Operate services

A running program can watch your Modal services and steer them: read a function’s backlog and an App’s logs, scale ahead of traffic, and roll a deploy back. Each is a binding, so the host gets only the access that one call needs.

Watch a function’s backlog

const embed = yield* Modal.ReadFunction(Embed);
const { backlog, runningInputs } = yield* embed.stats();

timeRangeStats, metrics, calls and callCount cover history.

Scale ahead of traffic

const generate = yield* Modal.ScaleFunction(Generate);
yield* generate.update({ minContainers: 4, bufferContainers: 2 });

The override lasts until the next deploy.

Read a server’s requests

const api = yield* Modal.ReadServer(Api);
const recent = yield* api.requests({ limit: 20 });
const stats = yield* api.stats({ since: new Date(Date.now() - 600_000) });

Read an App’s logs

const backend = yield* Modal.ReadApp(Backend);
const errors = yield* backend.logs({ since: new Date(Date.now() - 3_600_000), stream: "stderr" });

Logs cover every function, server and sandbox in the App.

Roll a deploy back

const backend = yield* Modal.WriteApp(Backend);
yield* backend.rollback();

rollover, promote and stop are on the same client.