Skip to main content

​
MySQL FAQ

Common questions and answers about using MySQL with RocketPlaceholders.

​
General Questions

​
What is the difference from MySQL and YML?

YML (Local Storage):
  • Placeholders stored in local files
  • Only available on the server where they’re created
  • No synchronization between servers
MySQL:
  • Placeholders stored in a database
  • Synchronized across all connected servers
  • Centralized management from one main server
Use MySQL if you have multiple servers and want to manage placeholders centrally. Use YML for single-server setups or when you don’t need synchronization.

​
What is a Main Server?

The main server is the server that stores placeholders in the MySQL database. All other servers read placeholders from the database.
Only one server can be the main server. If multiple servers have main: true, it can cause conflicts.
How it works:
  1. Main server writes placeholders to the database
  2. Other servers read placeholders from the database
  3. Changes on the main server automatically sync to other servers

​
Will the MySQL cause lag?

No, MySQL synchronization is optimized and won’t cause noticeable lag. All database operations are performed asynchronously, meaning they don’t block the main server thread.
RocketPlaceholders uses efficient database queries and connection pooling to minimize any performance impact.

​
Configuration Questions

​
If I use MySQL, are the config’s placeholders read?

Yes! If the server is not a main server, you’ll have:
  • Placeholders from the MySQL database (from the main server)
  • Placeholders from the local config file
Priority:
  1. Database placeholders (from main server)
  2. Local config placeholders
Database placeholders take priority over local placeholders.

​
How can I delete all my config’s placeholders to use only database placeholders?

Simply delete all placeholders from your local placeholders folder: 
placeholders:
  # Nothing here ツ
This ensures only database placeholders are used.

​
Can I have different placeholders on different servers?

Yes, but with limitations:
  • Main server: Manages database placeholders (shared across all servers)
  • Other servers: Can have local placeholders in addition to database placeholders
  • Local placeholders on non-main servers won’t sync to other servers
Example Setup:
  • Main server: Has database placeholders (shared)
  • Server 1: Has database placeholders + local server-specific placeholders
  • Server 2: Has database placeholders + different local server-specific placeholders

​
Troubleshooting

​
Placeholders aren’t syncing between servers

Check:
  1. MySQL is enabled on all servers (enabled: true)
  2. Only one server has main: true
  3. All servers are connected to the same database
  4. Database connection information is correct on all servers
  5. Servers have restarted after configuration changes

​
Changes on non-main server aren’t appearing

Remember:
  • Only changes on the main server sync to the database
  • Changes on other servers are local only
  • Make all placeholder changes on the main server

​
Can’t connect to MySQL

Check:
  • MySQL server is running
  • IP address and port are correct
  • Username and password are correct
  • Database exists
  • Firewall allows connections
  • MySQL user has CREATE, SELECT, INSERT, UPDATE, DELETE permissions

​
Database connection errors

Common issues:
  • Incorrect credentials
  • Database doesn’t exist
  • MySQL server not running
  • Network/firewall blocking connection
  • MySQL user lacks permissions

​
Best Practices

​
1. Backup Regularly

Always backup your MySQL database containing placeholders: 
mysqldump -u root -p rocketplaceholders > backup.sql

​
2. One Main Server

Always have exactly one server set as main. Having zero or multiple main servers can cause issues.

​
3. Test Changes

Test placeholder changes on the main server before expecting them on other servers.

​
4. Monitor Connections

Keep an eye on MySQL connection logs to ensure all servers are connecting properly.