tower-rs/tower
Tower
Tower is a modular service abstraction layer for the Rust programming language, providing a framework for building asynchronous request-response pipelines. It serves as a set of core components for managing backpressure, balancing loads, and abstracting service discovery.
The project distinguishes itself through a layer-based middleware composition model, allowing services to be wrapped in recursive chains of decorators. This enables the declarative application of cross-cutting concerns, such as timeouts, rate limiting, and retries, in a protocol-agnostic manner.
The library covers a broad range of traffic management and reliability capabilities. It includes tools for load balancing across multiple backend services, request stream buffering to decouple production speed from processing capacity, and load shedding to prevent service exhaustion. Additionally, it provides utilities for request filtering, routing, and the implementation of hedged requests to reduce tail latency.
Features
- Middleware Composition Layers - Provides a modular framework for wrapping services in recursive chains of decorators to apply cross-cutting concerns.
- Service Abstractions - Offers a modular abstraction layer in Rust for building reusable request-response middleware and service wrappers.
- Load Balancers - Provides tools to distribute incoming network requests across multiple backend services to optimize resource utilization.
- Asynchronous Middleware Engines - Provides a set of components for composing timeouts, rate limiting, and retries into a declarative asynchronous pipeline.
- Backpressure Coordination - Coordinates service capacity to manage backpressure and prevent overload by checking availability before dispatching requests.
- Asynchronous Request Handlers - Models the flow of requests and responses using a generic interface for asynchronous communication.
- Future-Based Concurrency Frameworks - Utilizes non-blocking polling of future values to handle concurrent requests without locking execution threads.
- Load Shedding - Implements load shedding to immediately drop excess requests and protect the system from exhaustion under heavy load.
- Request-Response Exchanges - Defines a generic interface for processing asynchronous requests and returning future responses or errors.
- Request Rate Limiting - Caps the number of concurrent or total requests allowed to proceed to inner services to prevent overload.
- Trait-Based Service Abstractions - Defines a generic trait-based interface for mapping requests to future responses, allowing diverse logic to be treated as a single type.
- Custom Middleware Development - Enables the development of reusable, protocol-agnostic components to wrap services with shared behaviors.
- Middleware - Implements a set of shared, protocol-agnostic middleware components for extending asynchronous service functionality.
- Request Retries - Automatically resends requests that encounter errors or exceed latency thresholds to improve system reliability.
- Load Shedding Systems - Implements systems for buffering request streams and shedding excess load to prevent service exhaustion.
- Request Timeout Management - Terminates requests that do not complete within a specified timeframe to prevent resource exhaustion.
- Dynamic Service Discovery - Provides mechanisms for dynamically identifying and routing requests to available network endpoints.
- Request Routing - Steers specific requests to different backend services based on defined criteria.
- Network Reliability - Implements retries, timeouts, and automatic reconnection logic to maintain uptime and reduce tail latency.
- Service Discovery - Provides a mechanism for locating network endpoints and routing traffic dynamically to available backend services.
- Load Balancing Architectures - Implements strategies to distribute requests across a pool of backend endpoints to optimize resource utilization.
- Request Hedging - Implements request hedging by sending redundant requests to alternative services to reduce tail latency.
- Request Timeouts - Monitors asynchronous operation durations and forces error responses if specified time limits are exceeded.
- Request Flow Control - Manages system stability by filtering requests, capping concurrency, and shedding load when services are overwhelmed.
- Asynchronous Request Buffering - Decouples producers from consumers by queuing requests in asynchronous channels to manage processing speed.
- Language Toolkits - Modular components for building robust network services.
