Point all Nodes to the Same Liferay DXP Database

Each node should have a data source that points to one Liferay DXP database (or a database cluster) that all the nodes share. This means, of course, Liferay DXP cannot (and should not) use the embedded HSQL database that is shipped with the bundles (but you already knew that, right?). And, of course, the database server should be on a separate system from the Liferay DXP server.

Read-Writer Database Configuration

For even better performance, you can also use a read-writer database configuration. This strategy uses two different data sources for reading and writing, so you can split your database infrastructure into two sets: one optimized for reading and one optimized for writing. Since all supported databases support replication, use your database vendor’s replication mechanism to keep the database nodes in sync.

Set up the databases for replication now.

Then enable a read-writer database in your portal-ext.properties file:

1. If you’re not using JNDI, set the default database connection pool provider to dbcp, tomcat, or c3po. Note, provider HikariCP does not support read/write splitting. Here’s an example setting:

   jdbc.default.liferay.pool.provider=dbcp
   

   All the portal JDBC configuration properties are documented here.

   Skip to step 3 to use JNDI.

2. Configure two different data sources, one for reading, and one for writing:

   jdbc.read.driverClassName=com.mysql.jdbc.Driver
   jdbc.read.url=jdbc:mysql://dbread.com/lportal?useUnicode=true&characterEncoding=UTF-8&useFastDateParsing=false
   jdbc.read.username=**your user name**
   jdbc.read.password=**your password**
   
   jdbc.write.driverClassName=com.mysql.jdbc.Driver
   jdbc.write.url=jdbc:mysql://dbreadwrite.com/lportal?useUnicode=true&characterEncoding=UTF-8&useFastDateParsing=false
   jdbc.write.username=**your user name**
   jdbc.write.password=**your password**
   

3. To use the JNDI instead of the JDBC data sources, set the *.username and *.password properties from step 2 to your JNDI user name and password and set these additional properties:

   jdbc.read.jndi.name=**your read JNDI name**
   jdbc.write.jndi.name=**your read-write JNDI name**
   

4. Avoid using the default data source, by setting this:

   counter.jdbc.prefix=jdbc.write.
   

   And if you’re using a dbcp or tomcat database connection pool provider, set these:

   jdbc.default.validationQuery=
   jdbc.read.validationQuery=SELECT releaseId FROM Release_
   jdbc.write.validationQuery=SELECT releaseId FROM Release_
   

   These settings are related to issue LPS-64624.

5. Enable the read-writer database configuration by uncommenting the following Spring configuration files from the spring.configs and spring.infrastructure.configs properties:

   spring.configs=\
       [..]
       META-INF/dynamic-data-source-spring.xml,\
       [..]
   
   spring.infrastructure.configs=\
       [..]
       META-INF/dynamic-data-source-infrastructure-spring.xml,\
       [..]
   

   The Spring configuration portal properties are documented here.

The next time you start Liferay DXP, it uses the two data sources you have defined.