DB max allowed packet size

Question

In Confluence Administration, (Menu : Administration -> Support Tools - Instant Health)
I saw the message

'Max Allowed Packet'

-> checks if the max_allowed_packet variable in your MySQL database is appropriate.

-> change max_allowed_packet variable to 34M

(https://confluence.atlassian.com/confkb/exceeds-max-allowed-packet-for-mysql-179443425.html)

So I changed the max_allowed_packet variable 16M to 32M as maria DB
recommendation (two times 16M).

Is it a must to change the max_allowed_packet variable size to 34M?

If it is difficult to change, what is the result?

Gonchik Tsymzhitov · Answer

Unfortunately, in my experience I have set different values for mysql, percona - different values not multiple of 2.

And in documentation in Maria DB, I have not seen any info about multiple of 2.

https://mariadb.com/kb/en/library/server-system-variables/#max_allowed_packet

For my instance have set max_allowed_packet = 256M

Because it is need for faster backup.

Hence you can set 64M, for to be in deal with your system administrator:)

Cheers,

Gonchik Tsymzhitov

YongDuk Kim · Answer

Thank for your reply.

But I want to know what value is max_allowed_packet variable?

In confluence system, it recommend to set 34M,

but system administrator in my confluence server recommend max_allowed packet size in maria DB is multiple of 2, so 32M.

Is it 34M or 32M?

Gonchik Tsymzhitov · Answer

Hi!

* You need to change max_allowed_packet  in my.cnf, by default it is located in /etc/my.cnf
* After change parameter you need to restart mysql. before stop your confluence instance. 
* That's all

Info:

https://dev.mysql.com/doc/refman/5.7/en/packet-too-large.html

https://stackoverflow.com/questions/8062496/how-to-change-max-allowed-packet-size/8062996

Cheers,

Tsymzhitov Gonchik