No data when polling maxfiles

[kkaramanolev]

Hello,
We are using zabbix 4.4 with Maxscale for DB HA.
There is issue which we noticed some of the host which item is without data. The item in question is configured to take kernel.maxfiles
Strange thing is that it is not experienced on all host only on some and it is only for this item. Other items are working fine.
On proxy during the problem with remote command data is showing fine.
As a workaround we noticed that fixing the issue is related to restarting maxscale service . After restart data is being populated.
Maxscale current configuration is as following:

[maxscale]
threads=auto

[server1]
type=server
address=server1
port=3306
protocol=MySQLBackend
priority=2

[server2]]
type=server
address=server2
port=3306
protocol=MySQLBackend
priority=1

[server3]
type=server
address=server3
port=3306
protocol=MySQLBackend
priority=3

# Monitor for the servers
#
# This will keep MaxScale aware of the state of the servers.
# MySQL Monitor documentation:
# https://github.com/mariadb-corporation/MaxScale/blob/master/Documentation/Monitors/MySQL-Monitor.md

[Galera Monitor]
type=monitor
module=galeramon
servers=server1,server2,server3
user=maxscale
passwd=zabbix
use_priority=true

# Service definitions
#
# Service Definition for a read-only service and
# a read/write splitting service.
#

# ReadConnRoute documentation:
# https://github.com/mariadb-corporation/MaxScale/blob/master/Documentation/Routers/ReadConnRoute.md


# ReadWriteSplit documentation:
# https://github.com/mariadb-corporation/MaxScale/blob/master/Documentation/Routers/ReadWriteSplit.md

[Read-Write Service]
type=service
router=readwritesplit
servers=server1,server2,server3
user=maxscale
passwd=zabbix
max_slave_connections=100%

# This service enables the use of the MaxAdmin interface
# MaxScale administration guide:
# https://github.com/mariadb-corporation/MaxScale/blob/master/Documentation/Reference/MaxAdmin.md

[MaxAdmin Service]
type=service
router=cli

# Listener definitions for the services
#
# These listeners represent the ports the
# services will listen on.
#

[Read-Write Listener]
type=listener
service=Read-Write Service
protocol=MySQLClient
port=3306

[MaxAdmin Listener]
type=listener
service=MaxAdmin Service
protocol=maxscaled
socket=default

[CLI]
type=service
router=cli

[CLI Listener]
type=listener
service=CLI
protocol=maxscaled
port=6603

Any help would be appreciated.

[kkaramanolev]

Noticed that is related with Zabbix history write cache which is decresing during the problem

[kkaramanolev]

Hello,
I can take any suggestions if you have.

Thanks,