HTTP (Hypertext Transfer Protocol) is a protocol used for transmitting hypertext requests and responses on the World Wide Web. It is a request-response protocol, meaning that a client sends a request to a server, and the server responds with the requested data. In the context of software development and distribution, HTTP is commonly used for making requests to REST APIs or other web services.
Overview
HTTP is a fundamental technology for the World Wide Web, and it has been in use since the early days of the web. It is a text-based protocol, which means that all communication between the client and server is in plain text. HTTP messages consist of a request line, headers, and an optional message body.
The http package in Node.js is a popular choice for making HTTP requests in Node.js projects. It provides an easy-to-use interface for making requests to REST APIs or other web services. However, it is important to note that the http package is currently a security holding package, and it is recommended to use other popular HTTP client libraries like axios, node-fetch, or request for making HTTP requests in your projects.
HTTP Protocols
HTTP has several versions, each with its own features and capabilities. The most commonly used versions are HTTP/1.0, HTTP/1.1, and HTTP/2. HTTP/1.0 is the oldest version and is now considered obsolete. HTTP/1.1 introduced several improvements, such as persistent connections and chunked transfer encoding. HTTP/2 is the latest version and offers significant performance improvements, such as binary framing and server push.
HTTP Connection Management
HTTP connection management refers to the process of managing the connections between the client and server during an HTTP transaction. This includes managing the lifecycle of the connection, handling HTTP headers, and managing the flow of data between the client and server.
Envoy is an open-source edge and service proxy designed for both single services and microservice architectures. It includes an HTTP connection manager, which is responsible for managing the HTTP connections and requests. The HTTP connection manager translates raw bytes into HTTP level messages and events, handles functionality common to all HTTP connections and requests, and provides advanced routing capabilities.
HTTP Routing
HTTP routing refers to the process of directing HTTP requests to the appropriate backend service or origin server. HTTP routing can be used for traditional reverse proxy request handling, as well as for building a service-to-service Envoy mesh. Envoy includes an HTTP router filter, which can be installed to perform advanced routing tasks. The router takes an incoming HTTP request, matches it to an upstream cluster, acquires a connection pool to a host in the upstream cluster, and forwards the request.
HTTP Metrics
OpenTelemetry is an open-source observability framework that provides a set of APIs, libraries, and instrumentation for collecting and exporting telemetry data. It includes semantic conventions for HTTP metrics, which provide a standardized way of collecting and reporting HTTP-related metrics. These metrics include HTTP response status codes, network protocol version, server address, server port, URL scheme, and more.
HTTP Upgrades
HTTP upgrades refer to the process of upgrading an HTTP connection to a different protocol, such as WebSocket or HTTP/2. HTTP upgrades allow for bi-directional communication between the client and server and can provide improved performance and functionality. Envoy supports HTTP upgrades and provides a way to configure custom filters for handling upgrade payloads.
Conclusion
HTTP is a fundamental technology for the World Wide Web and is commonly used for making requests to REST APIs or other web services. It is important to understand the basics of HTTP, including its protocols, connection management, routing, and metrics. Envoy is an open-source edge and service proxy that includes an HTTP connection manager and router, making it a popular choice for managing HTTP traffic in modern architectures.
