at-least-once | BestHub

Tencent Cloud Developer

Feb 8, 2023 · Backend Development

Design and Implementation of QQ Reminder Subscription Push System

Tencent’s QQ reminder subscription push system combines push‑pull prefetching, heterogeneous MySQL/Redis storage, delayed‑queue triggers, Redis‑based rate‑limiting, task scattering, message‑queue decoupling, at‑least‑once delivery, and dual‑replica disaster recovery within a dispatcher‑worker architecture to ensure reliable, controllable, low‑latency mass notifications.

Message QueuePush NotificationQQ

0 likes · 13 min read

Design and Implementation of QQ Reminder Subscription Push System

IT Architects Alliance

Aug 29, 2021 · Big Data

Kafka Storage Mechanism and Reliability Guarantees

This article explains Kafka's storage architecture—including topics, partitions, segments, and their naming rules—along with how data is read, and details the system's reliability features such as ISR/OSR replication, leader election, producer acknowledgment levels, and delivery guarantees.

KafkaLeader ElectionReliability

0 likes · 10 min read

Kafka Storage Mechanism and Reliability Guarantees

Youzan Coder

Mar 1, 2019 · Big Data

Flume Practice at YouZan: Data Collection and Pipeline Construction in Big Data Scenarios

YouZan’s experience with Flume shows how the at‑least‑once delivery model, combined with FileChannel storage and custom extensions such as an NsqSource, hourly‑based HdfsEventSink, metric reporting server, and timestamp interceptor, can reliably move MySQL binlog data to HDFS, while tuning transaction batch size and channel capacity boosts throughput and stability, paving the way for a unified management platform.

Big DataHDFSNSQ

0 likes · 11 min read

Flume Practice at YouZan: Data Collection and Pipeline Construction in Big Data Scenarios

Architecture Digest

Sep 4, 2018 · Fundamentals

Message Delivery Semantics in Distributed Systems: At-Most-Once, At-Least-Once, and Exactly-Once

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.

Message Deliveryat-least-oncedistributed systems

0 likes · 14 min read

Message Delivery Semantics in Distributed Systems: At-Most-Once, At-Least-Once, and Exactly-Once