Sharded Akka Application (example)

A simple implementation of akka sharding. This is a simulation of Conveyor Sorting Subsystem.

This repository serves as a support for my live-coding talk. You can look at slides on speakerdeck. There is also a blog post that you can use as a guide to create your own version. Please visit Scalability using Sharding from Akka Cluster.

Measuring requests per second

You can test both applications on your local machine by using:

ab - Apache HTTP server benchmarking tool,
parallel - GNU Parallel - The Command-Line Power Tool,
haproxy - fast and reliable http reverse proxy and load balancer,
provided URLs.txt for single-noded app,
provided shardedURLs.txt and haproxy.conf.

Akka configuration is capped so that we can simulate different conditions on commodity laptop.

SingleNodedApp

Just run SingleNodedApp from your IDE or sbt runSingle and then:

cat src/main/resources/URLs.txt | parallel -j 5 'ab -ql -n 2000 -c 1 -k {}' | grep 'Requests per second'

ShardedApp

First build the application:

mvn clean package

This will build target/SortingDecider-1.0-SNAPSHOT-uber.jar. You will be able to run two nodes by overriding default values:

first node: java -jar target/SortingDecider-1.0-SNAPSHOT-uber.jar
second node: java -Dclustering.port=2552 -Dapplication.exposed-port=8081 -jar target/SortingDecider-1.0-SNAPSHOT-uber.jar

For benchmarking sharded application you need to use haproxy. Simple configuration for haproxy daemon can be found in resources dir. Run it with: ```haproxy -f src/main/resources/haproxy.conf````

This will set up a round-robing load balancer with frontend on port 8000 and backends on 8080 and 8081. You can then use different shardedURLs.txt file:

cat src/main/resources/shardedURLs.txt | parallel -j 5 'ab -ql -n 2000 -c 1 -k {}' | grep 'Requests per second'

Analysing results

To analyse results of requests per second measurements, please read Scalability Testing section in this blog post.

Notes