Troubleshooting

This section provides some hints to solve the most common replication errors.

A slave does not start

When we execute START SLAVE, we do not receive any error if the slave cannot connect to a master. By executing SHOW SLAVE STATUS we will know what the I/O thread is doing.

If the replication does not start, or if it crashes, we will need to find out the reason and solve the problem. The following list of question can be used to find out the most common trivial problems:

• Is the slave version equal to or minor than the master version?
• Is the binary log enabled on the master?
• Are the server IDs unique?
• Is a variable name mistyped in the configuration file? Can the file be used to successfully start a standalone server?
• Are the master's address, port, and login credentials correctly configured in the slave?
• Is an account for the slave configured in the server?
• Does the account have the REPLICATION SLAVE permission?
• Is there a firewall that blocks the slave connections?
• Are the replication...