InvSync

With this mod you can sync your inventory and the tablist between different servers. That means if you leave one server and join to another server, your inventory will be the same. Also you can see which players are active on another linked server without even visiting it.

For server owners:

This mod is required on all of the servers you want to synchronize. In addition you also need a MySQL / MariaDB server and a free database (the name does not matter). JCLib, the connector core of this mod will now do most of the work for you. Simply set all of the important values in it's config file (e.g. .minecraft/config/jclib-common.toml) and you're ready to go. Already with the next startup, all servers which share a database will be linked. As a consequence - even without users having the mod installed - the inventories will be synchronized between all of your servers. If you also want to use the synced tablist feature, it's mandatory to also install the mod on the client-side.

How it works:

1. The synced inventories: Once your server successfully connected to the database, it won't do anything by default. Only if a player joins it will then read back the stored inventory from the DB, overriding the server's own player inventory. Furthermore, every 5 minutes the server will then upload every player's current inventory state to the database. This process prevents potential dataloss caused by a server-crash. Once a player then leaves the particular server, his inventory is uploaded a last time to the database allowing all other linked servers to download the current invenstory state.