Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/seantanly/elixir-paratize

Elixir library providing some handy parallel processing facilities that supports configuring number of workers and timeout.
https://github.com/seantanly/elixir-paratize

elixir-library parallel-processing

Last synced: 8 days ago
JSON representation

Elixir library providing some handy parallel processing facilities that supports configuring number of workers and timeout.

Awesome Lists containing this project

README 

        
Paratize

========

[![Build Status](https://travis-ci.org/seantanly/elixir-paratize.svg?branch=master)](https://travis-ci.org/seantanly/elixir-paratize)

[![Hex.pm Version](http://img.shields.io/hexpm/v/paratize.svg?style=flat)](https://hex.pm/packages/paratize)



Elixir library providing some handy parallel processing facilities that supports configuring number of workers and timeout.



This library is inspired by [Parex](https://github.com/StevenJL/parex).



## Documentation



API documentation is available at [http://hexdocs.pm/paratize](http://hexdocs.pm/paratize)



## Adding Paratize To Your Project



To use Paratize with your projects, edit your `mix.exs` file and add it as a dependency:



```elixir

defp deps do

  [

    {:paratize, "~> x.x.x"},

  ]

end

```



## Examples



Paratize is designed to run slow tasks in parallel. There are two processor implementatons, first the chunk based implementation `Paratize.Chunk` and the second the worker pool based implementation `Paratize.Pool`. Both modules have the same API.



* `parallel_exec(fun_list, task_options)`

* `parallel_map(arg_list, fun, task_options)`

* `parallel_each(arg_list, fun, task_options)`



To execute a list of functions in parallel,



```elixir

import Paratize.Pool



function_list = [

  fn -> Math.fib(40) end,

  fn -> :timer.sleep(5000) end,

  fn -> HTTPotion.get("http://wwww.reddit.com") end

]



parallel_exec(function_list) # => [102334155, :ok, %HTTPotion.Response{body...}]



function_keyword_list = [

  fib: fn -> Math.fib(40) end,

  hang: fn -> :timer.sleep(5000) end,

  web_request: fn -> HTTPotion.get("http://wwww.reddit.com") end

]



parallel_exec(function_keyword_list) # => [fib: 102334155, hang: :ok, web_request: %HTTPotion.Response{body...}]



```



To execute a `map` in parallel,  

(useful when results are needed for further processing)



```elixir

import Paratize.Pool



slow_func = fn arg -> :timer.sleep(1000); arg + 1 end

workload = 1..100



{time, result} = :timer.tc fn -> workload |> parallel_map(slow_func) |> Enum.join(", ") end

time # => 13034452 (8 CPU cores system, running 8 workers)

```



To execute a `each` in parallel,  

(useful when resultset is large, and can be processed individually to prevent memory hog)



```elixir

import Paratize.Pool



lots_of_urls |> parallel_each(fn url ->

  HTTPotion.get(url) |> parse_page |> save_meta_data

end)



```



## Task Options



Each function accepts task options to customize the parallel processing.



* size - the number of parallel workers, defaults to the number of system cores given by `:erlang.system_info(:schedulers)`

* timeout - in milliseconds, the *minimum* time given for a function to complete, defaults to `5000`. If timeout happens, the entire parallel processing crashes with `exit(:timeout,...)`. To disable timeout, use `:infinity`.



## Considerations



To achieve maximum parallelism, `%Paratize.TaskOptions{}` size should be set to size of your workload,



```elixir

alias Paratize.Pool



slow_func = fn arg -> :timer.sleep(1000); arg + 1 end

workload = 1..100



{time, result} = :timer.tc fn ->

    workload |> Pool.parallel_map(slow_func, size: Enum.count(workload)) |> Enum.join(", ")

end

time # => 1004370 (Running 100 workers)



```



The `%Paratize.TaskOptions{}` `timeout` should not be relied upon for precise timing out of each workload, because it is not strictly enforced. It is an implementation detail that *reasonably* crashes the processor if no further work is completed after the timeout period has lapsed.



## LICENSE



This software is licensed under [MIT LICENSE](LICENSE.md).