Open-source alternatives to Delay Queue

Kue is a Redis-backed job queue library for Node.js that provides a complete system for defining, scheduling, and processing background work. It stores job metadata and state in Redis lists and sorted sets, enabling persistent, in-memory operations with configurable concurrency control and priority-sorted processing. The library includes a RESTful HTTP API for managing jobs and a web-based monitoring dashboard for inspecting job status, progress, and logs. The system distinguishes itself through its event-driven worker model, where workers listen for job events via Redis pub/sub and process j

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Dramatiq is a distributed task queue and workload manager used to offload function execution to background workers. It functions as an asynchronous task orchestrator that enables the distribution of computational tasks across a cluster using a pluggable transport layer supporting RabbitMQ and Redis. The framework provides specialized tools for complex task orchestration, including the ability to link background jobs into sequences, pipelines, and barriers. It further manages distributed concurrency through the use of shared mutexes, rate limiters, and exponential backoff retries to prevent re

BullMQ is a Redis-backed message queue library and background processor designed for distributed task queueing. It functions as a distributed queue manager and task scheduler, utilizing Redis to manage asynchronous job processing and persistence. The system distinguishes itself through its role as a job workflow orchestrator, enabling the definition of complex parent-child job dependencies and hierarchies for multi-step workflows. It provides sandboxed process execution to isolate heavy workloads and prevent event loop blocking, alongside distributed rate limiting to protect downstream servic

Bull is a Node.js library for managing distributed jobs and message queues using Redis as the primary data store. It functions as a distributed task worker, job scheduler, and priority queue manager designed to handle asynchronous workloads across multiple processes. The project distinguishes itself by providing a persistent communication channel that decouples servers through the exchange of serializable data objects. It ensures distributed system reliability by detecting stalled tasks and recovering from process crashes to ensure every queued job is completed. The system covers a broad ran

Sidekiq is a background job processor and queue manager for Ruby that uses Redis to manage asynchronous tasks. It functions as a distributed task scheduler capable of handling periodic, delayed, and recurring jobs across a cluster of worker processes. The project features a job monitoring dashboard and administrative web interface for visualizing system state, tracking worker performance, and managing failed or dead jobs. It provides a distributed rate limiter to control execution frequency across multiple processes. The framework covers a broad range of operational capabilities, including j

Dragonfly is a high-performance, multi-model in-memory data store designed to serve as a drop-in replacement for existing database infrastructures. By utilizing a multi-threaded, shared-nothing architecture and a fiber-based concurrency model, it maximizes CPU utilization and minimizes latency for read and write operations. The system supports a wide range of data structures, including strings, hashes, lists, sets, sorted sets, and JSON documents, while maintaining full compatibility with standard industry wire protocols and client libraries. What distinguishes Dragonfly is its focus on effic

Godis is a Redis-compatible in-memory database and distributed key-value store. It functions as a replicated data store and distributed message broker, implementing the Redis protocol to manage complex data structures in memory. The system provides a geospatial indexing engine for proximity-based queries and distance calculations. It ensures high availability and data durability through master-slave replication and write-ahead logging. The project covers a wide range of capabilities including the management of strings, hash maps, lists, and sorted sets. It supports distributed data clusterin

Oban is a relational database-backed job processor and task scheduler for Elixir applications. It functions as a distributed workflow orchestrator that leverages database primitives to ensure job persistence, reliability, and consistent state management across clusters. The system distinguishes itself through complex workflow orchestration, enabling the composition of task dependencies using batching, sequential processing, and fan-out or fan-in patterns. It provides global throughput limiting and uniqueness enforcement to prevent duplicate work and protect downstream resources across distrib

This project is a PHP framework for offloading time-consuming tasks to background workers, enabling asynchronous processing to keep the main application request cycle responsive. It provides a unified interface for managing background job queues, allowing developers to decouple application logic from specific storage backends and message brokers. The system distinguishes itself through a driver-based abstraction layer that supports diverse infrastructure, including relational databases, Redis, and RabbitMQ. It manages the full lifecycle of background tasks, offering capabilities for delayed s

Osmedeus is a security workflow orchestration engine that coordinates AI agents, shell commands, and scanning tools through declarative YAML pipelines. It functions as a distributed security scanner, a declarative workflow automator, and an AI agent framework for security, enabling automated multi-step security analysis with conditional branching, parallel execution, and distributed workers. The engine distinguishes itself through a hybrid runner model that executes workflow steps on the local host, inside Docker containers, or over SSH to remote machines, selected per step or module. It supp

Eloquent-JavaScript is a comprehensive JavaScript programming textbook and interactive coding tutorial designed for web development education. It serves as both a language reference and a practical guide, combining theoretical lessons with an environment where learners can execute and modify code examples. The project focuses on the fundamental principles of the JavaScript language, including lexical scoping, prototype-based inheritance, and asynchronous patterns. It provides detailed instruction on object-oriented programming, functional programming, and the use of the browser DOM to create

TheHive is a security incident response platform and multi-tenant case management system. It functions as a Security Orchestration, Automation, and Response (SOAR) tool and a threat intelligence platform designed to coordinate security investigations by managing alerts, cases, and observables. The platform is distinguished by its multi-tenant architecture, which isolates data across different organizations while supporting selective cross-tenant sharing. It features a SOAR automation engine capable of executing sandboxed JavaScript logic to automate workflows and trigger response actions thro

rq is a distributed task queue and background worker system for Python that uses a Redis backend to decouple task submission from execution. It functions as a reliable message queue and task scheduler, allowing Python functions or asyncio coroutines to be processed asynchronously across multiple worker processes. The project distinguishes itself through reliable queuing mechanisms that prevent job loss during worker crashes using atomic operations. It provides specialized orchestration capabilities, including the prevention of duplicate jobs, job execution prioritization, and the ability to m

Mosquitto is a message broker that implements the MQTT protocol to route messages between connected devices and applications. It functions as a central hub for event-driven communication, supporting message exchange over both raw TCP and WebSockets. The software provides a persistent messaging infrastructure by writing message queues and client subscription states to disk, ensuring data recovery following service interruptions. The broker distinguishes itself through its support for distributed system synchronization, allowing for the federation of multiple remote brokers to share data across

Inngest is a durable execution framework and event-driven automation engine designed to orchestrate background workflows. It enables developers to build resilient, stateful processes by memoizing function steps, ensuring that long-running tasks can automatically resume from the last successful operation after failures, timeouts, or infrastructure restarts. The platform distinguishes itself through its event-driven architecture, which uses a schema-validated bus to trigger functions and coordinate complex, multi-step logic. It employs an onion-model middleware approach for cross-cutting concer

This project is a collection of learning resources and instructional guides for implementing asynchronous messaging patterns using RabbitMQ. It provides a series of tutorials and runnable code examples focused on the Advanced Message Queuing Protocol to help users decouple services via a message broker. The resources cover practical implementation patterns including request-reply, pub-sub, and stream processing. These guides demonstrate how to use official client libraries to balance worker loads, route messages across multiple consumers in a distributed system, and deploy high availability b

Go-workers is a background job processor for Go applications that coordinates asynchronous task execution using Redis queues. It implements the Sidekiq-compatible wire protocol and payload structures, allowing interoperability with existing background processing ecosystems and clients. The system manages task distribution through atomic list operations on a shared data store to guarantee reliable message delivery and prevent lost tasks during abrupt worker failures. It features configurable concurrency limits to control throughput per queue by dispatching incoming tasks across bounded synchr

RabbitMQ is a multi-protocol messaging broker that functions as an AMQP message broker, a clustered message queue, and a distributed message stream. It provides a server for translating and bridging communication between diverse messaging standards to connect heterogeneous systems. The system distinguishes itself through distributed broker clustering and federation, using shoveling mechanisms to synchronize data across geographically separate sites. It supports high-throughput, append-only logs for persisting and reading large sequences of messages for real-time processing. The broker covers

An asynchronous I/O and reactor event loop library for PHP, this project provides core primitives for coordinating non-blocking operations, managing system resources, and scheduling background tasks. The runtime executes concurrent operations by continuously running tick-based loop iterations that process pending timers, network streams, deferred callbacks, and system signals through efficient system-level polling mechanisms. The library coordinates event-driven execution using asynchronous timers for one-off or periodic tasks, next-tick deferred execution for breaking down workloads, and str

node-schedule is a job scheduler for Node.js that executes arbitrary functions based on specific dates or recurring rules. It functions as a date-based and event-driven scheduling system for JavaScript environments, allowing for the automation of one-off events and periodic tasks. The project supports recurring job scheduling through cron-style strings and recurrence rules, as well as the ability to schedule tasks for precise, single execution dates. It includes timezone-aware date calculations to map recurring rules against global or local time offsets. The system provides a comprehensive j

This project is a high-performance MQTT broker and IoT data platform designed to manage millions of concurrent device connections. It provides a scalable infrastructure for ingesting, processing, and routing telemetry data across distributed systems, utilizing an actor-based concurrency model to maintain high availability and state synchronization across cluster nodes. The platform distinguishes itself through integrated stream processing and edge computing capabilities. It allows users to execute declarative SQL-based rules directly against incoming message streams for real-time filtering, t

pg-boss is a background task scheduler and distributed task queue that uses PostgreSQL as a reliable message broker for asynchronous job processing. It provides a system for distributing work across multiple application instances, ensuring exactly-once delivery through atomic database transactions. The project includes a cron job scheduler for automating recurring tasks and a PostgreSQL pub-sub system for fan-out event distribution. It also features a web-based management dashboard for monitoring queue statistics and controlling job lifecycles, including manual retries and cancellations. Cap

Sidekiq is a Ruby background processing framework and asynchronous task runner. It functions as a Redis-backed background job processor that offloads heavy or time-consuming work from web requests to separate worker processes to ensure the main application remains responsive. The system operates as a Redis task queue, storing pending jobs in Redis to be processed concurrently by multiple threads. It provides a framework for distributed task queueing and asynchronous job scheduling to coordinate work across multiple server instances. The project covers Ruby application scaling by executing ba

FastStream is an asyncio message broker framework for building event-driven applications in Python. It provides a unified interface and a multi-broker messaging abstraction layer that translates generic producer and consumer calls into broker-specific APIs. The framework features a built-in dependency injection container and uses decorators to route messages to asynchronous handler functions. It includes a documentation generator that extracts channel definitions and message formats from code to produce standardized AsyncAPI specifications. The project supports integration with Kafka, Rabbit

Resque is a Ruby library for enqueueing and processing asynchronous tasks using Redis as a data store. It functions as a distributed task processor and queue manager, allowing long-running work to be moved out of the main request cycle. The system executes background jobs in isolated child processes to prevent memory leaks and provides a web-based dashboard for monitoring queue depths, worker activity, and failed job statistics. Capability areas include distributed worker coordination via signals, error handling with job retry mechanisms, and priority-ordered queue management. It also suppor

Asynq is a distributed background job processing framework for Go applications. It manages asynchronous task queues by offloading heavy operations to persistent storage, allowing the main application to remain responsive while background workers handle workloads. The system utilizes Redis to manage task state, concurrency, and message distribution across multiple worker instances. It employs atomic Lua scripting and sorted sets to ensure reliable job acquisition, precise scheduling of delayed tasks, and fault-tolerant processing through a two-stage acknowledgement flow. The framework support