where set max_connections for DB ?

[FildaSmile]

Hello,

(ZBX 4.4)

i had problem with zabbix error: Zabbix unreachable poller processes more than 75% busy, i find that i should raise value for "StartPoller=" in "/etc/zabbix/zabbix_server.conf", i did it but suprisingly it didnt help and the problem was actually worse. (100% load of poller)

I found that it is not about raising this value :

First of all, I tried out to increase the number of pre-forked instances of pollers for the Zabbix server, that is, I changed its default value from 5 to 256 (remember that for that case, you have to set the the number of maximum connections in MySQL - max_connections - higher than 256, since every single poller opens a dedicated connection to the database) (source: http://redes-privadas-virtuales.blog...han-75_28.html )

Unfortunately my "my.cnf" /etc/mysql/my.cnf does not contains max_connections. Can you please help and advice me where i can set this value ?

It is true that everytime when i want raise Start poller i must raise also DB max_connections ?

Thank you !

[Hamardaban]

“startpoller” is not the parameter that controls “unreachable poller”. Guess what the parameter responsible for unreachable poller should be called? :-)
If you can't guess - read https://www.zabbix.com/documentation.../zabbix_server
(hint - StartPollersUnreachable)

Mysql server settings may differ depending on the version, and the location of the configuration file depends on the operating system version. Refer to the documentation and use the file system search.

[FildaSmile]

im sorry it was my mistake i copied wrong text it should be : Zabbix poller processes more than 75% busy instead of Zabbix unreachable poller processes more than 75% busy, sorry so this is the reason why i found that article -> it has same error message in the title.

[Hamardaban]

Each poller may require a connection to the database.Therefore, the more poller is running, the more connections you need to allow on the DB server.
But a large increase in the number of poller can negatively affect the operation of the entire system! increase in small portions, not in a sudden jump (5=>10, 10=>15, not 10=>100)
By default mysql have 150 max_connection

[FildaSmile]

got it - i did sudden jump and system became very unstable so at least i have experience, i wirte back defaults and it work again, next time i want do it correctly, but in which DB conf file i can find "max_connection" value ? i tried my.cnf but there is nothing such max_connection - that is the main question in this thread, thank you very much !

[FildaSmile]

Hello i figured out how set max connections, f.e. SET GLOBAL max_connections=200; , do you have any practice in ratio between max_connections and pollers ?? when i want raise pollers how much i should raise max_connections ?

[Hamardaban]

max_conn>=poller_count

[FildaSmile]

you mean "StartPollers=28" from " /etc/zabbix/zabbix_server.conf" ? because i did not find "poller_count" in "mysql" :

MariaDB [(none)]> SHOW VARIABLES LIKE 'poller_count';
Empty set (0.01 sec)

Thank you so much !!!!

[a.naderi]

Hello i figured out how set max connections, f.e. SET GLOBAL max_connections=200; , do you have any practice in ratio between max_connections and pollers ?? when i want raise pollers how much i should raise max_connections ?

Hello
I have same issue like you and I don't know where should I set MAX_CONNECTION !
CENTOS7 and Zabbix 5.0

Zabbix poller processes more than 75% busy and it's 100% now... I changed StartPollers to 256 but nothing!
can you please advise me ?