CPANEL-35991 - Bug in MySQL 5.6 to 5.7 upgrade (error log)?

[ffeingol]

We've been performing MySQL 5.6 to 5.7 upgrades for some of our clients.

In MySQL 5.6 the --log-error is passed on the command line when MySQL is started. With MySQL 5.7 it's missing. I can see in the /etc/my.cnf.rpmnew file that there is a log-error=/var/log/mysqld.log set, but the upgrade is not merging that into /etc/my.cnf so it's not getting set.

On servers that just had MySQL 5.7 installed I can see the line in /etc/my.cnf, so this "seems" like a bug?

 

[cPRex]

Hey hey,

Can you try running this?

mysql -e "show variables" | grep log

That would let you know if MySQL has that variable included. I do see that on a system that I upgraded from 5.6 to 5.7.

 

[ffeingol]

None set so it's defaulting to stderr:

# mysql -e "show variables" | egrep log_error
binlog_error_action     ABORT_SERVER
log_error       stderr
log_error_verbosity     3

I've been able to reproduce this on every system we've upgraded from 5.6 to 5.7

 

[cPRex]

Interesting - are they all a certain OS, or is it a mix of 6 and 7?

 

[ffeingol]

I believe all the ones we have done recently are CentOS V7.

While it's easy enough for us to add:

log-error=/var/log/mysqld.log

to my.cnf, this "seems" like something that the upgrade script should be taking care of.

 

[cPRex]

Let me do a test and I'll let you know what I see :D

 

[cPRex]

I created a CentOS 7 machine, specified that I wanted MySQL 5.6 on it, ran the cPanel installer, performed an upgrade to MySQL 5.7, and I confirmed the issue.

I've created a case with our developers so they can look into this a bit more and I'll post an update here once I have one.

 

[cPRex]

@ffeingol - our devs did some more testing with this and found this is the default value included with MySQL 5.7, so you're just seeing the default value change.

If the value is applied to /etc/my.cnf, that gets retained during the update, but the change isn't something special we're doing on the cPanel side of things as that's all handled with the MySQL upgrade process.

 

[ffeingol]

Ok, then this doc needs to be updated: The cPanel & WHM Log Files | cPanel & WHM Documentation with a qualifier that it will be in /var/log/mysql.log if you did a fresh install of MySQL 5.7, but if you upgrade, it wont' be there ;-)

We'll just add:

log-error=/var/log/mysqld.log

to /etc/my.cnf on the upgrade servers, but it would have been nice if the upgrade actually took care of this.

I know this is the way that things are distributed by MySQL/Oracle, but it's a bit frustrating that things are inconsistent on an install vs upgrade.

 

[cPRex]

Agreed on all counts - I've already got an update in with documentation to get that changed.