Keydb_eng [portable] Here
Blocking commands require careful cross-thread signaling. KeyDB uses a global waiting queue protected by a separate mutex. When data arrives (e.g., LPUSH on a list), the notifying thread checks the waiting queue and wakes the appropriate worker thread, which then resumes the blocked client.
1. Introduction KeyDB is a fork of Redis (starting from Redis 5.0) that maintains full protocol compatibility while introducing a fundamentally different execution engine. Its primary differentiator is multi-threaded processing of queries, allowing it to scale linearly with CPU cores on modern hardware — something that vanilla Redis, by design, cannot do. keydb_eng
For engineering teams bottlenecked by Redis’s single-threaded ceiling, KeyDB offers a pragmatic, drop-in upgrade path. However, it is not a universal replacement; understanding its locking model and command atomicity guarantees is essential for correct use. Blocking commands require careful cross-thread signaling
| Workload | Redis 6 (single-thread) | KeyDB (8 workers) | Gain | |----------|------------------------|-------------------|------| | 100% GET | ~450k ops/sec | ~2.8M ops/sec | 6.2x | | 80% GET, 20% SET | ~380k ops/sec | ~2.1M ops/sec | 5.5x | | 100% SET | ~400k ops/sec | ~1.9M ops/sec | 4.75x | // exclusive lock setKey(c->
As of 2025, KeyDB remains a niche but powerful tool — especially in cloud environments where CPU cores are plentiful and predictable low-latency under concurrency matters more than strict serializability. Would you like a deeper analysis of KeyDB’s active-replica architecture or its memory allocator modifications?
int setCommand(client *c) unique_lock(server.dict_lock); // exclusive lock setKey(c->db, key, val); unique_unlock(server.dict_lock);
