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Quick Start

Install Nebula Graph

From Docker

The easiest way to get Nebula Graph up and running is using Docker. Before you start, make sure that you have:

  • Installed the latest version of Docker

  • Pulled the latest images of Nebula from Nebula Docker Hub. If not, pull the images using the following command:

> docker pull vesoft/nebula-graph:latest

Startup Nebula Graph

When nebula image is ready, run a container:

> docker run -it vesoft/nebula-graph:latest /bin/bash

After login, you're in the root directory and you should switch to the nebula directory

> cd /usr/local/nebula/

Start meta service, storage service and graph service:

> scripts/nebula.service start all

Check services' status:

> scripts/nebula.service status all

Connect to Nebula Graph

connect to Nebula:

> bin/nebula -u=user -p=password
  • -u is to set the user name, user is the default Nebula user account
  • -p is to set password, password is the default password for account user

If you have any questions or concerns about the deployment procedures, please do not hesitate to open an issue on GitHub.

From Source(Linux)

Prerequisite Tools

Nebula Graph is written in C++14, so it requires a compiler supporting C++14 features.

3rd-party Libraries

  • autoconf
  • automake
  • libtool
  • cmake
  • bison
  • unzip
  • boost
  • gperf
  • krb5
  • openssl
  • libunwind
  • ncurses
  • readline
  • flex

It is recommended to install g++ 5 or higher Linux system, such as Fedora 29. Currently, we are using git-lfs to store the 3rd-party libraries so make sure git-lfs have been installed before fetching the source code.

Fetch from GitHub

> git clone https://github.com/vesoft-inc/nebula.git

Compiling

> cmake ./

The default installation is in /usr/local path. To specify the installation path, use:

> cmake -DCMAKE_INSTALL_PREFIX=$your_nebula_install_dir

to replace the $your_nebula_install_dir here

Then run the following command:

> make && make install

Running

  • Configure nebula-metad.conf

    In your Nebula installation directory, run

    > cp etc/nebula-metad.conf.default etc/nebula-metad.conf

    Modify configurations in nebula-metad.conf:

    • local_ip
    • port
    • ws_http_port: metaservice HTTP port
    • ws_h2_port: metaservice HTTP2 port

  • Configure nebula-storaged.conf

    > cp etc/nebula-storaged.conf.default etc/nebula-storaged.conf

    Modify configurations in nebula-storaged.conf:

    • local_ip
    • port
    • ws_http_port: storageservice HTTP port
    • ws_h2_port: storageservice HTTP2 port

  • Configure nebula-graphd.conf

    > cp etc/nebula-graphd.conf.default etc/nebula-graphd.conf

    Modify configurations in nebula-graphd.conf:

    • local_ip
    • port
    • ws_http_port: graphservice HTTP port
    • ws_h2_port: graphservice HTTP2 port

Start Service

> scripts/nebula.service start all

Make sure all the services are working

> scripts/nebula.service status all

Connect to Nebula Graph

> bin/nebula -u=user -p=password
  • -u is to set the user name, user is the default Nebula user account
  • -p is to set password, password is the default password for account user

Then you’re now ready to start using Nebula Graph.

Build Your Own Graph

This section describes how to build a graph and run queries. The example is built on the graph below:

Untitled Diagram (1)

There are three kinds of tags (course, building and student) and two edge types (select and like). The graph schema is:

{  
   "tags":{  
      "course":[  
         "name: string",
         "credits: integer"
      ],
      "building":[  
         "name: string"
      ],
      "student":[  
         "name: string",
         "age: integer",
         "gender: string"
      ]
   },
   "edges":{  
      "select":[  
         "grade: integer"
      ],
      "like":[  
         "likeness: double"
      ]
   }
}

Create a Graph Space

SPACE is a region that provides physically isolation of graphs in Nebula. First, we need to create a space and use it before other operations.

To list all existing spaces:

nebula> SHOW SPACES;

To create a new space named myspace_test2 :

nebula> CREATE SPACE myspace_test2(partition_num=1, replica_factor=1);

-- Use this space
nebula> USE myspace_test2;

  • replica_factor specifies the number of replicas in the cluster.

  • partition_num specifies the number of partitions in one replica.

Define Graph Schema

The CREATE TAG statement defines a tag, with a type name and an attribute list.

nebula> CREATE TAG course(name string, credits int);
nebula> CREATE TAG building(name string);
nebula> CREATE TAG student(name string, age int, gender string);

The CREATE EDGE statement defines an edge type.

nebula> CREATE EDGE like(likeness double);
nebula> CREATE EDGE select(grade int);

To list the tags and edge types that we just created：

-- Show tag list
nebula> SHOW TAGS;

-- Show edge type list
nebula> SHOW EDGES;

To show the attributes of a tag or an edge type:

-- Show attributes of a tag
nebula> DESCRIBE TAG student;

-- Show attributes of an edge type
nebula> DESCRIBE EDGE like;

Insert Data

Insert the vertices and edges based on the graph above.

-- Insert vertices
nebula> INSERT VERTEX student(name, age, gender) VALUES 200:("Monica", 16, "female");
nebula> INSERT VERTEX student(name, age, gender) VALUES 201:("Mike", 18, "male");
nebula> INSERT VERTEX student(name, age, gender) VALUES 202:("Jane", 17, "female");
nebula> INSERT VERTEX course(name, credits),building(name) VALUES 101:("Math", 3, "No5");
nebula> INSERT VERTEX course(name, credits),building(name) VALUES 102:("English", 6, "No11");

-- Insert edges
nebula> INSERT EDGE select(grade) VALUES 200 -> 101:(5);
nebula> INSERT EDGE select(grade) VALUES 200 -> 102:(3);
nebula> INSERT EDGE select(grade) VALUES 201 -> 102:(3);
nebula> INSERT EDGE select(grade) VALUES 202 -> 102:(3);
nebula> INSERT EDGE like(likeness) VALUES 200 -> 201:(92.5);
nebula> INSERT EDGE like(likeness) VALUES 201 -> 200:(85.6);
nebula> INSERT EDGE like(likeness) VALUES 201 -> 202:(93.2);

Sample Queries

Q1. Find the vertexes that 201 likes:

nebula> GO FROM 201 OVER like;

=======
|  id |
=======
| 200 |
-------
| 202 |
-------

Q2. Find the vertexes that 201 likes, whose ages are greater than 17. Return their name, age and gender, and alias the columns as Friend, Age and Gender, respectively.

nebula> GO FROM 201 OVER like WHERE $$.student.age >= 17 YIELD $$.student.name AS Friend, $$.student.age AS Age, $$.student.gender AS Gender;

=========================
| Friend | Age | Gender |
=========================
|   Jane |  17 | female |
-------------------------

YIELD specifies what values or results you might want to return from query.

$^ represents the source vertex.

$$ indicates the target vertex.

Q3. Find the selected courses and corresponding grades of students liked by 201.

-- By pipe
nebula> GO FROM 201 OVER like | GO FROM $-.id OVER select YIELD $^.student.name AS Student, $$.course.name AS Course, select.grade AS Grade;

=============================
| Student |  Course | Grade |
=============================
|  Monica |    Math |     5 |
-----------------------------
|  Monica | English |     3 |
-----------------------------
|    Jane | English |     3 |
-----------------------------

-- By temporary variable
nebula> $a=GO FROM 201 OVER like; GO FROM $a.id OVER select YIELD $^.student.name AS Student, $$.course.name AS Course, select.grade AS Grade;

=============================
| Student |  Course | Grade |
=============================
|  Monica |    Math |     5 |
-----------------------------
|  Monica | English |     3 |
-----------------------------
|    Jane | English |     3 |
-----------------------------

| denotes a pipe. The output of the formal query acts as input to the next one like a pipeline.

$- refers to the input stream.

The second approach adopts a user-defined variable $a. The scope of this variable is within the compound statement.

For more details about Query Language, check nGQL Query Language.