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
930
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
200
Fun with Elixir Macros
teamon
1
420
Elixir - Bydgoszcz Web Development Meetup
teamon
2
720
Sidekiq
teamon
1
140
Git - Monterail style
teamon
1
150
Rails Assets wroc_love.rb
teamon
1
680
Angular replacements for jQuery-based libraries
teamon
1
290
Angular replacements for jQuery-based libraries
teamon
2
290
Rails Assets LRUG
teamon
0
7.4k
Other Decks in Programming
See All in Programming
Запуск 1С:УХ в крупном энтерпрайзе: мечта и реальность ПМа
lamodatech
0
930
Fibonacci Function Gallery - Part 2
philipschwarz
PRO
0
210
Jaspr Dart Web Framework 박제창 @Devfest 2024
itsmedreamwalker
0
150
KMP와 kotlinx.rpc로 서버와 클라이언트 동기화
kwakeuijin
0
290
iOS開発におけるCopilot For XcodeとCode Completion / copilot for xcode
fuyan777
1
1.4k
サーバーゆる勉強会 DBMS の仕組み編
kj455
1
300
はてなにおけるfujiwara-wareの活用やecspressoのCI/CD構成 / Fujiwara Tech Conference 2025
cohalz
2
2.3k
ISUCON14感想戦で85万点まで頑張ってみた
ponyo877
1
570
今年のアップデートで振り返るCDKセキュリティのシフトレフト/2024-cdk-security-shift-left
tomoki10
0
360
CQRS+ES の力を使って効果を感じる / Feel the effects of using the power of CQRS+ES
seike460
PRO
0
240
AIレシート読み取り機能をRuby on Rails on AWSで実現するLLMにまつわるアレコレ / AI-based receipt reading function powered by LLM on Ruby on Rails on AWS
moznion
3
120
shadcn/uiを使ってReactでの開発を加速させよう!
lef237
0
290
Featured
See All Featured
Refactoring Trust on Your Teams (GOTO; Chicago 2020)
rmw
33
2.7k
Intergalactic Javascript Robots from Outer Space
tanoku
270
27k
Fireside Chat
paigeccino
34
3.1k
Building Adaptive Systems
keathley
38
2.4k
Side Projects
sachag
452
42k
The MySQL Ecosystem @ GitHub 2015
samlambert
250
12k
The Pragmatic Product Professional
lauravandoore
32
6.4k
Designing for humans not robots
tammielis
250
25k
Statistics for Hackers
jakevdp
797
220k
RailsConf 2023
tenderlove
29
970
Building a Scalable Design System with Sketch
lauravandoore
460
33k
Building an army of robots
kneath
302
45k
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?