JBR Experiment - WatDiv

A jbr experiment type for the Waterloo SPARQL Diversity Test Suite (WatDiv).

Requirements

• Node.js (1.12 or higher)
• Docker (required for invoking WatDiv Docker)
• jbr (required for initializing, preparing, and running experiments on the command line)

Quick start

1. Install jbr

jbr is a command line tool that enables experiments to be initialized, prepared, and started. It can be installed from the npm registry:

$ npm install -g jbr

or

$ yarn global add jbr

2. Initialize a new experiment

Using the jbr CLI tool, initialize a new experiment:

$ jbr init watdiv my-experiment
$ cd my-experiment

This will create a new my-experiment directory with default configs for this experiment type.

3. Configure the required hooks

This experiment type requires you to configure a certain SPARQL endpoint to send queries to for the hookSparqlEndpoint. A value for this hook can be set as follows, such as sparql-endpoint-comunica:

$ jbr set-hook hookSparqlEndpoint sparql-endpoint-comunica

4. Prepare the experiment

In order to run all preprocessing steps, such as creating all required datasets, invoke the prepare step:

$ jbr prepare

All prepared files will be contained in the generated/ directory:

generated/
  dataset.hdt
  dataset.hdt.index.v1-1
  dataset.nt
  queries/

5. Run the experiment

Once the experiment has been fully configured and prepared, you can run it:

$ jbr run

Once the run step completes, results will be present in the output/ directory.

Output

The following output is generated after an experiment has run.

output/query-times.csv:

name;id;results;time;timestamps
interactive-short-4;0;0;7;
interactive-short-4;1;0;5;
interactive-short-4;2;0;6;
interactive-short-4;3;0;3;
interactive-short-4;4;0;3;
interactive-short-5;0;0;0;
interactive-short-5;1;0;0;
interactive-short-5;2;0;0;
interactive-short-5;3;0;0;
interactive-short-5;4;0;0;

Configuration

The default generated configuration file (jbr-experiment.json) for this experiment looks as follows:

{
  "@context": [
    "https://linkedsoftwaredependencies.org/bundles/npm/jbr/^2.0.0/components/context.jsonld",
    "https://linkedsoftwaredependencies.org/bundles/npm/@jbr-experiment/watdiv/^1.0.0/components/context.jsonld"
  ],
  "@id": "urn:jrb:test-watdiv2",
  "@type": "ExperimentWatDiv",
  "datasetScale": 1,
  "queryCount": 5,
  "queryRecurrence": 1,
  "generateHdt": true,
  "endpointUrl": "http://localhost:3001/sparql",
  "queryRunnerReplication": 3,
  "queryRunnerWarmupRounds": 1,
  "queryRunnerRecordTimestamps": true,
  "queryRunnerUrlParamsInit": {},
  "queryRunnerUrlParamsRun": {},
  "hookSparqlEndpoint": {
    "@id": "urn:jrb:test-watdiv2:hookSparqlEndpoint",
    "@type": "HookNonConfigured"
  }
}

Any config changes require re-running the prepare step.

More background information on these config options can be found in the README of WatDiv Docker.

Configuration fields

• datasetScale: Scale factor (1 ~= 100K triples), defaults to 1.
• queryCount: Query count per type.
• queryRecurrence: Query recurrence factor.
• generateHdt: If a dataset.hdt should also be generated.
• endpointUrl: URL through which the SPARQL endpoint of the hookSparqlEndpoint hook will be exposed.
• endpointUrlExternal: URL through which the SPARQL endpoint of the hookSparqlEndpoint hook will be exposed. This will be used for waiting until the endpoint is available.
• queryRunnerReplication: Number of replication runs for sparql-benchmark-runner.
• queryRunnerWarmupRounds: Number of warmup runs for sparql-benchmark-runner.
• queryRunnerRecordTimestamps: Flag to indicate if result arrival timestamps must be recorded by sparql-benchmark-runner.
• queryRunnerRecordHttpRequests: Flag to indicate if the number of http requests must be reported by sparql-benchmark-runner.
• queryRunnerUrlParamsInit: A JSON record of string mappings containing URL parameters that will be passed to the SPARQL endpoint during initialization to check if the endpoint is up.
• queryRunnerUrlParamsRun: A JSON record of string mappings containing URL parameters that will be passed to the SPARQL endpoint during query executions.
• queryTimeoutFallback: An optional timeout value for a single query in milliseconds, to be used as fallback in case the SPARQL endpoint hook's timeout fails. This should always be higher than the timeout value configured in the SPARQL endpoint hook.

License

jbr.js is written by Ruben Taelman.

This code is copyrighted by Ghent University – imec and released under the MIT license.