Q. I get a large amount of bin files in the MySQL data directory called “server-bin.n” or mysql-bin.00000n, where n is a number that increments. What is MySQL Binary Log? How do I stop these files being created?
A. Usually /var/lib/mysql stores the binary log files. The binary log contains all statements that update data or potentially could have updated it. For example, a DELETE or UPDATE which matched no rows. Statements are stored in the form of events that describe the modifications. The binary log also contains information about how long each statement took that updated data.
The purpose of MySQL Binary Log
The binary log has two important purposes:
- Data Recovery : It may be used for data recovery operations. After a backup file has been restored, the events in the binary log that were recorded after the backup was made are re-executed. These events bring databases up to date from the point of the backup.
- High availability / replication : The binary log is used on master replication servers as a record of the statements to be sent to slave servers. The master server sends the events contained in its binary log to its slaves, which execute those events to make the same data changes that were made on the master.
Disable MySQL binlogging
If you are not replicating, you can disable binlogging by changing your my.ini or my.cnf file. Open your my.ini or /etc/my.cnf (/etc/mysql/my.cnf), enter:
# vi /etc/my.cnf
Find a line that reads “log_bin” and remove or comment it as follows:
#log_bin = /var/log/mysql/mysql-bin.log
You also need to remove or comment following lines:
#expire_logs_days = 10 #max_binlog_size = 100M
Close and save the file. Finally, restart mysql server:
# service mysql restart
Purge Master Logs
If you ARE replicating, then you need to periodically RESET MASTER or PURGE MASTER LOGS to clear out the old logs as those files are necessary for the proper operation of replication. Use following command to purge master logs:
$ mysql -u root -p 'MyPassword' -e "PURGE BINARY LOGS TO 'mysql-bin.03';"
OR
$ mysql -u root -p 'MyPassword' -e "PURGE BINARY LOGS BEFORE '2008-12-15 10:06:06';"
Suggested readings:
MySQL Manual – The binary logs
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If you are using
expire_logs_days = 10
max_binlog_size = 100M
You will not need to do purge logs manually .. logs older than 10 days will be purged automatically by mysql server …
Thanks
Amr Hamdy,
you’re right but if you disable log_bin, you must purge manually.
Thanks for this post.
Hi, thanks for the tips
does it works on innodb too ?
Awesome tip. My logs were taking up 40 Gigs on my dev server and I had no idea.
Thanks!
#!/bin/bashCURRENT_LOGFILE=$(/usr/bin/mysql -u root -p -S -e "SHOW SLAVE STATUS\G" | awk '$1 == "Master_Log_File:" {print $2}')
echo "Purging Master Logs before ${CURRENT_LOGFILE}"
/usr/bin/mysql -uroot -p -h -P -e "PURGE MASTER LOGS TO '${CURRENT_LOGFILE}'"
echo "Purging Slave Logs before Current Log'"
/usr/bin/mysql -uroot -p -h -S -e "purge binary logs before now();"
exit $?
Hi, just a small correction:
About the High availability / replication section. It states that the Master sends the binary logs to the slave. However, it’s actually the slave that pulls the log/data from the master.
“Each slave that connects to the master requests a copy of the binary log. That is, it pulls the data from the master, rather than the master pushing the data to the slave”
Source: http://dev.mysql.com/doc/refman/5.0/en/replication-implementation.html
hi
could you tell me how to perform the data recovery operations by these files
thanks
Alternatively, you can try this mysql> PURGE BINARY LOGS BEFORE DATE_SUB( NOW( ), INTERVAL 7 DAY);
This deletes all logs older than 7 days.
Alternatively we can simply use this command
mysql> PURGE BINARY LOGS BEFORE DATE_SUB( NOW( ), INTERVAL 7 DAY);
It deletes all old logs older than 7 days.
nice information ….
PURGE BINARY LOGS BEFORE now()
Hi Friends, is it possiable to setup a master, slave replication without binlog process… any idea pls… give me asap.
Set up replication…without the logs it uses for replication to happen? No. If the master doesn’t log, there is nothing for the slave to download and apply.
great article, thanks!