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netflix

Netflix Live Origin. Xiaomei Liu, Joseph Lynch, Chris Newton | by Netflix Technology Blog | Dec, 2025 | Netflix TechBlog (opens in new tab)

The Netflix Live Origin is a specialized, multi-tenant microservice designed to bridge the gap between cloud-based live streaming pipelines and the Open Connect content delivery network. By operating as an intelligent broker, it manages content selection across redundant regional pipelines to ensure that only valid, high-quality segments are distributed to client devices. This architecture allows Netflix to achieve high resilience and stream integrity through server-side failover and deterministic segment selection. ### Multi-Pipeline and Multi-Region Awareness * The origin server mitigates common live streaming defects, such as missing segments, timing discontinuities, and short segments containing missing video or audio samples. * It leverages independent, redundant streaming pipelines across different AWS regions to ensure high availability; if one pipeline fails or produces a defective segment, the origin selects a valid candidate from an alternate path. * Implementation of epoch locking at the cloud encoder level allows the origin to interchangeably select segments from various pipelines. * The system uses lightweight media inspection at the packager level to generate metadata, which the origin then uses to perform deterministic candidate selection. ### Stream Distribution and Protocol Integration * The service operates on AWS EC2 instances and utilizes standard HTTP protocol features for communication. * Upstream packagers use HTTP PUT requests to push segments into storage at specific URLs, while the downstream Open Connect network retrieves them via GET requests. * The architecture is optimized for a manifest design that uses segment templates and constant segment durations, which reduces the need for frequent manifest refreshes. ### Open Connect Streaming Optimization * While Netflix’s Open Connect Appliances (OCAs) were originally optimized for VOD, the Live Origin extends nginx proxy-caching functionality to meet live-specific requirements. * OCAs are provided with Live Event Configuration data, including Availability Start Times and initial segment numbers, to determine the legitimate range of segments for an event. * This predictive modeling allows the CDN to reject requests for objects outside the valid range immediately, reducing unnecessary traffic and load on the origin. By decoupling the live streaming pipeline from the distribution network through this specialized origin layer, Netflix can maintain a high level of fault tolerance and stream stability. This approach minimizes client-side complexity by handling failovers and segment selection on the server side, ensuring a seamless experience for viewers of live events.

live-streamingawsmicroservicesnginx+4
netflix

Behind the Streams: Real-Time Recommendations for Live Events Part 3 | by Netflix Technology Blog | Netflix TechBlog (opens in new tab)

Netflix manages the massive surge of concurrent users during live events by utilizing a hybrid strategy of prefetching and real-time broadcasting to deliver synchronized recommendations. By decoupling data delivery from the live trigger, the system avoids the "thundering herd" effect that would otherwise overwhelm cloud infrastructure during record-breaking broadcasts. This architecture ensures that millions of global devices receive timely updates and visual cues without requiring linear, inefficient scaling of compute resources. ### The Constraint Optimization Problem To maintain a seamless experience, Netflix engineers balance three primary technical constraints: time to update, request throughput, and compute cardinality. * **Time:** The specific duration required to coordinate and push a recommendation update to the entire global fleet. * **Throughput:** The maximum capacity of cloud services to handle incoming requests without service degradation. * **Cardinality:** The variety and complexity of unique requests necessary to serve personalized updates to different user segments. ### Two-Phase Recommendation Delivery The system splits the delivery process into two distinct stages to smooth out traffic spikes and ensure high availability. * **Prefetching Phase:** While members browse the app normally before an event, the system downloads materialized recommendations, metadata, and artwork into the device's local cache. * **Broadcasting Phase:** When the event begins, a low-cardinality "at least once" message is broadcast to all connected devices, triggering them to display the already-cached content instantaneously. * **Traffic Smoothing:** This approach eliminates the need for massive, real-time data fetches at the moment of kickoff, distributing the heavy lifting of data transfer over a longer period. ### Live State Management and UI Synchronization A dedicated Live State Management (LSM) system tracks event schedules in real time to ensure the user interface stays perfectly in sync with the production. * **Dynamic Adjustments:** If a live event is delayed or ends early, the LSM adjusts the broadcast triggers to preserve accuracy and prevent "spoilers" or dead links. * **Visual Cues:** The UI utilizes "Live" badging and dynamic artwork transitions to signal urgency and guide users toward the stream. * **Frictionless Playback:** For members already on a title’s detail page, the system can trigger an automatic transition into the live player the moment the broadcast begins, reducing navigation latency. To support global-scale live events, technical teams should prioritize edge-heavy strategies that pre-position assets on client devices. By shifting from a reactive request-response model to a proactive prefetch-and-trigger model, platforms can maintain high performance and reliability even during the most significant traffic peaks.

live-streamingdistributed-systemsrecommendation-systemsscalability+4