What is Rapira?

Rapira is a PHP application server written in Rust.

The RoadRunner maintainers design and implement Rapira. Rapira calls PHP directly in the server process.

Rapira supports HTTP and gRPC. Each protocol has its own listener and PHP worker pool.

The blog contains project updates.

HTTP

Rapira includes an HTTP server that uses the hyper library. It accepts plain HTTP/1.1 and HTTP/1.0 connections. Rapira does not terminate TLS. A TLS termination proxy accepts HTTPS from a client, decrypts the connection, and sends plain HTTP to Rapira. See Running in production for proxy configuration.

Rapira supports three PHP execution modes:

• Classic: Rapira initializes the application for each request, as php-fpm does.
• Worker: Rapira initializes the application once. A loop handles requests, and Rapira refills PHP superglobals for each request.
• Dispatcher: Rapira initializes the application once. The script gets request objects through an API call. Each worker handles one request at a time.

See Execution modes for mode behavior and selection criteria.

gRPC

Rapira serves unary gRPC, gRPC-Web, and Connect calls on one listener. The PHP application receives and returns binary protobuf messages through a dispatcher. The master loads the service schemas from a descriptor set before the workers start.

The gRPC pool uses Dispatcher mode. HTTP and gRPC can run together with separate entrypoints. See gRPC for a complete service, protobuf class generation, and client commands.

Metrics and health checks

An optional [observability] table starts one more process that does not run PHP. The [observability.metrics] sub-table turns on Prometheus metrics at /metrics. The [observability.probes] sub-table turns on the /livez and /readyz probes. See Metrics and health checks for the configuration and the endpoints.