Properties for connecting to high-availability cluster servers through SQLHOST file group entries

You can define sqlhost group entries, so that your application connection attempt is always directed to the primary server of a high-availability cluster, even if failover occurs.

To connect to the primary server of a high-availability cluster, include the following properties in the connection URL or DataSource:

ONEDB_SERVER=group_name
SQLH_TYPE=FILE
SQLH_FILE=sqlhosts
USER=user_name
PASSWORD=password

An exception is thrown if the JDBC driver cannot find a primary server in the group.

Enforcing connections to the primary server is enabled for HCL OneDB™, Version 9.40.xC6 and later only.

Example: Connecting to the primary server of a high-availability cluster through SQLHOST file group entries

In this example, you have the following system setup:

You have a high-availability cluster (my_cluster) that is composed of four servers:
- server_1 (primary), on host1.example.com
- server_2 (shared-disk secondary), on host1.example.com
- server_3 (HDR), on host2.example.com
- server_4 (Remote-standalone secondary), on host3.example.com
The user name on all cluster servers is my_user.
The password on all cluster servers is my_password.

You have a Java™ application server on host4.example.com. The server uses the following sqlhost file entries:

#dbservername   nettype    hostname            servicename   options
 my_servers     -          -                                 c=1,e=server_4
 server_1       onsoctcp   host1.example.com   port_1        g=my_servers
 server_2       onsoctcp   host1.example.com   port_2        g=my_servers
 server_3       onsoctcp   host2.example.com   port_3        g=my_servers
 server_4       onsoctcp   host3.example.com   port_4        g=my_servers

To connect the Java application client to the primary server of my_cluster, use the following URL:

jdbc:onedb://ONEDB_SERVER=my_servers;
   SQLH_TYPE=FILE;SQLH_FILE=sqlhosts;
   USER=my_user_name;PASSWORD=my_password