Messenger

A messenger hook allows the plugin to synchronize data between hosts that are using the same external database.

Not setting a messenger instance may lead to data loss.

This concept also uses a main channel to transfer messages, every server with a messenger instance must use the same channel name.

PixelBuy currently supports SQL, REDIS and RABBITMQ messenger types, set AUTO to let the plugin choose the best available option.

Sql

The SQL messenger type uses the current sql database to transfer messages by adding rows into a separated table, then checks for any unread row (probably added by another plugin instance on a different host).

Every 30 seconds, all rows more than 60 seconds old are automatically deleted by every plugin instance connected at the same SQL messenger instance.

Redis

The REDIS messenger type connects to a Redis instance to transfer messages, there's not much to say since it's a highly known system.

RabbitMQ

The RABBITMQ messenger type connects to a RabbitMQ instance to transfer temporary messages, instead of Redis this type of messaging is more standardized (and probably better), additionally it requires to set an exchange or "pre-channel" to access messenger channels.