ClusterCron unstable

Runs recurring cron jobs through cluster sharding.

This module turns a Cron.Cron schedule into a Layer that coordinates one recurring job across a cluster. It registers a singleton for the initial scheduling step and a persisted entity message for each run. This is useful for distributed maintenance work where the job should be owned by the cluster rather than by every runner independently.

With calculateNextRunFromPrevious, every run is processed by a single entity per cron job, so runs never overlap and are caught up in order. The scheduled time of the current run is available through CurrentScheduledTime.

2 exports Since v4.0.0 Source

Constructors

make

unstable

Since v4.0.0

Creates a layer that runs a cron job through the cluster sharding system.

Details

The job is scheduled as persisted entity messages, with an initial singleton scheduling step and optional controls for shard group, next-run calculation, and skipping stale scheduled runs.

Signature

declare function make<E, R>(options: {
  readonly calculateNextRunFromPrevious?: boolean;
  readonly cron: Cron;
  readonly execute: Effect<void, E, R>;
  readonly name: string;
  readonly shardGroup?: string;
  readonly skipIfOlderThan?: Input;
}): Layer<never, never, Sharding | Exclude<Exclude<R, CurrentScheduledTime>, Scope>>

Services

CurrentScheduledTime

unstable

Since v4.0.0

Service tag for the scheduled time of the cron run currently executing.

When to use

Use to read the time the current run was scheduled for, inside the execute effect of make.

Signature

declare class CurrentScheduledTime extends Shape<"effect/cluster/ClusterCron/CurrentScheduledTime", Utc, this> {
  constructor(_: never);
}