Error
Error Code:
1595
MariaDB Error 1595: Relay Log Write Failure
Description
Error 1595 indicates that a MariaDB slave server encountered a problem writing events to its relay logs. Relay logs are essential for replication, storing transactions received from the master before they are processed and applied to the slave's database. This failure halts replication and prevents the slave from catching up with the master.
Error Message
Relay log write failure: %s
Known Causes
3 known causesInsufficient Disk Space
The slave server's disk where relay logs are stored has run out of free space, preventing new log entries from being written.
Incorrect File Permissions
The MariaDB process lacks the necessary write permissions for the directory intended to store the relay log files.
Disk I/O or File System Issues
Underlying hardware problems or file system corruption on the slave server can prevent successful writes to the relay log.
Solutions
4 solutions available1. Check Disk Space and I/O Performance easy
Ensures the disk holding the relay logs has sufficient space and is not experiencing I/O bottlenecks.
1
Verify available disk space on the partition where your MariaDB relay logs are located. Use 'df -h' command.
df -h2
If disk space is low, clear unnecessary files or expand the partition. Consider moving the relay log directory to a partition with more space.
3
Monitor disk I/O performance. High I/O wait times can indicate a bottleneck. Use tools like 'iostat' or system monitoring software.
iostat -xz 14
If I/O is a bottleneck, consider migrating the relay log directory to faster storage (e.g., SSDs) or optimizing other processes consuming disk I/O.
2. Restart MariaDB Service easy
A simple restart can often resolve transient issues with file handles or internal processes.
1
Gracefully stop the MariaDB service. The command may vary depending on your operating system and installation method.
sudo systemctl stop mariadb2
Wait for the service to fully stop. Check the status to confirm.
sudo systemctl status mariadb3
Start the MariaDB service.
sudo systemctl start mariadb4
Check the MariaDB error log for any new errors after the restart.
3. Reconfigure Relay Log Settings medium
Adjusting relay log parameters or ensuring they are correctly configured can resolve write issues.
1
Locate your MariaDB configuration file (e.g., my.cnf, mariadb.conf.d/50-server.cnf).
2
Check the `relay_log` and `log_bin` settings in the `[mysqld]` section. Ensure `log_bin` is enabled if you are using replication or binary logs.
[mysqld]
log_bin = /var/lib/mysql/mysql-bin
relay_log = /var/lib/mysql/mysql-relay-bin3
Verify that the directory specified for `relay_log` exists and that the MariaDB user has write permissions to it.
ls -ld /var/lib/mysql/
chown -R mysql:mysql /var/lib/mysql/4
Consider temporarily disabling `sync_relay_log` for testing purposes if I/O is suspected, but be aware of the implications for data durability.
[mysqld]
sync_relay_log = 05
Restart MariaDB after making any configuration changes.
sudo systemctl restart mariadb4. Inspect and Clear Corrupted Relay Logs advanced
If relay logs are corrupted, they can prevent new writes. This involves identifying and potentially clearing them.
1
Stop the MariaDB service to prevent further writes to the relay logs.
sudo systemctl stop mariadb2
Navigate to the directory where your relay logs are stored (specified by `relay_log` in your configuration).
cd /var/lib/mysql/3
Identify the current relay log files (e.g., `mysql-relay-bin.xxxxxx` and `mysql-relay-bin.index`).
ls -l mysql-relay-bin*4
If you suspect corruption and have a recent backup or are certain you can afford to lose replication state, you can rename or delete the current relay log files. **WARNING: This will break replication if this is a replica server.**
mv mysql-relay-bin.xxxxxx mysql-relay-bin.xxxxxx.bak
mv mysql-relay-bin.index mysql-relay-bin.index.bak5
Start MariaDB. It should create new relay log files.
sudo systemctl start mariadb6
If this is a replica server, you will need to re-establish replication from the master using `CHANGE MASTER TO` command and potentially re-sync data.