Configure the Virtual DataPort Servers¶

In the “Servers Configuration” tab you configure the Virtual DataPort servers that are listed in the login dialog.

If you add/modify a server, its URL has to contain a database, which will be used to authenticate the users.

From this section you can add, edit and delete the servers.

Servers Configuration: adding a new server¶

Configure the Connection Settings to the Virtual DataPort Servers¶

You can also configure the following global parameters of the connections created to execute queries against the Virtual DataPort Servers:

• Query timeout: maximum time (in milliseconds) that the query will wait for the statement to be completed. If not indicated (or the value 0 is received), then it waits until execution is complete (by default 900000).

• Chunk timeout: maximum time (in milliseconds) that the query will wait until it arrives a new chunk of results. Where this time is exceeded, Virtual DataPort returns the results extracted up to that moment. If not specified (or the value 0 is received), Virtual DataPort returns all the results together at the end of the statement run (by default 90000).

• Chunk size: number of results that make up a chunk of results. When Virtual DataPort Tool obtains this number of results, it will return them to the Data Catalog, even though the Chunk Timeout has not been reached (by default 1000).

Servers Configuration: connection settings to the Virtual DataPort servers¶

Use an External Database for the Data Catalog¶

The Data Catalog of the Denodo Platform includes an embedded database (Apache Derby). The Data Catalog stores the settings and metadata (description of views set by users of Data Catalog, properties, etc.) in this database.

You can configure the Data Catalog to store the metadata on an external database. This is necessary if you want to set up a cluster of Data Catalog servers.

This feature supports the following databases:

• MySQL 5.6 and 5.7: to use MySQL, make sure that MySQL - or the database in MySQL you are going to use - is configured with the options “Default Charset = utf8” and “Collation = utf8_unicode_ci”.

• Oracle 12c

• PostgreSQL 9.5

• SQL Server 2014

• Amazon Aurora for MySQL 5.7 and PostgreSQL 9.5

Follow these steps to store the metadata of the Data Catalog on an external database.

1. In the target database, create a catalog or a schema for the metadata of the Data Catalog. Although you can use an existing schema, we suggest creating one to keep the tables separate from the tables of other applications.

   We suggest reserving 5 gigabytes of space for this schema. In most cases, less space will be required. However, we recommend a high value to avoid issues due to the lack of space in the database.

2. Copy the JDBC driver of this database to the directory <DENODO_HOME>/lib/data-catalog-extensions

   To use Oracle 12, only copy the files ojdbc6.jar and orai18n.jar from <DENODO_HOME>/lib/extensions/jdbc-drivers/oracle-12c to <DENODO_HOME>/lib/data-catalog-extensions.

   You may find the JDBC of other databases in <DENODO_HOME>/lib/extensions/jdbc-drivers/.

3. Log in to Data Catalog with an administrator account and export the metadata. This is necessary because the metadata of Data Catalog is not transferred automatically from the current database to the new one. You can skip this step if this is a fresh installation and you have not done any other change to this Data Catalog.

4. Stop all the components of the Denodo Platform. Then, execute <DENODO_HOME>/bin/webcontainer_shutdown to make sure the web container is stopped.

5. Start Data Catalog and the other components of the Denodo Platform.

6. Log in to Data Catalog with an administrator account and click Administration > Set-Up.

   

   Servers Configuration: configure the internal database¶

   In the section Configure the internal database used by the Data Catalog, provide this information:

   • Select the database you want to use.

   • Driver Class. The default value is usually correct. Name of the Java class of the JDBC driver to be used.

   • URI. Connection URI to the database.

   • Username and Password (optional). Credentials of the account in this external database.

   Data Catalog creates a pool of connections with this database, to speed up the queries. The following settings affect this pool:

   • Max Active Connections (optional). Maximum number of active connections in the pool (zero means no limit).

   • Max Idle Connections (optional). Maximum number of active connections that can remain idle in the (zero means no limit).

   • Max Wait Time (milliseconds) (optional). Maximum amount of time in milliseconds to wait for a connection when all the connections of the pool are in use (-1 means no limit).

   • Ping Query (optional). SQL query used by the pool to verify that a connection obtained from the pool is usable. For Oracle, enter SELECT COUNT(*) FROM SYS.DUAL. This query should be as simple as possible. The documentation of most database vendors recommend a ping query.

   Note

   When the selected database is Derby Embedded, the fields Driver Class, URI, Username and Password are not editable.

7. Click Save. When saving this form, the Data Catalog checks that it can reach this database and that the necessary tables exist. You will be prompted to create the necessary tables if they do not exist yet.

   If you click Yes, the Data Catalog will create the tables for you. If you click No, you have to create them manually. To do this, use the SQL scripts of the directory <DENODO_HOME>/resources/apache-tomcat/webapps/denodo-data-catalog/WEB-INF/classes. You will have to do it with the script if you do not want to grant this user account the privilege to create tables in this database.

   If you are setting-up a cluster of Data Catalog servers, they will store the metadata on the same database. In this scenario, you only have to create the tables in that database once.

8. Restart Data Catalog to apply the changes.

9. Import the metadata you exported on step #3.