Runtimes & Languages
Serverless Execution: Docker Containers vs WebAssembly
Compare cold-start times and memory footprints of Serverless Docker Containers versus WebAssembly (Wasm) runtimes.
Test Environment
CPUAWS Graviton3
RAM16GB
OSAmazon Linux 2
ToolCustom Runner
Metrics Comparison
Cold Start Time
Unit: msWasmtime
2★
Docker/containerd
850
Detailed Analysis
Wasm achieves microsecond cold starts and tiny memory footprints, making it the ideal future format for edge computing and serverless.
Containers require full namespace and cgroup setup. Wasm simply loads bytecode into a lightweight memory sandbox.
Process Isolation
Setting up security boundaries
Bottleneck: Linux namespaces are heavy compared to Wasm memory bounds checking.
Architectural Recommendations
- Explore Wasm for Edge functions (e.g. Cloudflare Workers)
- Containers remain essential for legacy apps
Frequently Asked Questions
Can Wasm access the filesystem?
Only if explicitly granted via WASI (WebAssembly System Interface).