schema.md

How to Deploy your own Schema

Gaffer uses schema files to describe the data contained in a Graph. This guide will tell you how to deploy your own schemas with a Gaffer Graph.

The first thing you'll need to do is deploy a simple graph. We have a guide for how to do that here.

Once you have that deployed, we can change the schema.

Edit the schema

If you run a GetSchema operation against the graph, you'll notice that the count property is of type java.lang.Integer. Let's change that property to be of type java.lang.Long.

The easiest way to deploy a schema file is to use helm's --set-file option which lets you set a value from the contents of a file. So if you had a schema.json file containing:

{
  "edges": {
    "BasicEdge": {
      "source": "vertex",
      "destination": "vertex",
      "directed": "true",
      "properties": {
          "count": "count"
      }
    }
  },
  "entities": {
    "BasicEntity": {
      "vertex": "vertex",
      "properties": {
          "count": "count"
      }
    }
  },
  "types": {
    "vertex": {
      "class": "java.lang.String"
    },
    "count": {
      "class": "java.lang.Long",
      "aggregateFunction": {
          "class": "uk.gov.gchq.koryphe.impl.binaryoperator.Sum"
      }
    },
    "true": {
      "description": "A simple boolean that must always be true.",
      "class": "java.lang.Boolean",
      "validateFunctions": [
          { "class": "uk.gov.gchq.koryphe.impl.predicate.IsTrue" }
      ]
    }
  }
}

Update deployment with the new schema

For our deployment to pick up the changes, we need to run a helm upgrade:

helm upgrade my-graph gaffer-docker/gaffer --set-file graph.schema."schema\.json"=./schema.json --reuse-values

The --reuse-values argument tells helm to re-use the passwords that we defined earlier.

Now if we inspect the schema, you'll see that the count property has changed to a Long.

What next?

See our guides for other things you can do with Gaffer on Kubernetes.