After writing about the Disruptor’s design, the obvious question is: how much faster is it, really? “Faster” is not a useful answer. Let’s look at actual numbers under controlled conditions. This is a benchmarking exercise, not a recommendation. The right data structure depends on your use case. The goal here is to understand the performance characteristics of each under different contention patterns. ...
In mid-2013 we replaced our internal LinkedBlockingQueue-based event bus with the LMAX Disruptor. Median latency dropped by 30%. The 99th percentile dropped by more than half. The change touched about 400 lines of code. This post is about the conceptual model you need to understand why the Disruptor is fast — not just “it uses a ring buffer,” but what that actually means for your hardware. ...
Locks work. synchronized in Java is correct, well-understood, and wrong for our use case. A lock that’s contested causes a thread to block — the OS parks it, context-switches to something else, and eventually context-switches back. Each of those transitions costs microseconds. When your SLA is sub-millisecond and your hot path is called 200,000 times per second, locks are not an option. Lock-free programming replaces locks with atomic CPU instructions. The CPU handles the synchronisation at the hardware level, without OS involvement. ...