Constant Zabbix Unavailable for 5 minutes

[dsgnr]

Hi everyone,

I have a fairly small install of Zabbix on my home lab. Currently monitoring 17 hosts, with a current total of 1533 checks. I am constantly getting the dreaded Zabbix Agent Unavailable for 5 minutes triggers. This is consistent with constant gaps in the graphing.

All hosts, except 2 are on either the same hypervisor, or on another hypervisor connected via 10GB networking. There are 2 that are hosted at places like Digital Ocean.

I have only started experiencing this since upgrading to the latest version of Zabbix Server (3.4.2).

I have increased the timeout on both the server, and the agent to the max (30 seconds). I have also increased the poller and mysql configuration on the server but I am still receiving this.

Is there anything else to look for to resolve this? I'm getting a few hundred emails an hour from each host and it's getting rather comical lol

Thanks!

[kaspars.mednis]

Hi !

I have also increased the poller and mysql configuration on the server but I am still receiving this.

so the pollers are enough on zabbix_server ?
the Zabbix busy poller processes, in % must be <100% at all times

And have you increased the mysql max_connections on mysql DB ? i remember having problems with those after some migration to zabbix 3+

maybe zabbix_server log is showing the problem ?

best regards,
Kaspars

[dsgnr]

Hey

The busy poller process is max 1.7%

All I can see in the zabbix server logs is ‘first network error, wait for 300 secknds’ Then a connection restored shortly after.

This is constantly happening tho. I receive a problem email seconds after a timeout email for this

[kaspars.mednis]

On mysql side, what is the number of max_connections ?

mysql> SHOW VARIABLES;

| max_connections | nnn |

and how many connections are you getting ?

try

sudo netstat -antp | grep :3306 | wc -l

where 3306 is your mysql port, or something like this

I have got similar problems in the past with this

regards,
Kaspars

[dsgnr]

Max connections is currently set to 1000.

Thanks

[kaspars.mednis]

If the mysql_coonections are enough, at the moment i can only suggest

check your mysql log for any errors
take a look at all zabbix server items (pollers, caches. etc) maybe there is some processes too busy...

regards,
Kaspars

[allexpetrov]

Hi,

What you actually mean under *mysql configuration* ?

What is in zabbix log files ? You can find them under /var/log/zabbix/zabbix_server.log and ~/zabbix_agentd.log

Is it happening only with one host or with multiple?

Regards,
Alex!

[dsgnr]

looking in the mysql error logs, there are no errors.

None of the zabbix server graphs are showing high usage at all - if anything, they're too low. At like 1% utilisation.