performance with mysqltuner

performance with mysqltuner

by mimi nom -
Number of replies: 2
Picture of Particularly helpful Moodlers

Hello,

Mysqltuner returned me this line among others:

[!!] name resolution is active : a reverse name resolution is made for each new connection and can reduce performance

and in the general recommendations it's written :

Configure your accounts with ip or subnets only, then update your configuration with skip-name-resolve=1

I didn't undestand the line above can I just add skip-name-resolve=1 in my.cnf file or do I have to do some configurations before


Than kyou in avance for your help




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In reply to mimi nom

Re: performance with mysqltuner

by Jeff White -

Looks like its suggesting getting a DNS resolution is slow which is a little odd. If you use physical IP address it does not need to do a lookup after the keep alive of DNS entry expires. I would check how long the keep-alive is for your server name to reduce the frequency your server needs to look it up. 


Check to see how long your query takes with: 

dig hostname | grep "Query time:"

In reply to mimi nom

Re: performance with mysqltuner

by Ken Task -
Picture of Particularly helpful Moodlers

In config.php, what do you have for DB server?
If 'localhost' that means DB server is on the same server as moodle code ... which to the DB server is a client.

Have you setup any workstation with the ability to directly access the DB server?

https://dev.mysql.com/doc/refman/8.0/en/server-options.html#option_mysqld_skip-name-resolve

https://dev.mysql.com/doc/refman/5.7/en/server-options.html#option_mysqld_skip-name-resolve

'spirit of sharing', Ken