Évora

Évora is a research framework for service composition and orchestration in SDN-enabled environments.

Docker Environment

For research reproducibility, Évora provides a Dockerized environment for its core dependencies (ActiveMQ, Axis2, CXF).

Automated Startup

chmod +x evora.sh
./evora.sh

Tip

If you encounter Docker errors like KeyError: 'ContainerConfig', run the script with the clean flag: ./evora.sh --clean

The services will be available at:

• ActiveMQ (AMQP): localhost:61616 (or next free port)
• Axis2 (Legacy): localhost:8080 (or next free port)
• CXF (Modern): localhost:8081 (or next free port)

Note

Dynamic Port Resolution: The evora.sh script automatically detects port conflicts.

1. If the required port is occupied by the same service (e.g., from another project), it will reuse it.
2. If occupied by a different service, it assigns the next available port and automatically patches the Java source code and configuration files before building.

Framework Setup

Évora requires the Messaging4Transport middleware to be installed in your local Maven repository.

The evora.sh script handles everything automatically:

1. Verifies/installs Maven.
2. Auto-installs Messaging4Transport dependency if missing.
3. Manages Docker dependencies with dynamic port resolution.
4. Patches the framework and compiles the project.

chmod +x evora.sh
./evora.sh

Project Structure

• src/main/java/org/evora/core: Building block, composition, and Orchestration logic.
• src/main/java/org/evora/registry: Service Registry implementation.
• evora_topology.py: 12-node Mininet edge topology script.
• pom.xml: Configured with ODL repositories and messaging4transport-impl dependency.

Run the Benchmarker (after running ./evora.sh):

mvn exec:java -Dexec.mainClass="org.evora.core.util.Benchmarker"

Run Sample Orchestration:

mvn exec:java -Dexec.mainClass="org.evora.core.EvoraMain"

SDN Deployment (Mininet)

To spin up the 12-node edge topology in Mininet and connect it to the containerized OpenDaylight controller:

# Connect Mininet to the Dockerized ODL (listening on host port 6633)
sudo mn --custom evora_topology.py --topo evora --controller remote,ip=127.0.0.1,port=6633

Custom Simulation Inputs

To use your own topology and service chains, edit the configuration file:

• src/main/resources/input.json

The framework will automatically detect this file and load your custom nodes, link latencies, VNF placements, and orchestration policies.

Example input.json Schema:

{
  "topology": [{"id": "node1", "neighbors": ["node2"], "services": ["s1"], "cost": 10.0, "latency": 2.0, "throughput": 100.0}],
  "links": [{"from": "node1", "to": "node2", "latency": 5.0}],
  "serviceChain": ["s1", "s2"],
  "policy": {"costWeight": 1.0, "latencyWeight": 10.0, "throughputWeight": 1.0}
}

Citing Évora

If you use Évora in your research, please cite the following papers:

• Kathiravelu, P., Van Roy, P. and Veiga, L., 2018. Composing network service chains at the edge: A Resilient and adaptive software‐defined approach. Transactions on Emerging Telecommunications Technologies, 29(11), p.e3489.

• Kathiravelu, P., Grbac, T.G. and Veiga, L., 2016, June. Building blocks of Mayan: Componentizing the escience workflows through software-defined service composition. In 2016 IEEE International Conference on Web Services (ICWS) (pp. 372-379). IEEE.