Plots are no longer claimable after some time - Database Error

Server Implementation

Paper

Server Version

1.21.3 (1.21.3-82-5a60ffb)

Describe the bug

After some time, players are unable to claim plots anymore. Neither /p auto nor /p claim work. In the console, I receive the following message repeatedly: [PlotSquared/Claim] Failed to add plot to database: 12,17. This occurs for every attempted claim. There are no further stack traces in the logs.

However, when shutting down the server, to fix the issue, multiple exceptions appear:

In the meantime, the server freezes and does not shut down, so I have to kill it.

To Reproduce

I'm not sure how exactly to reproduce this issue, as it has only happened about once or twice per month over the last few years. However, today alone it occurred three times on a freshly set up server where many plot commands are being executed. This server was just launched today, and with 100 players actively using it, a lot of plot-related commands are being run.

Expected behaviour

Players should be able to continuously claim plots without issues, and database interactions should function reliably.

Screenshots / Videos

No response

Error log (if applicable)

No response

Plot Debugpaste

I prefer not to include a debugpaste as it may contain sensitive plugin and data information. However, I have discussed this with Pierre, and he has a debugpaste available.

PlotSquared Version

PlotSquared-7.4.1-Premium

Checklist

• I have included a Plot debugpaste.
• I am using the newest build from https://www.spigotmc.org/resources/77506/ and the issue still persists.

Anything else?

• I'm using MySQL as the database backend, mariadb:11
• The database connection is confirmed to be stable, all other actions can still be executed - e.g. adding flags etc. and other servers are also connected to the MySQL Service.

Start with the plot claim database path and the shutdown exceptions shown in the issue, using the reported MariaDB 11 backend and repeated Failed to add plot to database message as the trigger. Reproduce under sustained claim traffic if possible, then verify that claims continue to succeed and the server shuts down cleanly without database exceptions.