Rust Microservices In Server-Side WebAssembly

The Rust programming language has gained mainstream adoption in the past several years. It is consistently ranked as the most Rust server hosting beloved programming language by developers and has been accepted into the Linux kernel. Rust enables developers to write correct and memory-safe programs that are as fast and as small as C programs. It is ideally suited for infrastructure software, including server-side applications, that require high reliability and performance.

However, for server-side applications, Rust also presents some challenges. Rust programs are compiled into native machine code, which is not portable and is unsafe in multi-tenancy cloud environments. We also lack tools to manage and orchestrate native applications in the cloud.

Hence, server-side Rust applications commonly run inside VMs or Linux containers, which bring significant memory and CPU overhead. This diminishes Rust’s advantages in efficiency and makes it hard to deploy services in resource-constrained environments, such as edge data centers and edge clouds. The solution to this problem is WebAssembly (Wasm).

Started as a secure runtime inside web browsers, Wasm programs can be securely isolated in their own sandbox. With a new generation of Wasm runtimes, such as the Cloud Native Computing Foundation’s WasmEdge Runtime, you can now run Wasm applications on the server. You can compile Rust programs to Wasm bytecode, and then deploy the Wasm application in the cloud.