Getting started with SmartGraphs

SmartGraphs cannot use existing collections. When switching to SmartGraph from an existing dataset you have to import the data into a fresh SmartGraph.

All collections that are being used in SmartGraphs need to be part of the same distributeShardslike group. The smartGraphAttribute and the number of shards are immutable. The smartGraphAttribute attribute is used to inform the database how to shard data and, as a consequence, all vertices must have this attribute. The _from and _to attributes that point from one document to another document stored in vertex collections are set by default, following the same smart sharding pattern.

Create a SmartGraph using the web interface

The web interface (also called Web UI) allows you to easily create and manage SmartGraphs. To get started, follow the steps outlined below.

1. In the web interface, navigate to the GRAPHS section.
2. To add a new graph, click Add Graph.
3. In the Create Graph dialog that appears, select the SmartGraph tab.
4. Fill in all the following fields:
   • For Name, enter a name for the SmartGraph.
   • For Shards, enter the number of parts to split the graph into.
   • Optional: For Replication factor, enter the total number of desired copies of the data in the cluster.
   • Optional: For Write concern, enter the total number of copies of the data in the cluster required for each write operation.
   • For SmartGraph Attribute, insert the attribute that is used to smartly shard the vertices of the graph. Every vertex in your graph needs to have this attribute. Note that it cannot be modified later.
   • Optional: For SatelliteCollections, insert vertex collections that are used in your edge definitions. These collections are then created as satellites, and thus replicated to all DB-Servers.
5. Define the relations on the graph:
   • For Edge definition, insert a single non-existent name to define the relation of the graph. This automatically creates a new edge collection, which is displayed in the COLLECTIONS section of the left sidebar menu.
     To define multiple relations, press the Add relation button. To remove a relation, press the Remove relation button.
   • For fromCollections, insert a list of vertex collections that contain the start vertices of the relation.
   • For toCollections, insert a list of vertex collections that contain the end vertices of the relation.
     Insert only non-existent collection names. Collections are automatically created during the graph setup and are displayed in the Collections tab of the left sidebar menu.
   • For Orphan collections, insert a list of vertex collections that are part of the graph but not used in any edge definition.
6. Click Create.
7. Click the card of the newly created graph and use the functions of the Graph Viewer to visually interact with the graph and manage the graph data.

Create a SmartGraph using arangosh

In contrast to General Graphs we have to add more options when creating the SmartGraph. The two options smartGraphAttribute and numberOfShards are required and cannot be modified later.

var graph_module = require("@arangodb/smart-graph");
var graph = graph_module._create("myGraph", [], [], {smartGraphAttribute: "region", numberOfShards: 9});
graph;

{[SmartGraph] 
}

Create a Disjoint SmartGraph using arangosh

In contrast to regular SmartGraphs we have to add one option when creating the graph. The boolean option isDisjoint is required, needs to be set to true and cannot be modified later.

var graph_module = require("@arangodb/smart-graph");
var graph = graph_module._create("myGraph", [], [], {smartGraphAttribute: "region", numberOfShards: 9, isDisjoint: true});
graph;

{[SmartGraph] 
}

Add vertex collections

This is analogous to General Graphs. Unlike with General Graphs, the collections must not exist when creating the SmartGraph. The SmartGraph module will create them for you automatically to set up the sharding for all these collections correctly. If you create collections via the SmartGraph module and remove them from the graph definition, then you may re-add them without trouble however, as they will have the correct sharding.

graph._addVertexCollection("shop");
graph._addVertexCollection("customer");
graph._addVertexCollection("pet");
graph = graph_module._graph("myGraph");

{[SmartGraph] 
  "customer" : [ArangoCollection 6011066, "customer" (type document, status loaded)], 
  "pet" : [ArangoCollection 6011077, "pet" (type document, status loaded)], 
  "shop" : [ArangoCollection 6011055, "shop" (type document, status loaded)] 
}

Define relations on the Graph

Adding edge collections works the same as with General Graphs, but again, the collections are created by the SmartGraph module to set up sharding correctly so they must not exist when creating the SmartGraph (unless they have the correct sharding already).

var rel = graph_module._relation("isCustomer", ["shop"], ["customer"]);
graph._extendEdgeDefinitions(rel);
graph = graph_module._graph("myGraph");

{[SmartGraph] 
  "isCustomer" : [ArangoCollection 6011132, "isCustomer" (type edge, status loaded)], 
  "shop" : [ArangoCollection 6011098, "shop" (type document, status loaded)], 
  "customer" : [ArangoCollection 6011109, "customer" (type document, status loaded)], 
  "pet" : [ArangoCollection 6011120, "pet" (type document, status loaded)] 
}

Using SatelliteCollections in SmartGraphs

When creating a collection, you can decide whether it’s a SatelliteCollection or not. For example, a vertex collection can be satellite as well. SatelliteCollections don’t require sharding as the data will be distributed globally on all DB-Servers. The smartGraphAttribute is also not required.

Create a SmartGraph using SatelliteCollections

In addition to the attributes you would set to create a SmartGraph, there is an additional attribute satellites you can optionally set. It needs to be an array of one or more collection names. These names can be used in edge definitions (relations) and these collections will be created as SatelliteCollections. However, all vertex collections on one side of the relation have to be of the same type - either all satellite or all smart. This is because _from and _to can have different types based on the sharding pattern.

In this example, both vertex collections are created as SatelliteCollections.

var graph_module = require("@arangodb/smart-graph");
var rel = graph_module._relation("isCustomer", "shop", "customer")
var graph = graph_module._create("myGraph", [rel], [], {satellites: ["shop", "customer"], smartGraphAttribute: "region", numberOfShards: 9});
graph;

{[SmartGraph] 
  "isCustomer" : [ArangoCollection 6011176, "isCustomer" (type edge, status loaded)], 
  "shop" : [ArangoCollection 6011174, "shop" (type document, status loaded)], 
  "customer" : [ArangoCollection 6011175, "customer" (type document, status loaded)] 
}

Create a Disjoint SmartGraph using SatelliteCollections

The option isDisjoint needs to be set to true in addition to the other options for a SmartGraph using SatelliteCollections. Only the shop vertex collection is created as a SatelliteCollection in this example:

var graph_module = require("@arangodb/smart-graph");
var rel = graph_module._relation("isCustomer", "shop", "customer")
var graph = graph_module._create("myGraph", [rel], [], {satellites: ["shop"], smartGraphAttribute: "region", isDisjoint: true, numberOfShards: 9});
graph;

{[SmartGraph] 
  "isCustomer" : [ArangoCollection 6011199, "isCustomer" (type edge, status loaded)], 
  "shop" : [ArangoCollection 6011198, "shop" (type document, status loaded)], 
  "customer" : [ArangoCollection 6011188, "customer" (type document, status loaded)] 
}