Zabbix showing SSH is down on all host and zabbix agent is unreachable

[Tek Chand]

Hello Team,

We are using Zabbix4.0 and it was working fine upto Dec 13, 2019. But in last two days we got lot of alert that SSH service is down on all host and Zabbix agent is unreachable over all host and its resolved automatically but it generate lot of alert during this time period and its very annoying.

We are monitoring 60 servers with zabbix and using passive check on all agent.

Below is the zabbix-server.conf file of my server with option which are enabled. We are using

LogFile=/var/log/zabbix/zabbix_server.log
LogFileSize=0
# PidFile=/tmp/zabbix_server.pid
PidFile=/var/run/zabbix/zabbix_server.pid
SocketDir=/var/run/zabbix
DBName=zabbix
DBUser=zabbix
DBPassword=xyz
StartPollers=80
StartIPMIPollers=10
StartPollersUnreachable=80
StartTrappers=20
StartPingers=10
SNMPTrapperFile=/var/log/snmptrap/snmptrap.log
StartDBSyncers=8
Timeout=30
UnreachablePeriod=120
UnreachableDelay=30
AlertScriptsPath=/usr/lib/zabbix/alertscripts
ExternalScripts=/usr/lib/zabbix/externalscripts
FpingLocation=/usr/bin/fping
Fping6Location=/usr/bin/fping6
LogSlowQueries=3000

Below is the screenshot of zabbix server graph at that time, which showing poller data collector process goes to 100%.



Below is the config of /etc/mysql/my.cnf file:

max_connections = 512

My zabbix server have 4 GB RAM and 2 CPU Core.

Can you please help me which config setting are need to change at server part?

Any help will be appreciated.

Thanks.

[Tek Chand]

Hello Team,

Can you please help me on above issue?

Thanks.

[Tek Chand]

Hello Team,

Can you please help me? I am waiting for some solution by experts.

Thanks.

[Hamardaban]

Perhaps the situation has to do with problems in the network. Look in the server log - there are probably a lot of messages about the unavailability of hosts.
Also pay attention to the situation with "queues". can help with identifying problematic items