MySQL init failure on every server start

[TheNathanSpace]

Question

When I try to run Plan with a MySQL server, I get an error. It successfully downloads Plan/libraries/mysql-mysql-connector-java-8.0.27.jar, but gives this error:

[03:28:16 INFO]: [Plan] Enabling Plan v5.4 build 1516
[03:28:17 INFO]: [Plan]
[03:28:17 INFO]: [Plan]            ██▌
[03:28:17 INFO]: [Plan]      ██▌   ██▌
[03:28:17 INFO]: [Plan]   ██▌██▌██▌██▌  Player Analytics
[03:28:17 INFO]: [Plan]   ██▌██▌██▌██▌  v5.4 build 1516
[03:28:17 INFO]: [Plan]
[03:28:17 INFO]: [Plan] Locale: 'English' by AuroraLS3
[03:28:17 INFO]: [Plan] Downloading MySQL Driver, this may take a while...
[03:28:48 ERROR]: [Plan] ----------------------------------------
[03:28:48 ERROR]: [Plan] Error: MySQL init failure: Failed to initialize pool: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
[03:28:48 ERROR]: [Plan] ----------------------------------------
[03:28:48 ERROR]: [Plan] Plugin Failed to Initialize Correctly. If this issue is caused by config settings you can use /plan reload

Additional context

This is Plan 5.4 Build 1516. Here's what my config looks like:

Config:

# -----------------------------------------------------
# Supported databases: SQLite, MySQL
# -----------------------------------------------------
Database:
    Type: MySQL
    MySQL:
        Host: IP ADDRESS
        Port: 3306
        User: USERNAME
        Password: PASSWORD
        Database: DB NAME
        # Launch options to append after mysql driver address
        Launch_options: "?rewriteBatchedStatements=true&useSSL=false&serverTimezone=UTC"
        Max_connections: 8

The MySQL server is running. The database does exist, but this error shows up every time I start the server. Does anybody know what I'm doing wrong here?

[AuroraLS3]

The IP if the database could be wrong, or the port MySQL is using is closed (if the db is on different machine or if using the public ip)

If you're using pterodactyl see their MySQL tutorial

[TheNathanSpace]

Well, I deleted and recreated the Plan database, and then I had some permission errors, so after granting the permissions it looks like MySQL is working fine. Strange—thanks!