Observability

RedisTelemetry records Effect metrics and, optionally, spans for calls made through the Redis service. It is off by default, and the package has no logging.

Enabling telemetryCopy Anchor Link

Merge RedisTelemetry.layer with your runtime layer. Metrics are on and tracing is off unless you say otherwise.

Example (Enabling Metrics and Spans)

import { Layer } from "effect";
import { RedisTelemetry } from "@effect-kit/redis";
import { RedisNode } from "@effect-kit/redis/node";

const RedisLive = RedisNode.layer({ url: "redis://localhost:6379" });

export const RedisObserved = Layer.merge(
  RedisLive,
  RedisTelemetry.layer({ metrics: true, tracing: true }),
);

Without the layer, both are off and instrumented calls skip the work. Telemetry adds no service to the requirements of a command.

The package does not export anything. Exporters for metrics and traces belong to your application, for example an OpenTelemetry layer.

MetricsCopy Anchor Link

Each operation is a command, a pipeline or a transaction. A pipeline or transaction counts once, not once per command inside it.

outcome is success, failure, defect or interrupted. The histogram boundaries are 0, 0.1, 0.5, 1, 2, 5, 10, 50, 100, 500, 1000, 5000 and 30000 milliseconds.

Example (Reading the Redis Metrics)

import { Effect, Metric } from "effect";

export const redisMetrics = Effect.gen(function* () {
  const metrics = yield* Metric.snapshot;
  return metrics.filter((metric) => metric.id.startsWith("effect_redis."));
});

SpansCopy Anchor Link

With tracing: true, each operation runs in a span named redis.command, redis.pipeline or redis.transaction, with kind client and an outcome attribute. On failure the span ends with a fixed RedisOperationFailure value and the outcome, never your error.

What is never recordedCopy Anchor Link

Names and attributes never come from command arguments. The command name, keys and values are not recorded, so you cannot get per-command or per-key metrics from this layer.

Inspecting pools and subscriptionsCopy Anchor Link

RedisSessions and RedisPubSub expose a snapshot effect that reports their current state without any telemetry setup.

Example (Reading Pool and Subscription State)

import { Effect } from "effect";
import { RedisPubSub, RedisSessions } from "@effect-kit/redis";

export const state = Effect.gen(function* () {
  const sessions = yield* RedisSessions;
  const pubsub = yield* RedisPubSub;

  const pool = yield* sessions.snapshot;
  const subscriptions = yield* pubsub.snapshot;

  return { leased: pool.leased, idle: pool.idle, listeners: subscriptions.listeners };
});

sessions.snapshot reports closed, waiting, leased, connections, idle, generations and retired. pubsub.snapshot reports generation, listeners, retiring, interests and retainedBytes.