Timestone: Netflix’s High-Throughput, Low-Latency Priority Queueing System with Built-in Support for Non-Parallelizable Workloads

Timestone: Netflix’ s High-Throughput, Low-Latency Priority Queueing System with Built-in Support for Non-Parallelizable Workloads

摘要

Timestone is a high-throughput, low-latency priority queueing system we built in-house to support the needs of our media encoding platform, Cosmos. Over the past 2.5 years, its usage has increased, and Timestone is now also the priority queueing engine backing our general-purpose workflow orchestration engine (Conductor), and the scheduler for large-scale data pipelines (BDP Scheduler). All in all, millions of critical workflows within Netflix now flow through Timestone on a daily basis.

Timestone clients can create queues, enqueue messages with user-defined deadlines and metadata, then dequeue these messages in an earliest-deadline-first (EDF) fashion. Filtering for EDF messages with criteria (e.g. “messages that belong to queue X and have metadata Y”) is also supported.

One of the things that make Timestone different from other priority queues is its support for a construct we call exclusive queues — this is a means to mark chunks of work as non-parallelizable, without requiring any locking or coordination on the consumer side; everything is taken care of by the exclusive queue in the background. We explain the concept in detail in the sections that follow.