Merge pull request #2153 from poolifier/combined-prs-branch
[poolifier.git] / README.md
index ed9df457b3f6227465ece3458a7e5342a0d2adf8..db52c8c2c8ebb92fc50c2912a4875a6519750c99 100644 (file)
--- a/README.md
+++ b/README.md
 <div align="center">
-<img src="./docs/logo.png" width="340px" height="266px"/>
+  <img src="./images/logo.png" width="340px" height="266px"/>
 </div>
 
-<h2 align="center">Node Thread Pool :arrow_double_up: :on:</h2>
-
-<p align="center">
-  <a href="https://www.npmjs.com/package/poolifier">
-    <img alt="Weekly Downloads" src="https://img.shields.io/npm/dw/poolifier"></a>
-  <a href="https://github.com/pioardi/node-pool/actions">
-    <img alt="Actions Status" src="https://github.com/pioardi/node-pool/workflows/NodeCI/badge.svg"></a>
-  <a href="https://sonarcloud.io/dashboard?id=pioardi_poolifier">
-    <img alt="Quality Gate Status" src="https://sonarcloud.io/api/project_badges/measure?project=pioardi_poolifier&metric=alert_status"></a>
-  <a href="https://sonarcloud.io/component_measures/metric/coverage/list?id=pioardi_poolifier">
-    <img alt="Code coverage" src="https://sonarcloud.io/api/project_badges/measure?project=pioardi_poolifier&metric=coverage"></a>
-  <a href="https://standardjs.com">
-    <img alt="Javascript Standard Style Guide" src="https://img.shields.io/badge/code_style-standard-brightgreen.svg"></a>
-  <a href="https://gitter.im/poolifier/community?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge">
-    <img alt="Gitter chat" src="https://badges.gitter.im/poolifier/community.svg"></a>
-  <a href="https://badgen.net/dependabot/dependabot/dependabot-core/?icon=dependabot">
-    <img alt="Dependabot" src="https://badgen.net/dependabot/dependabot/dependabot-core/?icon=dependabot"></a>
-  <a href="http://makeapullrequest.com">
-    <img alt="PR Welcome" src="https://img.shields.io/badge/PRs-welcome-brightgreen.svg?style=flat-square"></a>
-  <a href="https://img.shields.io/static/v1?label=dependencies&message=no%20dependencies&color=brightgreen">
-    <img alt="No dependencies" src="https://img.shields.io/static/v1?label=dependencies&message=no%20dependencies&color=brightgreen"></a>
-</p>
+<div align="center">
+
+# Node.js Worker_Threads and Cluster Worker Pool
+
+</div>
+
+<div align="center">
+
+[![GitHub commit activity (master)](https://img.shields.io/github/commit-activity/m/poolifier/poolifier/master?color=brightgreen&logo=github)](https://github.com/poolifier/poolifier/graphs/commit-activity)
+[![Npm Version](https://badgen.net/npm/v/poolifier?icon=npm)](https://www.npmjs.com/package/poolifier)
+[![Npm Weekly Downloads](https://badgen.net/npm/dw/poolifier?icon=npm)](https://www.npmjs.com/package/poolifier)
+[![JSR Version](https://jsr.io/badges/@poolifier/poolifier)](https://jsr.io/@poolifier/poolifier)
+[![CI Workflow](https://github.com/poolifier/poolifier/actions/workflows/ci.yml/badge.svg)](https://github.com/poolifier/poolifier/actions/workflows/ci.yml)
+[![Code Coverage](https://sonarcloud.io/api/project_badges/measure?project=poolifier_poolifier&metric=coverage)](https://sonarcloud.io/dashboard?id=poolifier_poolifier)
+[![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=poolifier_poolifier&metric=alert_status)](https://sonarcloud.io/dashboard?id=poolifier_poolifier)
+[![Javascript Standard Style Guide](<https://badgen.net/static/code style/standard/green>)](https://standardjs.com)
+[![Discord](https://badgen.net/discord/online-members/vXxZhyb3b6?icon=discord&label=discord&color=green)](https://discord.gg/vXxZhyb3b6)
+[![Open Collective](https://opencollective.com/poolifier/tiers/badge.svg)](https://opencollective.com/poolifier)
+[![PRs Welcome](https://badgen.net/static/PRs/welcome/green)](https://makeapullrequest.com)
+[![No Dependencies](<https://badgen.net/static/dependencies/no dependencies/green>)](<https://badgen.net/static/dependencies/no dependencies/green>)
+
+</div>
 
 ## Why Poolifier?
 
-Poolifier is used to perform heavy CPU bound tasks on nodejs servers, it implements worker pools (yes, more worker pool implementations, so you can choose which one fit better for you) using [worker-threads](https://nodejs.org/api/worker_threads.html#worker_threads_worker_threads).  
+Poolifier is used to perform CPU and/or I/O intensive tasks on Node.js servers, it implements worker pools using [worker_threads](https://nodejs.org/api/worker_threads.html) and [cluster](https://nodejs.org/api/cluster.html) Node.js modules.  
 With poolifier you can improve your **performance** and resolve problems related to the event loop.  
-Moreover you can execute your CPU tasks using an API designed to improve the **developer experience**.
-
-- Performance :racehorse:
-- Security :bank: :cop: [![Security Rating](https://sonarcloud.io/api/project_badges/measure?project=pioardi_poolifier&metric=security_rating)](https://sonarcloud.io/dashboard?id=pioardi_poolifier) [![Vulnerabilities](https://sonarcloud.io/api/project_badges/measure?project=pioardi_poolifier&metric=vulnerabilities)](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
-- Easy to use :couple:
-- Easy switch from a pool to another, easy to tune :heavy_check_mark:
-- Dynamic pool size :heavy_check_mark:
-- No runtime dependencies :heavy_check_mark:
-- Proper async integration with node async hooks :heavy_check_mark:
-- Support for worker threads and cluster node modules :heavy_check_mark:
-- Support sync and async tasks :heavy_check_mark:
-- General guidance on pools to use :heavy_check_mark:
-- Widely tested :heavy_check_mark:
-- Error handling out of the box :heavy_check_mark:
-- Active community :heavy_check_mark:
-- Code quality :octocat: [![Bugs](https://sonarcloud.io/api/project_badges/measure?project=pioardi_poolifier&metric=bugs)](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
-  [![Code Smells](https://sonarcloud.io/api/project_badges/measure?project=pioardi_poolifier&metric=code_smells)](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
-  [![Duplicated Lines (%)](https://sonarcloud.io/api/project_badges/measure?project=pioardi_poolifier&metric=duplicated_lines_density)](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
-  [![Maintainability Rating](https://sonarcloud.io/api/project_badges/measure?project=pioardi_poolifier&metric=sqale_rating)](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
-  [![Reliability Rating](https://sonarcloud.io/api/project_badges/measure?project=pioardi_poolifier&metric=reliability_rating)](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
-  [![Technical Debt](https://sonarcloud.io/api/project_badges/measure?project=pioardi_poolifier&metric=sqale_index)](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
-
-## Contents
-
-<h3 align="center">
-  <a href="#overview">Overview</a>
-  <span> · </span>
-  <a href="#installation">Installation</a>
-  <span> · </span>
-  <a href="#usage">Usage</a>
-  <span> · </span>
-  <a href="#node-versions">  Node versions</a>
-  <span> · </span>
-  <a href="#api">API</a>
-  <span> · </span>
-  <a href="#choose-your-pool">Choose your pool</a>
-  <span> · </span>
-  <a href="#contribute">Contribute</a>
-  <span> · </span>
-  <a href="#team">Team</a>
-  <span> · </span>
-  <a href="#license">License</a>
-</h3>
+Moreover you can execute your tasks using an API designed to improve the **developer experience**.  
+Please consult our [general guidelines](#general-guidelines).
+
+- Easy to use :white_check_mark:
+- Fixed and dynamic pool size :white_check_mark:
+- Easy switch from a pool type to another :white_check_mark:
+- Performance [benchmarks](./benchmarks/README.md) :white_check_mark:
+- No runtime dependencies :white_check_mark:
+- Proper integration with Node.js [async_hooks](https://nodejs.org/api/async_hooks.html) :white_check_mark:
+- Support for CommonJS, ESM and TypeScript :white_check_mark:
+- Support for [worker_threads](https://nodejs.org/api/worker_threads.html) and [cluster](https://nodejs.org/api/cluster.html) Node.js modules :white_check_mark:
+- Support for multiple task functions :white_check_mark:
+- Support for task functions [CRUD](https://en.wikipedia.org/wiki/Create,_read,_update_and_delete) operations at runtime :white_check_mark:
+- Support for sync and async task functions :white_check_mark:
+- Tasks distribution strategies :white_check_mark:
+- Lockless tasks queueing :white_check_mark:
+- Queued tasks rescheduling:
+  - Task stealing on idle :white_check_mark:
+  - Tasks stealing under back pressure :white_check_mark:
+  - Tasks redistribution on worker error :white_check_mark:
+- General guidelines on pool choice :white_check_mark:
+- Error handling out of the box :white_check_mark:
+- Widely tested :white_check_mark:
+- Active community :white_check_mark:
+- Code quality [![Bugs](https://sonarcloud.io/api/project_badges/measure?project=poolifier_poolifier&metric=bugs)](https://sonarcloud.io/dashboard?id=poolifier_poolifier)
+  [![Code Smells](https://sonarcloud.io/api/project_badges/measure?project=poolifier_poolifier&metric=code_smells)](https://sonarcloud.io/dashboard?id=poolifier_poolifier)
+  [![Duplicated Lines (%)](https://sonarcloud.io/api/project_badges/measure?project=poolifier_poolifier&metric=duplicated_lines_density)](https://sonarcloud.io/dashboard?id=poolifier_poolifier)
+  [![Maintainability Rating](https://sonarcloud.io/api/project_badges/measure?project=poolifier_poolifier&metric=sqale_rating)](https://sonarcloud.io/dashboard?id=poolifier_poolifier)
+  [![Reliability Rating](https://sonarcloud.io/api/project_badges/measure?project=poolifier_poolifier&metric=reliability_rating)](https://sonarcloud.io/dashboard?id=poolifier_poolifier)
+  [![Technical Debt](https://sonarcloud.io/api/project_badges/measure?project=poolifier_poolifier&metric=sqale_index)](https://sonarcloud.io/dashboard?id=poolifier_poolifier)
+- Code security [![Security Rating](https://sonarcloud.io/api/project_badges/measure?project=poolifier_poolifier&metric=security_rating)](https://sonarcloud.io/dashboard?id=poolifier_poolifier) [![Vulnerabilities](https://sonarcloud.io/api/project_badges/measure?project=poolifier_poolifier&metric=vulnerabilities)](https://sonarcloud.io/dashboard?id=poolifier_poolifier)
+
+## Table of contents
+
+- [Overview](#overview)
+- [Installation](#installation)
+- [Usage](#usage)
+- [Node.js versions](#nodejs-versions)
+- [API](#api)
+- [General guidelines](#general-guidelines)
+- [Worker choice strategies](#worker-choice-strategies)
+- [Contribute](#contribute)
+- [Team](#team)
+- [License](#license)
 
 ## Overview
 
-Node pool contains two [worker-threads](https://nodejs.org/api/worker_threads.html#worker_threads_worker_threads)/[cluster worker](https://nodejs.org/api/cluster.html#cluster_class_worker) pool implementations, you don't have to deal with worker-threads/cluster worker complexity.  
-The first implementation is a static worker pool, with a defined number of workers that are started at creation time and will be reused.  
-The second implementation is a dynamic worker pool with a number of worker started at creation time (these workers will be always active and reused) and other workers created when the load will increase (with an upper limit, these workers will be reused when active), the new created workers will be stopped after a configurable period of inactivity.  
-You have to implement your worker extending the ThreadWorker or ClusterWorker class
+Poolifier contains two [worker_threads](https://nodejs.org/api/worker_threads.html#class-worker)/[cluster](https://nodejs.org/api/cluster.html#cluster_class_worker) worker pool implementations, you don't have to deal with [worker_threads](https://nodejs.org/api/worker_threads.html)/[cluster](https://nodejs.org/api/cluster.html) complexity.  
+The first implementation is a fixed worker pool, with a defined number of workers that are started at creation time and will be reused.  
+The second implementation is a dynamic worker pool, with a number of worker started at creation time (these workers will be always active and reused) and other workers created when the load will increase (with an upper limit, these workers will be reused when active), the newly created workers will be stopped after a configurable period of inactivity.  
+You have to implement your worker by extending the _ThreadWorker_ or _ClusterWorker_ class.
 
 ## Installation
 
+### npm
+
 ```shell
 npm install poolifier --save
 ```
 
+### jsr
+
+```shell
+npx jsr add @poolifier/poolifier
+```
+
 ## Usage
 
-You can implement a worker-threads worker in a simple way by extending the class ThreadWorker:
+You can implement a poolifier [worker_threads](https://nodejs.org/api/worker_threads.html#class-worker) worker in a simple way by extending the class _ThreadWorker_:
 
 ```js
-'use strict'
-const { ThreadWorker } = require('poolifier')
+import { ThreadWorker } from 'poolifier'
 
-function yourFunction (data) {
+function yourFunction(data) {
   // this will be executed in the worker thread,
   // the data will be received by using the execute method
   return { ok: 1 }
 }
 
 module.exports = new ThreadWorker(yourFunction, {
-  maxInactiveTime: 60000,
-  async: false
+  maxInactiveTime: 60000
 })
 ```
 
-Instantiate your pool based on your needed :
+Instantiate your pool based on your needs :
 
 ```js
-'use strict'
-const { FixedThreadPool, DynamicThreadPool } = require('poolifier')
+import { DynamicThreadPool, FixedThreadPool, PoolEvents, availableParallelism } from 'poolifier'
 
-// a fixed worker-threads pool
-const pool = new FixedThreadPool(15,
-  './yourWorker.js',
-  { errorHandler: (e) => console.error(e), onlineHandler: () => console.log('worker is online') })
+// a fixed worker_threads pool
+const pool = new FixedThreadPool(availableParallelism(), './yourWorker.js', {
+  onlineHandler: () => console.info('worker is online'),
+  errorHandler: e => console.error(e)
+})
+
+pool.emitter?.on(PoolEvents.ready, () => console.info('Pool is ready'))
+pool.emitter?.on(PoolEvents.busy, () => console.info('Pool is busy'))
 
-// or a dynamic worker-threads pool
-const pool = new DynamicThreadPool(10, 100,
-  './yourWorker.js',
-  { errorHandler: (e) => console.error(e), onlineHandler: () => console.log('worker is online') })
+// or a dynamic worker_threads pool
+const pool = new DynamicThreadPool(Math.floor(availableParallelism() / 2), availableParallelism(), './yourWorker.js', {
+  onlineHandler: () => console.info('worker is online'),
+  errorHandler: e => console.error(e)
+})
 
-pool.emitter.on('FullPool', () => console.log('Pool is full'))
+pool.emitter?.on(PoolEvents.full, () => console.info('Pool is full'))
+pool.emitter?.on(PoolEvents.ready, () => console.info('Pool is ready'))
+pool.emitter?.on(PoolEvents.busy, () => console.info('Pool is busy'))
 
 // the execute method signature is the same for both implementations,
-// so you can easy switch from one to another
-pool.execute({}).then(res => {
-  console.log(res)
-}).catch ....
-
+// so you can easily switch from one to another
+pool
+  .execute()
+  .then(res => {
+    console.info(res)
+  })
+  .catch(err => {
+    console.error(err)
+  })
 ```
 
-You can do the same with the classes ClusterWorker, FixedClusterPool and DynamicClusterPool.
+You can do the same with the classes _ClusterWorker_, _FixedClusterPool_ and _DynamicClusterPool_.
 
-**See examples folder for more details (in particular if you want to use a pool for [multiple functions](./examples/multiFunctionExample.js)).**  
-**Now TypeScript is also supported, find how to use it into the example folder**.
+**See [examples](./examples/) for more details**:
 
-Remember that workers can only send and receive serializable data.
+- [Javascript](./examples/javascript/)
+- [Typescript](./examples/typescript/)
+  - [HTTP client pool](./examples/typescript/http-client-pool/)
+  - [SMTP client pool](./examples/typescript/smtp-client-pool/)
+  - [HTTP server pool](./examples/typescript/http-server-pool/)
+    - [Express worker_threads pool](./examples/typescript/http-server-pool/express-worker_threads/)
+    - [Express cluster pool](./examples/typescript/http-server-pool/express-cluster/)
+    - [Express hybrid pool](./examples/typescript/http-server-pool/express-hybrid/)
+    - [Fastify worker_threads pool](./examples/typescript/http-server-pool/fastify-worker_threads/)
+    - [Fastify cluster pool](./examples/typescript/http-server-pool/fastify-cluster/)
+    - [Fastify hybrid pool](./examples/typescript/http-server-pool/fastify-hybrid/)
+  - [WebSocket server pool](./examples/typescript/websocket-server-pool/)
+    - [ws worker_threads pool](./examples/typescript/websocket-server-pool/ws-worker_threads/)
+    - [ws cluster pool](./examples/typescript/websocket-server-pool/ws-cluster/)
+    - [ws hybrid pool](./examples/typescript/websocket-server-pool/ws-hybrid/)
 
-## Node versions
+Remember that workers can only send and receive structured-cloneable data.
 
-You can use node versions 12.x, 13.x, 14.x
+## Node.js versions
 
-## API
+Node.js versions >= 18.x.x are supported.
 
-### `pool = new FixedThreadPool/FixedClusterPool(numberOfThreads/numberOfWorkers, filePath, opts)`
+## [API](./docs/api.md)
 
-`numberOfThreads/numberOfWorkers` (mandatory) Num of workers for this worker pool  
-`filePath` (mandatory) Path to a file with a worker implementation  
-`opts` (optional) An object with these properties :
+## [General guidelines](./docs/general-guidelines.md)
 
-- `errorHandler` - A function that will listen for error event on each worker
-- `onlineHandler` - A function that will listen for online event on each worker
-- `exitHandler` - A function that will listen for exit event on each worker
-- `maxTasks` - This is just to avoid not useful warnings message, is used to set [maxListeners](https://nodejs.org/dist/latest-v12.x/docs/api/events.html#events_emitter_setmaxlisteners_n) on event emitters (workers are event emitters)
-
-### `pool = new DynamicThreadPool/DynamicClusterPool(min, max, filePath, opts)`
-
-`min` (mandatory) Same as FixedThreadPool/FixedClusterPool numberOfThreads/numberOfWorkers, this number of workers will be always active  
-`max` (mandatory) Max number of workers that this pool can contain, the new created workers will die after a threshold (default is 1 minute, you can override it in your worker implementation).  
-`filePath` (mandatory) Same as FixedThreadPool/FixedClusterPool  
-`opts` (optional) Same as FixedThreadPool/FixedClusterPool
-
-### `pool.execute(data)`
-
-Execute method is available on both pool implementations (return type : Promise):  
-`data` (mandatory) An object that you want to pass to your worker implementation
-
-### `pool.destroy()`
-
-Destroy method is available on both pool implementations.  
-This method will call the terminate method on each worker.
-
-### `class YourWorker extends ThreadWorker/ClusterWorker`
-
-`fn` (mandatory) The function that you want to execute on the worker  
-`opts` (optional) An object with these properties:
-
-- `maxInactiveTime` - Max time to wait tasks to work on (in ms), after this period the new worker will die.  
-  The last active time of your worker unit will be updated when a task is submitted to a worker or when a worker terminate a task.  
-  If `killBehavior` is set to `KillBehaviors.HARD` this value represents also the timeout for the tasks that you submit to the pool, when this timeout expires your tasks is interrupted and the worker is killed if is not part of the minimum size of the pool.  
-  If `killBehavior` is set to `KillBehaviors.SOFT` your tasks have no timeout and your workers will not be terminated until your task is completed.  
-  Default: 60.000 ms
-
-- `async` - true/false, true if your function contains async pieces else false
-- `killBehavior` - Dictates if your async unit (worker/process) will be deleted in case that a task is active on it.  
-  **SOFT**: If `currentTime - lastActiveTime` is greater than `maxInactiveTime` but a task is still running, then the worker **won't** be deleted.  
-  **HARD**: If `lastActiveTime` is greater than `maxInactiveTime` but a task is still running, then the worker will be deleted.  
-  This option only apply to the newly created workers.  
-  Default: `SOFT`
-
-## Choose your pool
-
-Performance is one of the main target of these worker pool implementations, we want to have a strong focus on this.  
-We already have a bench folder where you can find some comparisons.
-To choose your pool consider that with a FixedThreadPool/FixedClusterPool or a DynamicThreadPool/DynamicClusterPool (in this case is important the min parameter passed to the constructor) your application memory footprint will increase.  
-Increasing the memory footprint, your application will be ready to accept more CPU bound tasks, but during idle time your application will consume more memory.  
-One good choose from my point of view is to profile your application using Fixed/Dynamic worker pool, and to see your application metrics when you increase/decrease the num of workers.  
-For example you could keep the memory footprint low choosing a DynamicThreadPool/DynamicClusterPool with 5 workers, and allow to create new workers until 50/100 when needed, this is the advantage to use the DynamicThreadPool/DynamicClusterPool.  
-But in general, **always profile your application**
+## [Worker choice strategies](./docs/worker-choice-strategies.md)
 
 ## Contribute
 
-See guidelines [CONTRIBUTING](CONTRIBUTING.md)  
-Choose your task here [2.0.0](https://github.com/pioardi/poolifier/projects/1), propose an idea, a fix, an improvement.
+Choose your task [here](https://github.com/orgs/poolifier/projects/1), propose an idea, a fix, an improvement.
 
-## Team
+See [CONTRIBUTING](./CONTRIBUTING.md) guidelines.
 
-<!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section -->
-<!-- prettier-ignore-start -->
-<!-- markdownlint-disable -->
+## Team
 
 **Creator/Owner:**
 
 - [**Alessandro Pio Ardizio**](https://github.com/pioardi)
 
-**_Contributors_**
+**Maintainers:**
 
-- [**Shinigami92**](https://github.com/Shinigami92)
 - [**Jérôme Benoit**](https://github.com/jerome-benoit)
 
+**Contributors:**
+
+- [**Shinigami92**](https://github.com/Shinigami92)
+
 ## License
 
 [MIT](./LICENSE)