Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Elixir GenStage & Flow
Search
Tymon Tobolski
May 26, 2017
Programming
2
1k
Elixir GenStage & Flow
Poznań Elixir Meetup, 25.05.2017
Tymon Tobolski
May 26, 2017
Tweet
Share
More Decks by Tymon Tobolski
See All by Tymon Tobolski
Only possible with Elixir - ubots Case Study
teamon
0
250
Fun with Elixir Macros
teamon
1
490
Elixir - Bydgoszcz Web Development Meetup
teamon
2
860
Sidekiq
teamon
1
160
Git - Monterail style
teamon
1
180
Rails Assets wroc_love.rb
teamon
1
730
Angular replacements for jQuery-based libraries
teamon
1
350
Angular replacements for jQuery-based libraries
teamon
2
320
Rails Assets LRUG
teamon
0
7.5k
Other Decks in Programming
See All in Programming
Cursorハンズオン実践!
eltociear
2
1.2k
AIと人間の共創開発!OSSで試行錯誤した開発スタイル
mae616
2
780
pnpm に provenance のダウングレード を検出する PR を出してみた
ryo_manba
1
150
Six and a half ridiculous things to do with Quarkus
hollycummins
0
210
CSC305 Lecture 08
javiergs
PRO
0
270
Introduce Hono CLI
yusukebe
6
3k
Catch Up: Go Style Guide Update
andpad
0
240
組込みだけじゃない!TinyGo で始める無料クラウド開発入門
otakakot
2
360
CSC509 Lecture 07
javiergs
PRO
0
240
EMこそClaude Codeでコード調査しよう
shibayu36
0
340
Developer Joy - The New Paradigm
hollycummins
1
340
iOSでSVG画像を扱う
kishikawakatsumi
0
160
Featured
See All Featured
実際に使うSQLの書き方 徹底解説 / pgcon21j-tutorial
soudai
PRO
190
55k
The Art of Delivering Value - GDevCon NA Keynote
reverentgeek
16
1.7k
Side Projects
sachag
455
43k
Fashionably flexible responsive web design (full day workshop)
malarkey
407
66k
Making the Leap to Tech Lead
cromwellryan
135
9.6k
Build your cross-platform service in a week with App Engine
jlugia
232
18k
Facilitating Awesome Meetings
lara
57
6.6k
Learning to Love Humans: Emotional Interface Design
aarron
274
41k
Being A Developer After 40
akosma
91
590k
A Modern Web Designer's Workflow
chriscoyier
697
190k
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
kevinliebholz
36
6.1k
Statistics for Hackers
jakevdp
799
220k
Transcript
GenStage & Flow Poznań Elixir Meetup 25.05.2017
None
Hi! Tymon Tobolski • GitHub: teamon • Twitter: @iteamon •
Blog: teamon.eu • 8+ years with Ruby, 2+ years with Elixir • Currently Elixir+Dev+Ops @ Recruitee.com • Hex: tesla, mix_docker
None
The Job
Library defmodule Poz do def select do items = Enum.to_list
(1..100) :timer.sleep(:rand.uniform(100)) Progress.incr(:select, length(items)) items end def download(record) do :timer.sleep(:rand.uniform(100)) Progress.incr(:download) {:file, record} end
Library cont. def extract(file) do :timer.sleep(:rand.uniform(10)) Progress.incr(:extract) {:text, file} end
def index(texts) do :timer.sleep(:rand.uniform(1000)) Progress.incr(:index, length(texts)) :ok end end
Example blueprint defmodule Example do import Poz def run do
Progress.start_link([:select, :download, :extract, :index]) # work work work Progress.stop() end end
Example 1 - Enum select() |> Enum.map(&download/1) |> Enum.map(&extract/1) |>
index()
Example 1 - Enum
Example 2 - Stream select() |> Stream.concat([]) |> Stream.map(&download/1) |>
Stream.map(&extract/1) |> Enum.to_list() |> index()
Example 2 - Stream
Example 3 - Task.async select() |> Enum.map(fn e -> Task.async(Poz,
:download, [e]) end) |> Enum.map(&Task.await/1) |> Enum.map(fn e -> Task.async(Poz, :extract, [e]) end) |> Enum.map(&Task.await/1) |> index()
Example 3 - Task.async
Stages
GenStage explained
Example 4 - GenStage - SELECT defmodule Select do use
GenStage def init(_), do: {:producer, :ok} def handle_demand(demand, :ok) do items = Poz.select() {:noreply, items, :empty} end def handle_demand(_demand, :empty) do {:noreply, [], :empty} end end
Example 4 - GenStage - DOWNLOAD defmodule Download do use
GenStage def init(_), do: {:producer_consumer, :ok} def handle_events(items, _from, state) do files = Enum.map(items, &Poz.download/1) {:noreply, files, state} end end
Example 4 - GenStage - EXTRACT defmodule Extract do use
GenStage def init(_), do: {:producer_consumer, :ok} def handle_events(files, _from, state) do texts = Enum.map(files, &Poz.extract/1) {:noreply, files, texts} end end
Example 4 - GenStage - INDEX defmodule Index do use
GenStage def init(_), do: {:consumer, :ok} def handle_events(texts, _from, state) do Poz.index(texts) {:noreply, [], state} end end
Example 4 - GenStage {:ok, select} = GenStage.start_link(Select, :ok) {:ok,
download} = GenStage.start_link(Download, :ok) {:ok, extract} = GenStage.start_link(Extract, :ok) {:ok, index} = GenStage.start_link(Index, :ok) GenStage.sync_subscribe(download, to: select) GenStage.sync_subscribe(extract, to: download) GenStage.sync_subscribe(index, to: extract) :timer.sleep(:infinity)
Example 4 - GenStage (defaults)
Example 5 - GenStage (custom demand) {:ok, select} = GenStage.start_link(Select,
:ok) {:ok, download} = GenStage.start_link(Download, :ok) {:ok, extract} = GenStage.start_link(Extract, :ok) {:ok, index} = GenStage.start_link(Index, :ok) GenStage.sync_subscribe(download, to: select, max_demand: 20) GenStage.sync_subscribe(extract, to: download, max_demand: 20) GenStage.sync_subscribe(index, to: extract, max_demand: 100) :timer.sleep(:infinity)
Example 5 - GenStage (tuned demand)
Example 6 - GenStage (multiprocess) {:ok, select} = GenStage.start_link(Select, :ok)
{:ok, extract} = GenStage.start_link(Extract, :ok) {:ok, index} = GenStage.start_link(Index, :ok) for i <- (1..10) do {:ok, download} = GenStage.start_link(Download, i) GenStage.sync_subscribe(download, to: select, max_demand: 20) GenStage.sync_subscribe(extract, to: download, max_demand: 20) end GenStage.sync_subscribe(index, to: extract, max_demand: 100)
None
Example 7 - Flow select() |> Flow.from_enumerable(max_demand: 20) |> Flow.partition(max_demand:
20, stages: 5) |> Flow.map(&download/1) |> Flow.partition(max_demand: 20, stages: 2) |> Flow.map(&extract/1) |> Flow.partition(window: Flow.Window.count(50), stages: 1) |> Flow.reduce(fn -> [] end, fn item, list -> [item | list] end) |> Flow.emit(:state) |> Flow.partition(stages: 2) |> Flow.map(&index/1) |> Flow.run()
Example 7 - Flow
Real World
Real World - optimised
References • https:/ /github.com/teamon/poz • https:/ /elixir-lang.org/blog/2016/07/14/announcing-genstage/ • https:/ /hexdocs.pm/gen_stage/GenStage.html
• https:/ /hexdocs.pm/flow/Flow.html • http:/ /teamon.eu/2016/tuning-elixir-genstage-flow-pipeline- processing/ • http:/ /teamon.eu/2016/measuring-visualizing-genstage-flow- with-gnuplot/
Thanks! Questions?