Comment by kerblang
8 days ago
Kafka is really not intended to improve on this. Instead, it's intended for very high-volume ETL processing, where a classical message queue delivering records would spend too much time on locking. Kafka is hot-rodding the message queue design and removing guard rails to get more messages thru faster.
Generally I say, "Message queues are for tasks, Kafka is for data." But in the latter case, if your data volume is not huge, a message queue for async ETL will do just fine and give better guarantees as FIFO goes.
In essence, Kafka is a very specialized version of much more general-purpose message queues, which should be your default starting point. It's similar to replacing a SQL RDBMS with some kind of special NoSQL system - if you need it, okay, but otherwise the general-purpose default is usually the better option.
Of course this is not the same as Kafka, but the comment I'm replying to:
Seemed to imply that it's not possible to build a high performance pub/sub system using a simple SQL select. I do not think that is true and it is in fact fairly easy to build a high performance pub/sub system with a simple SQL select. Clearly, this design as proposed is not the same as Kafka.
No, I implied that implementing pub/sub with just a select statement is silly because it is. Your implementation accounts for the downfalls of this approach with smart design using a message queue and intelligent locking semantics. Parent of my comment was glib and included none of this.