Wasm runtime
The following runtimes are supported by Envoy:
| Name | Description | 
|---|---|
| envoy.wasm.runtime.v8 | V8-based runtime | 
| envoy.wasm.runtime.wamr | WAMR runtime | 
| envoy.wasm.runtime.wasmtime | Wasmtime runtime | 
| envoy.wasm.runtime.wavm | WAVM runtime | 
| envoy.wasm.runtime.null | Compiled modules linked into Envoy | 
WAMR(WASM-Micro-Runtime), Wasmtime and WAVM runtimes are not included in Envoy release image by default.
Wasm runtime emits the following statistics:
| Name | Type | Description | 
|---|---|---|
| wasm.<runtime>.created | Counter | Total number of execution instances created | 
| wasm.<runtime>.active | Gauge | Number of active execution instances |