Supplementary material for the paper: "Native Execution of GraphQL Queries over RDF Graphs Using Multi-way Joins"

Source code

• Tentris (graphql endpoint): https://github.com/dice-group/tentris/tree/graphql-endpoint
• Hypertrie (implementation of the multi-way left join algorithm): https://github.com/dice-group/hypertrie/tree/left-join

Experiments (Ansible playbook)

To set up the experiments we provide an Ansible playbook.

Installation: https://docs.ansible.com/ansible/latest/installation_guide/intro_installation.html

Before running the playbook

• Replace <ip_of_host> in ansible_playbook/inventory.yaml with the IP of the managed node (i.e., the server that will run the experiments).
• Replace <target_dir> in ansible_playbook/roles/base/defaults/main.yaml with the absolute path to the directory of the managed node that will store the experiments' required files.
• Replace <user> in ansible_playbook/roles/base/defaults/main.yaml with the username that will be used to login with to the managed node.
• Install docker in the server that will run the experiments (https://docs.docker.com/engine/install/debian/) (Note: The user must be added to the docker group)

Playbook Execution

You can execute the playbook by issuing the following command:

ansible-playbook -kKi inventory.yaml playbook.yaml

Benchmark Execution

Before running the benchmarks:

• increase ulimit

    ulimit -n 64000
  

• set swappiness to 0

    sudo sysctl vm.swappiness=0
  

• prepare neo4j databases

    cd <target_dir>
    sudo ./run_load_.sh
  

To run the benchmark execute the script run_graphql.sh with root privileges.

cd <target_dir>
sudo ./run_graphql.sh

The results of the benchmark (IGUANA result files) are stored in the directory <target_dir>/iguana_results/graphql

Datasets, Queries and Results

The datasets used in the benchmark, their respective queries and the GraphQL schemata are available for download here.

The results reported in the paper and the scripts to generate the plots are available for download here.

Pre-Built Binaries

The pre-built binary of our implementation is available for download here.