This article breaks down Kafka’s message delivery guarantees—at‑most‑once, at‑least‑once, and exactly‑once—explaining the underlying producer, broker, and consumer requirements, configuration settings, and practical code snippets to achieve reliable delivery.
This article provides a comprehensive guide to KafkaConsumer, covering message delivery semantics (at‑most‑once, at‑least‑once, exactly‑once), practical exactly‑once implementations, consumer rebalance triggers and strategies, partition assignment algorithms, thread‑safety considerations, and detailed Java code examples of the consumer workflow.
The article introduces the Unified Messaging Center (UMC), a comprehensive enterprise message management system that supports multiple channels such as app push, TPNS, SMS, email, WeChat, and DingTalk, detailing each channel's features, usage scenarios, and integration considerations.
Meituan’s Pike 2.0 replaces the Shark‑dependent Pike 1.0 with a four‑layer, TunnelKit‑based bidirectional messaging service that offers shared or independent channels, heartbeat‑driven keep‑alive, aggregated high‑QPS delivery, ordering guarantees, extensive monitoring, and plans for IoT and QUIC enhancements, achieving over 5 billion daily messages with sub‑220 ms latency.
This article explains how to achieve guaranteed 100% message delivery in RabbitMQ by leveraging its acknowledgment mechanisms, implementing producer‑side confirmation steps, designing compensation and retry logic, and ensuring consumer‑side idempotency through unique identifiers and various ID‑generation strategies.
This article explains how network unreliability makes message delivery in distributed systems complex, covering network request outcomes, timeout handling, the three delivery semantics—at‑most‑once, at‑least‑once, exactly‑once—and how protocols like AMQP and MQTT address these challenges.
The article explains how messages travel in monolithic and distributed systems, why network communication is inherently unreliable, and how different delivery semantics—at‑most‑once, at‑least‑once, and exactly‑once—affect reliability, ordering, and protocol choices such as AMQP and MQTT.
The article explains how unreliable network communication in distributed systems leads to three message delivery semantics—at‑most‑once, at‑least‑once, and exactly‑once—detailing their mechanisms, ordering challenges, and common protocols such as AMQP and MQTT.
This article explains how web instant‑messaging systems achieve reliable, non‑lost and non‑duplicate message delivery by using a six‑message protocol (msg R/A/N and ack R/A/N), timeout‑based retransmission, and deduplication mechanisms.
