Installing the Data Catalog on a Cluster: Sharing the Same Settings Across All the Nodes

This section explains how to configure the Data Catalog to store its settings on an external database.

By default, the Data Catalog stores the global settings and certain settings for each user in a local database. For example, the user “Saved Queries”, the fields selected by the administrator to display by default on a view search, etc.

If you installed Denodo on a cluster and there is an Data Catalog installed on each node of the cluster, you can configure all of them to store and retrieve these settings from a common database. Otherwise, users will use different settings depending on the node the load balancer redirects them.

Important

The Data Catalog makes use of web sessions, so when it is installed on a cluster, the load balancer should be configured to redirect all the request of the same web session to the same node (sticky sessions).

Setting Up the Common Database

Before configuring the Data Catalog you should create and configure the common database in which all the tools of the cluster will store the common settings. You can use the DBMS of your choice. You have to:

  1. Install the DBMS (if not installed yet).
  2. Create the database to be used by the Data Catalog. An existent database could be used but it is recommended to create a new one to avoid possible conflicts with the table names.
  3. Configure a user (and its password) with create, read and write privileges on that database.

Configure the Data Catalog to Use the Common Database

Clustering works by having each node of the cluster share the same database. To enable this feature you have to configure each Data Catalog of the cluster to use the common database.

This process involves stopping the Denodo web container in each node (i.e. all the SOAP and REST web services and web administration tools will be stopped for a few seconds).