Where is my mysql log on OS X?

Question

I checked /var/log and /usr/local/mysql and i can't seem to find the log. I am trying to troubleshoot an error establishing a database connection with a php function.

Answer 1

As Chealion mentioned, there are several ways that your mysql could have been installed. Each of which will place your data dir and/or logs in different locations. The following command will give you (and us) a good indication of where to look.

ps auxww|grep [m]ysqld # Putting brackets around the first char is a `grep`+`ps` trick # to keep it from matching its own process. # Note: For zsh compatibility put quotes around the grep regex 

Can you post the result of that command here please? Mine looks like this:

_mysql 101 0.0 0.3 112104 13268 ?? S 12:30AM 0:13.20 /opt/local/libexec/mysqld --basedir=/opt/local --datadir=/opt/local/var/db/mysql --user=mysql --pid-file=/opt/local/var/db/mysql/rbronosky-mbp.pid root 76 0.0 0.0 600172 688 ?? S 12:30AM 0:00.02 /bin/sh /opt/local/lib/mysql/bin/mysqld_safe --datadir=/opt/local/var/db/mysql --pid-file=/opt/local/var/db/mysql/rbronosky-mbp.pid 

From that you can see that my datadir is /opt/local/var/db/mysql (because I installed via MacPorts). Let's take this lesson a bit further...

From the first line you can see the my daemon is /opt/local/libexec/mysqld. The mysqld can be called with --verbose --help to get a list of all command line options (and here is the important/valuable part!) followed by the values that would be used if you were launching mysqld instead of just checking the help output. The values are the result of your compile time configuration, my.cnf file, and any command line options. I can exploit this feature to find out EXACTLY where my log files are, like so:

/opt/local/libexec/mysqld --verbose --help|grep '^log' 

Mine looks like this:

log /tmp/mysql.log log-bin /tmp/mysql-bin log-bin-index (No default value) log-bin-trust-function-creators FALSE log-bin-trust-routine-creators FALSE log-error /tmp/mysql.error.log log-isam myisam.log log-queries-not-using-indexes FALSE log-short-format FALSE log-slave-updates FALSE log-slow-admin-statements FALSE log-slow-queries (No default value) log-tc tc.log log-tc-size 24576 log-update (No default value) log-warnings 1 

LO AND BEHOLD! all of the advice in the world was not going to help me because my log file is kept in a completely non-standard location! I keep mine in /tmp/ because on my laptop, I don't care (actually I prefer) to loose all of my logs on reboot.

Let's put it all together and make you a oneliner:

$(ps auxww|sed -n '/sed -n/d;/mysqld /{s/.* \([^ ]*mysqld\) .*/\1/;p;}') --verbose --help|grep '^log' 

Execute that one command and you will get a list of all of the logs for your running instance of mysql.

Enjoy!

This Bash-Fu brought to you for free by my commitment to all things Open Source.

Answer 2

There are 3 types of MySQL/MariaDB logs:

• log_error for the error message log;
• general_log_file for the general query log file (if enabled by general_log);
• slow_query_log_file for the slow query log file (if enabled by slow_query_log);

Check the settings and location of above logs by this shell command:

mysql -se "SHOW VARIABLES" | grep -e log_error -e general_log -e slow_query_log 

By default the logs are stored in your data dir, so check location by this shell command:

mysql -se "SELECT @@datadir" 

To view your error log, you can run:

sudo tail -f $(mysql -Nse "SELECT @@log_error") 

If you've general log enabled, to view it, run:

sudo tail -f $(mysql -Nse "SELECT CONCAT(@@datadir, @@general_log_file)") 

Answer 3

Another way to find this information is to use lsof.

1. Use Activity Monitor to find the PID of mysql, or use ps -ef | grep mysqld to find it.

2. sudo lsof -p PID_OF_MYSQLD and see which files MySQL has open.

Answer 4

Took myself a while to find this... try this location:'

sudo vi /usr/local/mysql/data/YOUR-USERNAME.local.err 

Answer 5

By default, all log files are created in the mysqld data directory.

Source: MySQL Documentation

You can use mysqlbinlog to read the binary log files in /usr/local/mysql/data/ (in my installation not all were binary). Some errors are simply directed to stderr so you may want to check /var/log/system.log as well.

Answer 6

The folder holding that log may not be accessible to you without using sudo:

sudo ls -l "/usr/local/mysql-5.0.51a-osx10.5-x86" [..] drwxr-x--- 4 _mysql wheel 136 Jul 10 23:06 data 

If you happen to find a large log file and when you're using Time Machine, you may want to read What is Time Machine doing? on Server Fault.

Answer 7

By default, all log files are created in the mysqld data directory. Unfortunately, many people don't put their log files (and programs) in their typical locations. I'm one of them!

I went through this routine myself with MySQL until I tried out Navicat for MySQL. Later I upgraded to Navicat Premium. Both have a Monitoring tool that contains a tab with all of the server variables in one comprehensive list. Here's a screenshot with the log_error server variable:

log_error server variable in Navicat Server Monitoring Tool

You can also set the variables right there in the list.

Cheers!

Answer 8

1. Open System Preferences

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2. Select MySQL -> Configuration

Your Path to Error Log should be visible:

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Answer 9

Try to locate your mysql (or mariadb) log folder by this command:

locate local.err 

Answer 10

The approved answer from Bruno didn't work for me on MacOS Monterey, and in any case, it won't help you if your problem is that there is no mysqld process because it failed during startup.

However, following some of the others here enabled me to find the error log:

$ ls -l /usr/local/mysql lrwxr-xr-x 1 root wheel 26 18 Jul 13:39 /usr/local/mysql -> mysql-8.0.29-macos12-arm64 $ sudo ls -l /usr/local/mysql-8.0.29-macos12-arm64/data|grep err -rw-r----- 1 _mysql _mysql 3308 18 Jul 15:01 mysqld.local.err 

Answer 11

/Library/Logs/MySQL.log