cmr-graph

A service and API for querying CMR metadata relationships

Contents

• About
• Documentation
  • Dependencies
  • Quick Start
  • Example Usage
  • Guides
  • Reference
• License

About ↟

This is an experimental project created as part of a 2-day Hackfest for improved relational data and discovery for NASA's Earthdata Search system. In particular, here we are exploring the use of graph databases and related indexing methodologies with the aim of helping users find out more about the Earth science data they care about.

Future explorations:

• Apache TinkerPop
• JanusGraph
• Clojure Ogre

A separate "CMR Recommend" service that utilizes the graph database service to identify data sets the Earthdata Search user may be interested in.

Documentation ↟

Dependencies ↟

• Java
• lein
• docker
• docker-compose

Note that your Docker installation needs have at least 4GB of memory allocate to it in order for Elasticsearch and Kibana to run.

Quick Start ↟

For an interactive environment:

$ lein start-infra

Note that Elasticsearch and Kibana used in this setup need 4GB of free space in Docker; be sure your settings have been updated to account for this.

Then, in another terminal:

$ lein repl

[cmr.graph.dev] λ=> (startup)

For a non-interactive environment:

$ lein start-infra

and:

$ lein start-cmr-graph

Ingesting Demo Data

If you want to exercise the movie demo portions of CMR Graph, you will need to ingest the movie data. In particular, once the infrastructure is up:

1. Visit the Neo4j web console at http://localhost:7474/browser/.
2. In the "Jump into code" box, click the "Write Code" button.
3. In the new section that appears at the top of the page, click the "Create a Graph" button in the "Movie Graph" box.
4. In the tutorial carousel that appears at the top of the page, click the right arrow.
5. In the next frame of the carousel, there is a little "play" button at the top left of the code (right before the first CREATE statement): click it.
6. A code section now appears at the top of the page with a "play" button at the far right: click it.

At this point, your instance of Neo4j should have the demo movie data.

Ingesting Collection Data

curl -i -XPOST http://localhost:3012/collections/import

Read More

Be sure to check out the "Guides" section below for links to more details on setup and use of CMR Graph.

Example Usage ↟

For a quick taste of using CMR Graph, we've put a snippet of JavaScript code below, using the experimental CMR Client. See the links in the "Guides" section below for links to more detailed examples and other usage.

var client = cmr.client.graph.create_client({"return-body?": true});
var channel = cmr.client.graph.get_collection_url_relation(
	client, "C1276812863-GES_DISC");
cmr.client.common.util.with_callback(channel, function(data) {
  var formatted_output = JSON.stringify(data, null, 2);
  document.getElementById("data").innerHTML = formatted_output;
});

This does require a running CMR Graph system (Neo4j + CMR Graph REST server; follow the instructions above to start them up). If you have everything running, you can make that call in your web developer tools JavaScript console at:

• http://localhost:3012/static/gui-demo/edsc.html

Project Guides ↟

• Setup
• Connecting to the Infrastructure
• Usage Examples
• Development Environment

Project Reference ↟

• API Reference
• Marginalia

Related Resources

• Neo4j Cypher cheatsheet
• Neo4j Manual: Cypher

License ↟

Copyright © 2018 NASA

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.