Queues

Command/Document/Event message types; one-way/req-resp/broadcast styles; Request-Reply (sync block vs async callback; Return Address; Correlation Identifier); point-to-point/pub-sub/datatype channels; Pub-Sub as distributed Observer (push vs pull; channel design); at-least-once delivery; guaranteed delivery; exactly-once via idempotency; invalid vs dead letter channel; backlogs; poison message isolation; competing consumers; data safety trade-off (publisher confirms + persistent queues + manual ACKs); quorum queues (RAFT); RabbitMQ internals; Pipes and Filters; Message Router; Message Bus; Messaging Bridge; Aggregator; Resequencer; Composed Message Processor; Scatter-Gather; Routing Slip; Process Manager; Message Broker (architectural pattern); Envelope Wrapper; Content Enricher; Content Filter; Claim Check; Normalizer; Canonical Data Model; Messaging Gateway; Messaging Mapper; Transactional Client; Polling Consumer; Event-Driven Consumer; Competing Consumers; Message Dispatcher; Selective Consumer; Durable Subscriber; Idempotent Receiver; Service Activator; Control Bus; Detour; Wire Tap; Message History; Message Store; Smart Proxy; Test Message; Channel Purger