vectordotdev/vrl

Vector Remap Language (VRL)

VRL is a scripting language for processing observability data (logs, metrics, traces). Although VRL was originally created for use in Vector, it was designed to be generic and re-usable in many contexts.

VRL is designed around two core principles:

• Safety — programs won't compile unless all errors from fallible functions are explicitly handled, eliminating unexpected runtime failures.
• Performance — programs are compiled at startup and run with near-native performance, with no garbage collection or runtime overhead.

VRL is stateless and expression-oriented, each program processes a single event and every expression returns a value.

VRL is maintained by Datadog's Community Open Source Engineering team.

WebAssembly

VRL can be compiled with the wasm32-unknown-unknown target:

cargo check --target wasm32-unknown-unknown --no-default-features --features stdlib

Most stdlib functions are supported. The following functions compile but abort at runtime due to platform limitations (I/O, system calls, or native dependencies):

• dns_lookup
• get_hostname
• http_request
• log
• parse_grok
• parse_groks
• reverse_dns
• validate_json_schema

Note: the grok parser within the datadog feature is excluded entirely when targeting wasm32.