Design of a Distributed Messaging Queue: Part 2
Examine how backend services manage message storage and replication in a distributed messaging queue. Compare the primary-secondary model with a cluster of independent brokers. Explain how internal and external cluster managers coordinate queue placement, membership, and failover to maintain high availability.
We'll cover the following...
Previously, we discussed frontend servers and metadata services. This lesson focuses on the backend service that stores queues and messages.
Backend service
The backend service handles message storage, routing, and replication. When the frontend receives a message, it queries the metadata service to determine which broker is responsible for the queue. The message is forwarded to that broker and replicated to other nodes in the cluster to improve availability and durability. Replication typically follows one of two models: