Table of Contents

MySQL Metadata Store

To use this Apache Druid (incubating) extension, make sure to include mysql-metadata-storage as an extension.

The MySQL extension requires the MySQL Connector/J library which is not included in the Druid distribution. Refer to the following section for instructions on how to install this library.

Installing the MySQL connector library

This extension uses Oracle's MySQL JDBC driver which is not included in the Druid distribution and must be installed separately. There are a few ways to obtain this library:

  • It can be downloaded from the MySQL site at:
  • It can be fetched from Maven Central at:
  • It may be available through your package manager, e.g. as libmysql-java on APT for a Debian-based OS

This should fetch a JAR file named similar to 'mysql-connector-java-x.x.xx.jar'.

Copy or symlink this file to extensions/mysql-metadata-storage under the distribution root directory.

Setting up MySQL

  1. Install MySQL

Use your favorite package manager to install mysql, e.g.: - on Ubuntu/Debian using apt apt-get install mysql-server - on OS X, using Homebrew brew install mysql

Alternatively, download and follow installation instructions for MySQL Community Server here:

  1. Create a druid database and user

Connect to MySQL from the machine where it is installed.

  > mysql -u root

Paste the following snippet into the mysql prompt:

  -- create a druid database, make sure to use utf8mb4 as encoding

  -- create a druid user
  CREATE USER 'druid'@'localhost' IDENTIFIED BY 'diurd';

  -- grant the user all the permissions on the database we just created
  GRANT ALL PRIVILEGES ON druid.* TO 'druid'@'localhost';
  1. Configure your Druid metadata storage extension:

Add the following parameters to your Druid configuration, replacing <host> with the location (host name and port) of the database.


Encrypting MySQL connections

This extension provides support for encrypting MySQL connections. To get more information about encrypting MySQL connections using TLS/SSL in general, please refer to this guide.


Property Description Default Required
druid.metadata.mysql.ssl.useSSL Enable SSL false no
druid.metadata.mysql.ssl.clientCertificateKeyStoreUrl The file path URL to the client certificate key store. none no
druid.metadata.mysql.ssl.clientCertificateKeyStoreType The type of the key store where the client certificate is stored. none no
druid.metadata.mysql.ssl.clientCertificateKeyStorePassword The Password Provider or String password for the client key store. none no
druid.metadata.mysql.ssl.verifyServerCertificate Enables server certificate verification. false no
druid.metadata.mysql.ssl.trustCertificateKeyStoreUrl The file path to the trusted root certificate key store. Default trust store provided by MySQL yes if verifyServerCertificate is set to true and a custom trust store is used
druid.metadata.mysql.ssl.trustCertificateKeyStoreType The type of the key store where trusted root certificates are stored. JKS yes if verifyServerCertificate is set to true and keystore type is not JKS
druid.metadata.mysql.ssl.trustCertificateKeyStorePassword The Password Provider or String password for the trust store. none yes if verifyServerCertificate is set to true and password is not null
druid.metadata.mysql.ssl.enabledSSLCipherSuites Overrides the existing cipher suites with these cipher suites. none no
druid.metadata.mysql.ssl.enabledTLSProtocols Overrides the TLS protocols with these protocols. none no