vitess.io/messages (go): Package messages defines a pubsub style of interfacing with the Vitess Messaging feature. The goal is to provide a simple and performant way to use message queues without needing to worry about the underlying SQL and system architecture. All operations are safe for concurrent use.  More details can be found at http://vitess.io/advanced/messaging/  Queues are the core component of messaging, and require the MySQL tables to be set up before they can be used. They are treated like any other table in terms of vschema and sharding. The definition requires strict field ordering for required fields, followed by N payload fields. There is no restriction on the payload field types.  Perhaps the most valuable feature of Vitess messages is that you can atomically add, ack or fail messages in the same transaction as your actual data commits. The Execer interface lets you optionally provide a sql.DB / sql.Tx that these commands will be executed on. There is no requirement that these need to use the Vitess driver. You can perform any of these operations without needing to run Queue.Open.  This utilizes some custom Vitess syntax and connection parameters, so the queue itself creates a sql.DB that it uses under the hood to stream messages. The max concurrency definition determines how many messages will be leased out and kept in memory at any given time. No connection is made until Queue.Open is run.
Keywords: message-queue|mysql|queue|task-queue|vitess