Meta Introduces ZGateway Proxy for ZippyDB to Unify Traffic and Improve Management

Introducing ZGateway

Meta has launched ZGateway, a new proxy designed to unify traffic for ZippyDB, the company's most widely used key-value store. ZippyDB supports product metadata, counters, and configuration, handling billions of operations per second across a global fleet. ZGateway acts as an intermediary layer, managing client connections to the database.

Addressing Client Sprawl

The development of ZGateway was driven by the need to manage the extensive and diverse client population of ZippyDB. With over a million client hosts owned by hundreds of teams, making rapid changes across all client binaries was impractical. A proxy provides a centralized point to implement shared functionalities that would otherwise be difficult or impossible to deploy at the client level.

Benefits of a Proxy Layer

ZGateway offers several advantages, including admission control, load balancing, and cross-region resilience. It also centralizes shared work such as connection pooling, retries, and routing, which are now handled by the team managing the backend. This approach allows for quicker changes and better visibility into the overall workload compared to the previous direct-access model where each client connected to every necessary database host.

Structural Advantages

The proxy model bounds the problem by allowing the backend to interact with a controlled fleet rather than a vast client population. It creates a single point of control where the entire workload can be observed, load attributed, and behavior modified rapidly. This contrasts with the direct-access model, which resulted in a dense many-to-many mesh of TLS connections, with individual clients maintaining tens of thousands of connections to database hosts.