Moreover you can execute your tasks using an API designed to improve the **developer experience**.
Please consult our [general guidelines](#general-guidance).
-- Performance :racehorse: [benchmarks](./benchmarks/README.md)
-- Security :bank: :cop: [](https://sonarcloud.io/dashboard?id=pioardi_poolifier) [](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
-- Easy to use :couple:
+- Easy to use :white_check_mark:
+- Performance [benchmarks](./benchmarks/README.md) :white_check_mark:
- Dynamic pool size :white_check_mark:
- Easy switch from a pool to another :white_check_mark:
- No runtime dependencies :white_check_mark:
- Proper async integration with node async hooks :white_check_mark:
-- Support for worker threads and cluster node modules :white_check_mark:
+- Support CommonJS, ESM, and TypeScript :white_check_mark:
+- Support for worker-threads and cluster node modules :white_check_mark:
- Support sync and async tasks :white_check_mark:
- Tasks distribution strategies :white_check_mark:
-- General guidance on pools to use :white_check_mark:
+- General guidance on pool choice :white_check_mark:
- Widely tested :white_check_mark:
- Error handling out of the box :white_check_mark:
- Active community :white_check_mark:
-- Code quality :octocat: [](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
+- Code quality [](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
[](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
[](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
[](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
[](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
[](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
+- Code security [](https://sonarcloud.io/dashboard?id=pioardi_poolifier) [](https://sonarcloud.io/dashboard?id=pioardi_poolifier)
## Contents
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.
+You have to implement your worker by extending the ThreadWorker or ClusterWorker class.
## Installation
```js
'use strict'
-const { DynamicThreadPool, FixedThreadPool, PoolEvents } = require('poolifier')
+const { DynamicThreadPool, FixedThreadPool, PoolEvents, availableParallelism } = require('poolifier')
// a fixed worker-threads pool
-const pool = new FixedThreadPool(15,
- './yourWorker.js',
- { errorHandler: (e) => console.error(e), onlineHandler: () => console.log('worker is online') })
+const pool = new FixedThreadPool(availableParallelism(), './yourWorker.js', {
+ errorHandler: e => console.error(e),
+ onlineHandler: () => console.info('worker is online')
+})
-pool.emitter.on(PoolEvents.busy, () => console.log('Pool is busy'))
+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') })
+const pool = new DynamicThreadPool(Math.floor(availableParallelism() / 2), availableParallelism(), './yourWorker.js', {
+ errorHandler: e => console.error(e),
+ onlineHandler: () => console.info('worker is online')
+})
-pool.emitter.on(PoolEvents.full, () => console.log('Pool is full'))
-pool.emitter.on(PoolEvents.busy, () => console.log('Pool is busy'))
+pool.emitter.on(PoolEvents.full, () => console.info('Pool is full'))
+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 ....
-
+pool
+ .execute({})
+ .then(res => {
+ console.info(res)
+ })
+ .catch(err => {
+ console.error(err)
+ })
```
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 with [multiple worker functions](./examples/multiFunctionExample.js))**.
+**See [examples](./examples/) folder for more details (in particular if you want to use a pool with [multiple worker functions](./examples/multiFunctionExample.js))**.
-Remember that workers can only send and receive serializable data.
+Remember that workers can only send and receive structured-cloneable data.
## Node versions
## [API](https://poolifier.github.io/poolifier/)
-### `pool = new FixedThreadPool/FixedClusterPool(numberOfThreads/numberOfWorkers, filePath, opts)`
+### `PoolOptions`
-`numberOfThreads/numberOfWorkers` (mandatory) Number of workers for this pool
-`filePath` (mandatory) Path to a file with a worker implementation
-`opts` (optional) An object with these properties:
+An object with these properties:
- `messageHandler` (optional) - A function that will listen for message event on each worker
- `errorHandler` (optional) - A function that will listen for error event on each worker
- `exitHandler` (optional) - A function that will listen for exit event on each worker
- `workerChoiceStrategy` (optional) - The worker choice strategy to use in this pool:
- - `WorkerChoiceStrategies.ROUND_ROBIN`: Submit tasks to worker in a round robbin fashion
- - `WorkerChoiceStrategies.LEAST_USED`: Submit tasks to the worker with the minimum number of running and ran tasks
- - `WorkerChoiceStrategies.LEAST_BUSY`: Submit tasks to the worker with the minimum tasks total execution time
- - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN`: Submit tasks to worker using a weighted round robin scheduling algorithm based on tasks execution time
- - `WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN`: Submit tasks to worker using an interleaved weighted round robin scheduling algorithm based on tasks execution time (experimental)
- - `WorkerChoiceStrategies.FAIR_SHARE`: Submit tasks to worker using a fair share tasks scheduling algorithm based on tasks execution time
+ - `WorkerChoiceStrategies.ROUND_ROBIN`: Submit tasks to worker in a round robin fashion
+ - `WorkerChoiceStrategies.LEAST_USED`: Submit tasks to the worker with the minimum number of executed, executing and queued tasks
+ - `WorkerChoiceStrategies.LEAST_BUSY`: Submit tasks to the worker with the minimum tasks total execution and wait time
+ - `WorkerChoiceStrategies.LEAST_ELU`: Submit tasks to the worker with the minimum event loop utilization (ELU) (experimental)
+ - `WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN`: Submit tasks to worker by using a [weighted round robin scheduling algorithm](./src/pools/selection-strategies/README.md#weighted-round-robin) based on tasks execution time
+ - `WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN`: Submit tasks to worker by using an [interleaved weighted round robin scheduling algorithm](./src/pools/selection-strategies/README.md#interleaved-weighted-round-robin) based on tasks execution time(experimental)
+ - `WorkerChoiceStrategies.FAIR_SHARE`: Submit tasks to worker by using a [fair share scheduling algorithm](./src/pools/selection-strategies/README.md#fair-share) based on tasks execution time (the default) or ELU active time
`WorkerChoiceStrategies.WEIGHTED_ROUND_ROBIN`, `WorkerChoiceStrategies.INTERLEAVED_WEIGHTED_ROUND_ROBIN` and `WorkerChoiceStrategies.FAIR_SHARE` strategies are targeted to heavy and long tasks.
Default: `WorkerChoiceStrategies.ROUND_ROBIN`
- `workerChoiceStrategyOptions` (optional) - The worker choice strategy options object to use in this pool.
Properties:
- - `medRunTime` (optional) - Use the tasks median runtime instead of the tasks average runtime in worker choice strategies.
- - `weights` (optional) - The worker weights to use in the weighted round robin worker choice strategy: `{ 0: 200, 1: 300, ..., n: 100 }`
+ - `measurement` (optional) - The measurement to use in worker choice strategies: `runTime`, `waitTime` or `elu`.
+ - `runTime` (optional) - Use the tasks [median](./src/pools/selection-strategies/README.md#median) runtime instead of the tasks average runtime in worker choice strategies.
+ - `waitTime` (optional) - Use the tasks [median](./src/pools/selection-strategies/README.md#median) wait time instead of the tasks average wait time in worker choice strategies.
+ - `elu` (optional) - Use the tasks [median](./src/pools/selection-strategies/README.md#median) ELU instead of the tasks average ELU in worker choice strategies.
+ - `weights` (optional) - The worker weights to use in weighted round robin worker choice strategies: `{ 0: 200, 1: 300, ..., n: 100 }`.
- Default: `{ medRunTime: false }`
+ Default: `{ runTime: { median: false }, waitTime: { median: false }, elu: { median: false } }`
- `restartWorkerOnError` (optional) - Restart worker on uncaught error in this pool.
- Default: true
+ Default: `true`
- `enableEvents` (optional) - Events emission enablement in this pool.
- Default: true
+ Default: `true`
- `enableTasksQueue` (optional) - Tasks queue per worker enablement in this pool.
- Default: false
+ Default: `false`
- `tasksQueueOptions` (optional) - The worker tasks queue options object to use in this pool.
Properties:
Default: `{ concurrency: 1 }`
+#### `ThreadPoolOptions extends PoolOptions`
+
+- `workerOptions` (optional) - An object with the worker options to pass to worker. See [worker_threads](https://nodejs.org/api/worker_threads.html#worker_threads_new_worker_filename_options) for more details.
+
+#### `ClusterPoolOptions extends PoolOptions`
+
+- `env` (optional) - An object with the environment variables to pass to worker. See [cluster](https://nodejs.org/api/cluster.html#cluster_cluster_fork_env) for more details.
+
+- `settings` (optional) - An object with the cluster settings. See [cluster](https://nodejs.org/api/cluster.html#cluster_cluster_settings) for more details.
+
+### `pool = new FixedThreadPool/FixedClusterPool(numberOfThreads/numberOfWorkers, filePath, opts)`
+
+`numberOfThreads/numberOfWorkers` (mandatory) Number of workers for this pool
+`filePath` (mandatory) Path to a file with a worker implementation
+`opts` (optional) An object with the pool options properties described above
+
### `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
+`filePath` (mandatory) Path to a file with a worker implementation
+`opts` (optional) An object with the pool options properties described above
-### `pool.execute(data)`
+### `pool.execute(data, name)`
`data` (optional) An object that you want to pass to your worker implementation
+`name` (optional) A string with the task function name that you want to execute on the worker. Default: `'default'`
This method is available on both pool implementations and returns a promise.
### `pool.destroy()`
### `class YourWorker extends ThreadWorker/ClusterWorker`
-`taskFunctions` (mandatory) The task function(s) that you want to execute on the worker
+`taskFunctions` (mandatory) The task function or task functions object that you want to execute on the worker
`opts` (optional) An object with these properties:
- `maxInactiveTime` (optional) - Max time to wait tasks to work on in milliseconds, 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.HARD` this value represents also the timeout for the tasks that you submit to the pool, when this timeout expires your tasks is interrupted before completion and removed. 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: 60000
+ Default: `60000`
- `killBehavior` (optional) - Dictates if your async unit (worker/process) will be deleted in case that a task is active on it.
- **KillBehaviors.SOFT**: If `currentTime - lastActiveTime` is greater than `maxInactiveTime` but a task is still running, then the worker **won't** be deleted.
- **KillBehaviors.HARD**: If `currentTime - lastActiveTime` is greater than `maxInactiveTime` but a task is still running, then the worker will be deleted.
+ **KillBehaviors.SOFT**: If `currentTime - lastActiveTime` is greater than `maxInactiveTime` but a task is still executing or queued, then the worker **won't** be deleted.
+ **KillBehaviors.HARD**: If `currentTime - lastActiveTime` is greater than `maxInactiveTime` but a task is still executing or queued, then the worker will be deleted.
This option only apply to the newly created workers.
Default: `KillBehaviors.SOFT`
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 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.
+One good choice from poolifier team point of view is to profile your application using fixed or 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**.
## Contribute
-Choose your task here [2.5.x](https://github.com/orgs/poolifier/projects/1), propose an idea, a fix, an improvement.
+Choose your task here [2.6.x](https://github.com/orgs/poolifier/projects/1), propose an idea, a fix, an improvement.
See [CONTRIBUTING](CONTRIBUTING.md) guidelines.
## Team
-<!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section -->
-
**Creator/Owner:**
- [**Alessandro Pio Ardizio**](https://github.com/pioardi)
repositories / poolifier.git / blobdiff