How Netflix Content Engineering makes a federated graph searchable

Netflix Technology Blog
11 min readintermediate
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Overview

The article discusses how Netflix's Content Engineering team has transitioned to a federated GraphQL platform, enabling domain teams to build and operate their own Domain Graph Services (DGS). It highlights the creation of the Studio Search platform, which allows for efficient querying of a federated graph, and details the architecture and technologies used to maintain an up-to-date index of the graph's entities.

What You'll Learn

1

How to implement a federated GraphQL architecture for scalable services

2

Why using Elasticsearch is beneficial for indexing federated graph data

3

How to maintain index consistency in a federated architecture

4

When to use Change Data Capture (CDC) for real-time indexing

Prerequisites & Requirements

  • Understanding of GraphQL and its federation capabilities
  • Familiarity with Elasticsearch and its indexing mechanisms(optional)
  • Experience with microservices architecture

Key Questions Answered

How does Netflix make a federated graph searchable?
Netflix employs a Studio Search platform that indexes a portion of the federated graph, allowing users to query entities based on text input and relationships. The platform uses Elasticsearch to maintain an up-to-date index that reflects changes in the graph's entities in near real-time.
What technologies are used in Netflix's indexing pipeline?
The indexing pipeline utilizes Elasticsearch for indexing, GraphQL for querying the federated graph, and Change Data Capture (CDC) events to keep the index updated. This combination allows for efficient querying and real-time data synchronization.
What challenges does Netflix face with index consistency?
As the index grows complex and depends on multiple Domain Graph Services (DGSes), errors can occur when fetching documents, leading to outdated or missing entries. This necessitates manual follow-ups with domain teams to resolve issues and replay failed events.
How does Netflix handle reverse lookups in its indexing process?
Reverse lookups are implemented to maintain index accuracy when related entities change. When a change occurs, the system queries the index for all primary entities that could be affected, ensuring that the index remains consistent and up-to-date.

Technologies & Tools

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Key Actionable Insights

1
Implementing a federated GraphQL architecture can significantly enhance team autonomy and service scalability.
By allowing domain teams to independently manage their services, organizations can reduce bottlenecks and improve deployment speed, making it easier to adapt to changing business needs.
2
Utilizing Change Data Capture (CDC) events is crucial for maintaining real-time index updates.
CDC enables the system to react promptly to changes in data, ensuring that the index reflects the most current state of the federated graph, which is essential for accurate querying.
3
Automating the configuration collection process simplifies the user experience for engineers.
By providing a single configuration file, teams can easily define their indexing pipelines without getting bogged down in manual setup, leading to faster implementation times.

Common Pitfalls

1
Manual configuration of indexing pipelines can lead to errors and inefficiencies.
Without automation, engineers may struggle with the complexity of configurations, leading to delays and potential mistakes in the setup process.
2
Reverse lookups can create circular dependencies that complicate the indexing pipeline.
This complexity requires a deep understanding of the eventing system, which can be a barrier for teams unfamiliar with the interconnected nature of the data.

Related Concepts

Graphql Federation
Change Data Capture (cdc)
Microservices Architecture
Data Mesh