15 seconds
26561:20111013:170928.999 SNMP checks on host [Zabbix server]: connection restored
Same with Zabbix agent (many items):
26558:20111013:171008.264 Zabbix agent item [system.cpu.load[,avg15]] on host [Zabbix server] failed: first network error, wait for 15 seconds
26559:20111013:171008.264 Zabbix agent item [vfs.fs.size[/tmp,free]] on host [Zabbix server] failed: another network error, wait for 15 seconds
26561:20111013:171023.006 Zabbix agent item [vfs.fs.size[/tmp,free]] on host [Zabbix server] failed: another network error, wait for 15 seconds
26561:20111013:171038.008 Zabbix agent item [vfs.fs.inode[/opt,free]] on host [Zabbix server] failed: another network error, wait for 15 seconds
26561:20111013:171053.011 Zabbix agent item [net.tcp.service[pop]] on host [Zabbix server] failed: another network error, wait for 15 seconds
26561:20111013:171108.091 temporarily disabling Zabbix agent checks on host [Zabbix server]: host unavailable
26561:20111013:171208.101 enabling Zabbix agent checks on host [Zabbix server]
How's that?
For me this is great!
Perfectly !
awesome, except
"SNMP checks on host [Zabbix server]: connection restored" 
i think you the error message. how about "resuming..." ?
Well, I could not think of anything to add there but I guess "resuming" could be it. 
Fixed in pre-1.8.9 r22410, pre-1.9.7 r22412 .
Hello,
We had 55 minutes of not monitoring at one of our server (proxy02). We are using 1.8.10 which should solve this issue.
Do you know why this could be happenning?
$ grep proxy02 zabbix_server.log
11339:20130912:110557.170 Zabbix agent item [kern.sockets.orphan] on host [proxy02] failed: first network error, wait for 15 seconds
11342:20130912:115932.286 resuming Zabbix agent checks on host [proxy02]: connection restored
Thank you
PD: We will try to update our zabbix, I now this is a big NOT LOOK THIS COMMENT ...