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Version: 0.7.0-incubating

How to use relational backend storage

Introduction​

Before the version 0.6.0-incubating, Apache Gravitino supports KV and Relational backend storage to store metadata. Since 0.6.0-incubating, Gravitino only supports using RDBMS as relational backend storage to store metadata. This doc will guide you on how to use the relational backend storage in Gravitino.

Relational backend storage mainly aims to the users who are accustomed to using RDBMS to store data or lack available a KV storage, and want to use Gravitino.

With relational backend storage, you can quickly deploy Gravitino in a production environment and take advantage of relational storage to manage metadata.

What kind of backend storage is supported​

Currently, relational backend storage supports the JDBCBackend, and H2, MySQL and PostgreSQL are supported currently for JDBCBackend, H2 is the default storage for JDBCBackend.

How to use H2​

As mentioned above, H2 is the default storage for JDBCBackend, so you can use H2 directly without any additional configuration.

How to use MySQL​

Prerequisites​

  • MySQL 5.7 or 8.0.
  • Gravitino distribution package.
  • MySQL connector Jar (Should be compatible with the version of MySQL instance).

Step 1: Get the initialization script​

You need to download and unzip the distribution package firstly, please see How to install Gravitino.

Then you can get the initialization script in the directory:

${GRAVITINO_HOME}/scripts/mysql/

The script name is like schema-{version}-mysql.sql, and the version depends on your Gravitino version. For example, if your Gravitino version is 0.6.0-incubating, then you can choose the latest version script. If you used a legacy script, you can use upgrade-{old version}-to-{new version}-mysql.sql to upgrade the schema.

Step 2: Initialize the database​

Please create a database in MySQL in advance, and execute the initialization script obtained above in the database.

Step 3: Place the MySQL connector Jar​

You should download the MySQL connector Jar for the corresponding version of MySQL you use (You can download it from the maven-central-repo), which is name like mysql-connector-java-{version}.jar.

Then please place it in the distribution package directory:

${GRAVITINO_HOME}/libs/

Step 4: Set up the Apache Gravitino server configs​

Find the server configuration file which name is gravitino.conf in the distribution package directory:

${GRAVITINO_HOME}/conf/

Then set up the following server configs:

gravitino.entity.store = relational
gravitino.entity.store.relational = JDBCBackend
gravitino.entity.store.relational.jdbcUrl = ${your_jdbc_url}
gravitino.entity.store.relational.jdbcDriver = ${your_driver_name}
gravitino.entity.store.relational.jdbcUser = ${your_username}
gravitino.entity.store.relational.jdbcPassword = ${your_password}

Step 5: Start the server​

Finally, you can run the script in the distribution package directory to start the server:

./${GRAVITINO_HOME}/bin/gravitino.sh start

How to use PostgreSQL​

Prerequisites​

  • PostgreSQL 12 ~ 16. For other versions, the community has not tested fully and may not be compatible.
  • Gravitino distribution package with version 0.7.0 or above.
  • PostgreSQL connector Jar (Should be compatible with the version of PostgreSQL instance).

Step 1: Get the initialization script​

You need to download and unzip the distribution package firstly, please see How to install Gravitino.

Then you can get the initialization script in the directory:

${GRAVITINO_HOME}/scripts/postgresql/

The script name is like schema-{version}-postgresql.sql, and the version depends on your Gravitino version. For example, if your Gravitino version is the latest release version, then you can choose the latest version script. If you used a legacy script, you can use upgrade-{old version}-to-{new version}-postgresql.sql to upgrade the schema.

Step 2: Initialize the database​

Please create a database and schema in PostgreSQL in advance, and execute the initialization script obtained above in the database.

psql --username=postgres --password 
password:

create database your_database;
\c your_database
create schema your_schema;
set search_path to your_schema;
\i schema-{version}-postgresql.sql
note

Database and schema are required parameters in the Gravitino PostgreSQL JDBC URL, Users should create them in advance and set the database and schema in the JDBC URL.

Step 3: Place the PostgreSQL connector Jar​

You should download the PostgreSQL connector Jar for the corresponding version of PostgreSQL you use (You can download it from the PostgreSQL-driver-jar), which is name like postgresql-{version}.jar.

Then please place it in the distribution package directory:

${GRAVITINO_HOME}/libs/

Step 4: Set up the Apache Gravitino server configs​

Find the server configuration file which name is gravitino.conf in the distribution package directory:

${GRAVITINO_HOME}/conf/

Then set up the following server configs:

gravitino.entity.store = relational
gravitino.entity.store.relational = JDBCBackend

## JDBC URL such as: jdbc:postgresql://localhost:5432/your_database?currentSchema=your_schema
gravitino.entity.store.relational.jdbcUrl = ${your_jdbc_url}

## JDBC driver name such as: org.postgresql.Driver
gravitino.entity.store.relational.jdbcDriver = ${your_driver_name}

gravitino.entity.store.relational.jdbcUser = ${your_username}
gravitino.entity.store.relational.jdbcPassword = ${your_password}

Step 5: Start the server​

Please see the above steps in the MySQL section.