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Introduction

seqdelay is a high-performance delay queue for Go, powered by seqflow's time wheel engine and backed by Redis for persistence and distributed coordination.

Why seqdelay​

Existing delay queue solutions (like ouqiang/delay-queue) poll Redis Sorted Sets every second. This limits precision to ~1s and puts constant load on Redis.

seqdelay uses an in-memory time wheel for scheduling (O(1) add/fire, configurable 1ms precision) and Redis only for persistence and coordination. The result: microsecond precision, millions of tasks per second, and minimal Redis load.

Two Modes​

  • Embedded — import as a Go library, register callbacks, zero network overhead
  • HTTP Server — deploy as a standalone service, any language can interact via HTTP

Key Features​

  • Configurable precision (100us ~ 1s, default 1ms)
  • Redis persistence (Standalone / Sentinel / Cluster)
  • Distributed lock for multi-instance deployment
  • Atomic state transitions via Lua scripts
  • Full recovery from Redis on restart
  • 4.4M tasks/sec scheduling throughput