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Kollaps: Decentralized Container Based Network Emulator

This README is a quick introduction to get up and running with Kollaps and Thunderstorm. Kollaps is the decentralized network emulator while Thunderstorm is the high-level language to specify experiments. Kollaps currently only functions in machines with the Native Linux Kernel (minimium version:5.15.0) due to the usage of both eBPF and Linux traffic control.

Deployments over WLS will not work due to technical limitations on WSL itself.


For extra documentation on how to use Kollaps you can check our website.

Contact Us

If you want to discuss or have problems using Kollaps, we have a discord channel, join us here.

Quick Start

The easier way to get up and running with Kollaps is to clone the project, build the docker images, and run experiments locally in a docker swarm.

When checking out the code, make sure you install the submodules as well:

git clone --branch master --depth 1 --recurse-submodules
cd Kollaps

Then build the docker images:

docker build --rm -f dockerfiles/Kollaps -t kollaps:2.0 .
docker build -f dockerfiles/DeploymentGenerator -t kollaps-deployment-generator:2.0 .

Initialise the swarm and create an overlay network:

docker swarm init
docker network create --driver=overlay --subnet= kollaps_network

For topologies with more then 257 services use:

docker network create --driver=overlay --subnet= kollaps_network

Lastly run a simple experiment:

# Create topology file and experiment images
cd examples
./KollapsDeploymentGenerator ./iperf3/topology.xml -s topology.yaml
./KollapsAppBuilder iperf3

# Deploy experiment
docker stack deploy -c topology.yaml kollaps_example

# Open a browser and navigate to
# Click `start` when all experiments are `ready`

# Remove the experiment
docker stack rm kollaps_example

Cite the work

You may want to check the paper describing the system in detail which appeared in EUROSYS'20. Or cite it:

  author = {Gouveia, Paulo and Neves, Jo\~{a}o and Segarra, Carlos and Liechti, Luca and Issa, Shady and Schiavoni, Valerio and Matos, Miguel},
  title = {Kollaps: Decentralized and Dynamic Topology Emulation},
  year = {2020},
  isbn = {9781450368827},
  publisher = {Association for Computing Machinery},
  address = {New York, NY, USA},
  url = {},
  doi = {10.1145/3342195.3387540},
  booktitle = {Proceedings of the Fifteenth European Conference on Computer Systems},
  articleno = {Article 23},
  numpages = {16},
  keywords = {emulation, dynamic network topology, experimental reproducibility, distributed systems, containers},
  location = {Heraklion, Greece},
  series = {EuroSys ’20}