Simple, reliable and efficient concurrent work queue for Prisma + PostgreSQL
- Leverages PostgreSQL SKIP LOCKED feature to reliably dequeue jobs
- Supports crontab syntax for complex scheduled jobs
- Pluggable retry strategies with exponential backoff by default
- Cooperative worker cancellation via
AbortSignal - Separate
jobError/errorevents for clean observability - Compatible with Prisma 7+ and any Prisma driver adapter (e.g.
@prisma/adapter-pg) - Written in TypeScript for static type checking with exported types along the library.
- Built by tsup to provide both CommonJS and ESM packages.
npm install @mgcrea/prisma-queue --save
# or
pnpm add @mgcrea/prisma-queueThis library requires Prisma 7+ with a driver adapter:
pnpm add @prisma/client @prisma/adapter-pg-
Append the
QueueJobmodel to yourschema.prismafile -
Create your queue
import { createQueue } from "@mgcrea/prisma-queue";
import { prisma } from "./prisma"; // your PrismaClient instance
type JobPayload = { email: string };
type JobResult = { status: number };
export const emailQueue = createQueue<JobPayload, JobResult, typeof prisma>(
{ prisma, name: "email" },
async (job, client) => {
const { id, payload } = job;
console.log(`Processing job#${id} with payload=${JSON.stringify(payload)})`);
// await someAsyncMethod();
await job.progress(50);
const status = 200;
if (Math.random() > 0.5) {
throw new Error(`Failed for some unknown reason`);
}
console.log(`Finished job#${id} with status=${status}`);
return { status };
},
);Note: The
clientparameter in the worker is a transaction-scoped client (in the default transactional mode) with full typed access to your Prisma models. TypeScript infers the client type from theprismaoption you pass.
- Queue a job
import { emailQueue } from "./emailQueue";
const main = async () => {
const job = await emailQueue.enqueue({ email: "foo@bar.com" });
};
main();- Schedule a recurring job
import { emailQueue } from "./emailQueue";
const main = async () => {
const nextJob = await queue.schedule(
{ key: "email-schedule", cron: "5 5 * * *" },
{ email: "foo@bar.com" },
);
};
main();- Start queue processing (usually in another process)
import { emailQueue } from "./emailQueue";
const main = async () => {
await queue.start();
};
main();| Option | Type | Default | Description |
|---|---|---|---|
prisma |
PrismaClient |
(required) | Your Prisma client instance |
name |
string |
"default" |
Queue name for partitioning jobs |
maxAttempts |
number | null |
null |
Max retry attempts (null = unlimited) |
maxConcurrency |
number |
1 |
Max concurrent jobs |
pollInterval |
number |
10000 |
Polling interval in ms |
jobInterval |
number |
50 |
Delay between job dispatches in ms |
tableName |
string |
"queue_jobs" |
Database table name (must match @@map in your schema) |
deleteOn |
"success" | "failure" | "always" | "never" |
"never" |
When to delete completed jobs |
transactionTimeout |
number |
1800000 |
Transaction timeout in ms (30 min) |
retryStrategy |
RetryStrategy |
Exponential backoff | Custom retry logic |
transactional |
boolean |
true |
Run worker inside the dequeue transaction |
The queue emits typed events:
queue.on("enqueue", (job) => {
console.log(`Job ${job.id} enqueued`);
});
queue.on("dequeue", (job) => {
console.log(`Job ${job.id} picked up for processing`);
});
queue.on("success", (result, job) => {
console.log(`Job ${job.id} succeeded with`, result);
});
// Job execution failures (worker threw)
queue.on("jobError", (error, job) => {
console.error(`Job ${job.id} failed:`, error);
});
// System/infrastructure errors (poll failures, cron scheduling errors)
queue.on("error", (error) => {
console.error("Queue system error:", error);
});By default, failed jobs are retried with exponential backoff (2^attempts seconds + jitter). You can provide a custom retryStrategy:
import { createQueue, type RetryContext } from "@mgcrea/prisma-queue";
const queue = createQueue<JobPayload, JobResult, typeof prisma>(
{
prisma,
name: "email",
maxAttempts: 5,
retryStrategy: ({ attempts, maxAttempts, error }: RetryContext) => {
// Return delay in ms, or null to stop retrying
if (maxAttempts !== null && attempts >= maxAttempts) return null;
// Linear backoff: 1s, 2s, 3s, ...
return 1000 * attempts;
},
},
async (job, client) => {
// ...
},
);Dequeued jobs expose an AbortSignal that is triggered when queue.stop() is called. Use it to cooperatively cancel long-running work:
const queue = createQueue<JobPayload, JobResult, typeof prisma>(
{ prisma, name: "email" },
async (job, client) => {
for (const item of items) {
if (job.signal.aborted) {
throw new Error("Job cancelled");
}
await processItem(item);
}
return { status: "done" };
},
);By default, the worker runs inside the dequeue transaction (exactly-once semantics). Set transactional: false to run the worker outside the transaction, giving it access to the full PrismaClient with $transaction support (at-least-once semantics):
import { createQueue, type JobWorkerWithClient } from "@mgcrea/prisma-queue";
const queue = createQueue<JobPayload, JobResult, typeof prisma>(
{ prisma, name: "email", transactional: false },
async (job, client) => {
// client is the full PrismaClient — $transaction is available
await client.$transaction(async (tx) => {
await tx.user.update({ where: { id: 1 }, data: { email: job.payload.email } });
await tx.auditLog.create({ data: { action: "email_updated" } });
});
return { status: 200 };
},
);Trade-offs: In non-transactional mode, a process crash between claiming and completing a job can leave it "stuck" (processedAt set, finishedAt null). Use requeueStale() to recover:
// Requeue jobs claimed more than 5 minutes ago that never completed
const count = await queue.requeueStale({ olderThanMs: 5 * 60 * 1000 });Note: isLocked() returns false during worker execution in non-transactional mode since the row lock is released after claiming.
You can easily spin of your workers in separate threads using worker_threads (Node.js >= 12.17.0).
It enables you to fully leverage your CPU cores and isolate your main application queue from potential memory leaks or crashes.
import { JobPayload, JobResult, PrismaJob } from "@mgcrea/prisma-queue";
import { Worker } from "node:worker_threads";
import { ROOT_DIR } from "src/config/env";
import { log } from "src/config/log";
const WORKER_SCRIPT = `${ROOT_DIR}/dist/worker.js`;
export const processInWorker = async <P extends JobPayload, R extends JobResult>(
job: PrismaJob<P, R>,
): Promise<R> =>
new Promise((resolve, reject) => {
const workerData = getJobWorkerData(job);
log.debug(`Starting worker thread for job id=${job.id} in queue=${job.record.queue}`);
try {
const worker = new Worker(WORKER_SCRIPT, {
workerData,
});
worker.on("message", resolve);
worker.on("error", reject);
worker.on("exit", (code) => {
if (code !== 0) {
reject(
new Error(
`Worker for job id=${job.id} in queue=${job.record.queue} stopped with exit code ${code}`,
),
);
}
});
} catch (error) {
reject(error as Error);
}
});
// eslint-disable-next-line @typescript-eslint/no-explicit-any
export type JobWorkerData<P extends JobPayload = any> = {
id: bigint;
payload: P;
queue: string;
};
const getJobWorkerData = <P extends JobPayload, R extends JobResult>(job: PrismaJob<P, R>): JobWorkerData => {
// Prepare the job data for structured cloning in worker thread
return {
id: job.id,
payload: job.payload,
queue: job.record.queue,
};
};worker.ts
import { parentPort, workerData } from "node:worker_threads";
import { log } from "src/config/log";
import { workers } from "src/queue";
import { type JobWorkerData } from "src/utils/queue";
import { logMemoryUsage } from "./utils/system";
log.info(`Worker thread started with data=${JSON.stringify(workerData)}`);
const typedWorkerData = workerData as JobWorkerData;
const { queue } = typedWorkerData;
const workerName = queue.replace(/Queue$/, "Worker") as keyof typeof workers;
log.debug(`Importing worker ${workerName} for queue=${queue}`);
const jobWorker = workers[workerName];
// eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
if (!jobWorker) {
log.error(`No worker found for queue=${queue}`);
process.exit(1);
}
log.info(`Running worker for queue=${queue}`);
const result = await jobWorker(typedWorkerData);
log.info(`Worker for queue=${queue} completed with result=${JSON.stringify(result)}`);
parentPort?.postMessage(result);
process.exit(0);v2.0 drops @prisma/client imports entirely, making the library compatible with Prisma 7+ and its new prisma-client generator. This is a breaking release.
1. prisma option is now required
The library no longer creates a default PrismaClient. You must pass your own instance:
// v1
const queue = createQueue({ name: "email" }, worker);
// v2
import { prisma } from "./prisma";
const queue = createQueue({ prisma, name: "email" }, worker);2. Third type parameter C for client type
createQueue and PrismaQueue now accept a third generic C that represents your PrismaClient type. TypeScript infers C from the prisma option, but if you explicitly specify type parameters, you must include all three:
// v1
createQueue<MyPayload, MyResult>({ name: "email" }, worker);
// v2
createQueue<MyPayload, MyResult, typeof prisma>({ prisma, name: "email" }, worker);3. Peer dependency: Prisma 7+
The peer dependency changed from @prisma/client >=3 <7 to @prisma/client >=7 plus @prisma/adapter-pg >=7. You need a Prisma driver adapter:
pnpm add @prisma/client @prisma/adapter-pg pgAnd configure your PrismaClient with the adapter:
import { PrismaPg } from "@prisma/adapter-pg";
import { PrismaClient } from "./prisma/client/client.js";
const adapter = new PrismaPg({ connectionString: process.env.DATABASE_URL });
export const prisma = new PrismaClient({ adapter });4. tableName defaults to "queue_jobs"
DMMF-based table name auto-detection has been removed. The default is now "queue_jobs" (matching the @@map in the documented schema). If you use a custom table name, pass it explicitly:
createQueue({ prisma, name: "email", tableName: "my_custom_table" }, worker);5. PrismaLightClient type removed
The PrismaLightClient type has been replaced by TransactionClient<C>, which is computed from your actual PrismaClient type. If you referenced PrismaLightClient in your code, replace it with TransactionClient<typeof prisma>.
6. void is now a valid JobResult
Workers that don't return a value no longer need to return null. void is accepted as a result type:
type ScanResult = void;
createQueue<ScanPayload, ScanResult, typeof prisma>({ prisma, name: "scan" }, async (job, client) => {
// no return needed
});The database schema, table structure, and indexes are unchanged from v1.x. No migration is needed for your database.
Inspired by
- pg-queue by
The MIT License
Copyright (c) 2022 Olivier Louvignes <olivier@mgcrea.io>
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