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Akka Rapid Benchmark

This benchmark environment allows to deploy Akka Clusters of arbitrary size. It has been used successfully in order to bootstrap a 10,000 node cluster as described in this article.

10000 nodes

It was developed primarily developed for use with the Rapid membership protocol integration of Akka Cluster, but can also be used to bootstrap a regular Akka Cluster.

Infrastructure setup

This project uses Terraform in order to deploy the infrastructure. See deploy/akka-cluster for details.

AWS EC2 limits

Depending on the size of the cluster you want to launch, request the appropriate limit increases. For example, for 10k:

  • Network interfaces: 10000
  • Running On-Demand All Standard (A, C, D, H, I, M, R, T, Z) instances: 40000

AWS API throttling limits

In order to bootstrap things faster, those would be nice to have (not sure if AWS will grant them to you though).

See the documentation

  • RunInstances Request Token bucket size: 1000, refill rate 100
  • DescribeInstances Request Token bucket size 1000, refill rate 100

Subnet / VPC setup

Make sure to create 3 subnets that are in the same region and copy their IDs for later.

Make sure that nothing prevents the subnets from communicating with each other, i.e. check the security group settings and other networking rules.

To the very least all 3 subnets need to be able to talk to each other via the ports configured in deploy/

Custom Terraform AWS provider

In order to speed up concurrency when creating the infrastructure via terraform, you can use this hack:

git clone
cd terraform-provider-aws
git checkout concurrency-hack
make tools
make build
  • run terraform init from the deploy directory of this directory to create the fitting directory structure
  • copy the resulting artifact from this custom build into the plugins subdirectory that works with your architecture, e.g. deploy/.terraform/plugins/linux_amd64.

Prioject setup instructions

Building Rapid

git clone
cd rapid
git checkout ch-broadcaster
mvn install

Building Akka

git clone
cd akka
git checkout rapid

Rebuilding Akka after a change

In order to have it tagged properly, you need to update the tag

git tag -d v2.6.4-SNAPSHOT
git add .
git commit -m "Change description"
git tag -a v2.6.4-SNAPSHOT -m "Rapid"

Generate an SSH key for the EC2 instances

Generate a key without passphrase, don't overwrite your default ssh key:

ssh-keygen -t rsa -b 2048 -v
Enter file in which to save the key: /tmp/akka
Enter passphrase (empty for no passphrase): Enter
Enter same passphrase again: Enter
Your identification has been saved in /tmp/akka.
Your public key has been saved in /tmp/
The key fingerprint is: ...

Convert it to PEM:

openssl rsa -in /tmp/akka -outform pem > /home/user/akka.pem

Add it to the SSH agent, useful to ssh into the instances:

ssh-add /home/user/akka.pem

Preparing the deployment script

Copy the script to script and fill in the necessary values.

In order to get logging support, you'll need an deployment.

Running an experiment

  • edit StartupCoordinator.scala if necessary and adjust the experimental setup parameters:
val InitialBatchSize = 500
val IncrementalBatchSize = 500
val SpareHostsLimit = 1500

val InitialBatchInterval = 25.seconds
val InitialProgressTimeout = 45.seconds
  • run the experiment
sh 100 0

This will launch a 100 node cluster with 0 broadcasters

Since the EC2 instances will be divided in groups of 3, you need to make sure that num instances - num broadcasters - 1 is divisible by 3.


sh 10000 102

For a 10000 node cluster with 102 broadcasters

Terminating instances

DO NOT FORGET TO DO THIS or else you'll pay for it (quite literally, with your money)

Using the Instance Terminator

You need to have the aws cli tools installed and all the necessary environment variables set for this to work

runMain io.bernhardt.akka.rapid.InstanceTerminator

Stopping instances from the seed node

You can ssh to the seed node and create the /tmp/akka-stop-all file in order to quickly instruct all registered instances to shut down.

Get the hostname of the seed node using:

runMain io.bernhardt.akka.rapid.SeedNodeAddress

Then run:

ssh ubuntu@ec2-...
echo "Stop" > /tmp/akka-stop-all

Note that this will only stop the instances, it won't terminate them, don't forget to run the terminator later on.

Plotting results

See the vega visualization in plotting/vega.txt in order to create a Vega visualzation in Kibana.

Running locally

  • comment out the bashExtraDefines in build.sbt
  • enable the console appender / disable the file appender in src/main/resources/logback.xml
  • run sh 50 to bootstrap a 50 nodes cluster on your machine. Make sure you have a strong machine

For reference, a 16 core AMD Threadripper with 64 GB of RAM can run clusters up to 200 nodes before it starts bursting into flames.


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