MultiGraph Overview

1
Mo
EM
Last updated last month

Version 1.2 to 2.0 Copyright © 2018 TigerGraph. All Rights Reserved . For technical support on this topic, contact support@tigergraph.com with a subject line beginning with "multiple graphs"

Beginning with Version 1.2, one TigerGraph instance can manage multiple graphs, each with its own set of user privileges. This first-of-its-kind capability, dubbed MultiGraph, is available as an optional service in the Enterprise Edition of the TigerGraph platform. MultiGraph enables several powerful use cases:

  • Multiple Tenancy : Use one TigerGraph instance to support several completely separate data sets, each with its own set of users. Each user community is unaware of the other user communities or other data sets.

  • Fine-grained privileges on the same set of data : Role-based access control, available on single graphs, grants permission for the privilege to run queries (include data modification queries). In a single graph scheme, there is not a way to say "Query X can be run by some users but not by others." Using multiple graphs defined over the same set of data, each graph can have its own set of queries and own set of users, in effect customizing who can run which queries.

  • Overlapping graphs : Graphs can partially overlap, to enable a combination of shared and private data.

  • Hierarchical subgraphs : A Graph X can be defined to cover the domains of Graphs Y and Z, that is, Graph X = (Graph Y) U (Graph Z). This provides an interesting way to describe a data partitioning or parent-child structure. (This is not the same as defining sub-classes of data types; data types are still independent.)

If you implement only one graph now, you can upgrade to MultiGraph and add additional graphs at any time, without having to redo your existing design.

While the system has the inherent capability of managing multiple graphs, the ability of users to create more than one graph may depend on your license key.

To support the new MultiGraph capabilities, a few changes to the previous specifications are necessary. These changes affect all users, even if only a single graph is deployed. We advise all users to read the Concepts and Modified Specifications below.

There are also several New Commands .

Concepts

Graphs and Graph Domains

A graph is a defined as a set of vertex types and edge types. More precisely, it is all the vertices and edges of that collection of types. The domain of a graph is its set of vertex types and edge types.

CREATE GRAPH <gname> (<list of vertex types and edge types>)

NEW

  • It is possible to define multiple graphs. The domains of two graphs may be completely separate, may overlap, or may coincide exactly.

  • A TigerGraph instance with a basic license key can have one graph. A TigerGraph instance with a MultiGraph license key can create multiple graphs.

  • A vertex type or edge type created by a superuser is a global type.

  • A superuser can include a global vertex or edge type in one or more graphs. Global types can be shared among multiple graphs.

  • The admin users or designer users for a particular graph can add local vertex types and edge types to their own graph.

Graph-Specific Roles and Privileges

The TigerGraph system includes several predefined roles. Each role is a fixed and logical set of privileges to perform operations. In order to access a graph, a user must be granted a role on that graph. Without a role, a user has no meaningful access.

CHANGES

  • User roles are granted or revoked on a per-graph basis . Each GRANT or REVOKE statement specifies not only a role but also a graph.

  • A user may be granted different roles on different graphs .

  • A new top-level role is added: superuser . The superuser automatically has admin privilege on every graph, and has additional global privileges.

Setting a Working Graph

Previously, there was only one graph, and so all users were automatically able to use that graph.

NEW

  • A user must set their working graph in order to access that graph.

  • Users who have privileges on more than one graph (including superusers) may only work with one graph at a time. The GLOBAL SCHEMA_CHANGE JOB stretches this rule.

Note that the CREATE commands for queries, loading jobs, and schema_change jobs have always required that the graph name be specified, even when there was support for only one graph. Now, it is clear that these definitions are graph-specific.

New and Modified Specifications

Modified Specifications

If you are a user of an earlier TigerGraph system (v1.1 or earlier), please note the following specifications have changed.

  1. Set the working graph in GSQL: You must always set the working graph, either using the -g flag with the gsql command, or by using the USE GRAPH command.

  2. RESTPP Endpoint changes: Endpoints which pertain to the graph data have been modified to include the name of the graph in the request URL. See RESTPP API User Guide .

  3. User Authentication secrets and tokens: The way in which secrets and tokens are created and used has changed, in order to follow OAuth standards more closely. See Managing User Privileges and Authentication.

  4. Changes to privileges of certain roles: If you had been using only the single default user with admin privilege, you will not notice any difference. That user has been promoted to superuser status. If you are making use of users with different roles, note the following changes in privileges:

    • A new top-level role, superuser , is defined. The superuser has admin privilege on all graphs, and is the only role who can create and modify shared vertex types, shared edge types, and graphs.

    • The architect role is renamed designer .

    • The public role is renamed observer .

    • The following commands are now shifted from admin and designer roles to the superuser role:

      • CREATE / DROP VERTEX|EDGE|GRAPH

      • CLEAR GRAPH STORE

      • DROP ALL

    • Newly created users no longer automatically have the observer role. They have no role until explicitly granted one.

  5. In the CREATE VERTEX statement, the WITH STATS option "outdegree" is no longer available. "outdegree_by_edgetype" is still supported and is the default.

There are many other details about using the MultiGraph feature, especially if your application has multiple users with different roles. In the documentation, the Multiple Graph logo is placed next to relevant topics:

New Commands

The following commands are new. This section provides only a summary list. For full details and examples, see the main documentation for the relevant topics.

USE GRAPH <graph_name>

  • For all users

  • Sets the given graph as the user's working graph.

USE GLOBAL

  • For superusers

  • Must be set to have privilege to create and assign global vertex and edge types.

CREATE GLOBAL SCHEMA_CHANGE JOB

  • For superusers