RabbitMQ is a messaging platform installed alongside Coveo Enterprise Search (CES). It runs as a Windows service named
RabbitMQ for Coveo. Whenever the Coveo Search Provider receives item-related events from Sitecore (created, modified, deleted, etc.), it pushes the corresponding items to RabbitMQ. Then, the Queue Crawler, which runs on the CES side, consumes the items stored in RabbitMQ and pushes them to the Coveo index.
Generally, an administrator will need to administer RabbitMQ for troubleshooting purposes. The current section covers these related articles: