@systemfsoftware/effect-daemon-cluster

The @systemfsoftware/effect-daemon-spec medium over effect/cluster: cluster entities and single-owner singletons are supervised with inferred death and eventual group stop.

Installation

pnpm add @systemfsoftware/effect-daemon-cluster

Features

• Entities and single-owner singletons: a child is either an entity reached by a direct liveness call, or a Singleton.make-style single-owner effect whose registration lifetime is the incarnation.
• Inferred death, never RunnerHealth: the medium's liveness probe calls the child directly; a failing singleton run becomes a defect, and a death the medium cannot observe is reported as an inferred failure.
• The declared loss: the medium declares { reporting: 'inferred', groupStop: 'eventual' }, so the conformance kit holds it only to what it can observe and honour.
• Proven, not asserted: ClusterMedium.conformanceDriver runs the whole scenario catalogue against the fiber reference.

Usage

import { ClusterMedium } from '@systemfsoftware/effect-daemon-cluster'
import { Supervisor } from '@systemfsoftware/effect-daemon-spec'
import { Effect } from 'effect'
import { SingleRunner } from 'effect/cluster'

const handleOrders = (ready: Effect.Effect<void>) => Effect.andThen(ready, serveOrders)

const spec = Supervisor.make('cluster-workers').pipe(
  Supervisor.children([
    Supervisor.ChildSpecs.on(ClusterMedium.port)(
      'orders',
      ClusterMedium.singletonChild({ name: 'orders', run: handleOrders }),
      { restartType: 'permanent' },
    ),
  ]),
)

// `ClusterRunner` is `SingleRunner.layer(options)` provided with a `SqlClient` and `Crypto`.
const program = work.pipe(
  Effect.provide(spec.layer),
  Effect.provide(ClusterMedium.layer()),
  Effect.provide(ClusterRunner),
)

ClusterMedium.layer(options?) binds the port at the composition root, so a tree can mix media; options.shardGroup sets the shard group singleton children register under. An entity child is declared with ClusterMedium.entityChild({ entity, entityId, register, probe }), where probe is the direct liveness call to the entity.

Conformance

import { ClusterMedium } from '@systemfsoftware/effect-daemon-cluster'
import { Conformance } from '@systemfsoftware/effect-daemon-conformance'
import { Effect } from 'effect'

const report = yield* Conformance.prove(ClusterMedium.conformanceDriver)
Conformance.isConforming(report)

License

Apache-2.0