Properties for connecting to high-availability cluster servers through HCL Informix® Connection Managers

A JDBC application can connect to Connection Manager, just as the application might connect to a database server. Application connection requests are then redirected to the most appropriate server in a high-availability cluster.

You can configure multiple Connection Managers, and then create a Connection Manager group entry in sqlhost file that is used by the Java™ application server. If one Connection Manager fails, connection requests can be directed to working Connection Managers. The SQLH_FILE connection property directs the JDBC driver to search for group entries.

To connect to the HCL Informix® Connection Manager that then connects to the servers of a high-availability cluster, you must include the following properties in the connection URL or DataSource:

INFORMIXSERVER=CM_or_group_name
SQLH_TYPE=FILE
SQLH_FILE=sqlhosts
USER=user_name
PASSWORD=password

Include the following properties in the connection URL to prevent your Java™ applications from waiting indefinitely if a Connection Manager is running, but has a hung connection.

INFORMIXCONRETRY=value
INFORMIXCONTIME=value
LOGINTIMEOUT=value

The values are set based on the network environment.

Example 1: Connecting to a high-availability cluster through the HCL Informix® Connection Manager

In this example, you have the following system setup:

You have a high-availability cluster (my_cluster) that is composed of four servers.
The user name on all cluster servers is my_user.
The password on all cluster servers is my_password.

connection_manager, on cmhost1.example.com uses the following configuration file:

NAME connection_manager

CLUSTER my_cluster
{
   INFORMIXSERVER my_servers
   SLA sla_primary     DBSERVERS=PRI
   SLA sla_secondaries DBSERVERS=SDS,HDR,RSS
   FOC ORDER=ENABLED \
       PRIORITY=1
}

You have a Java™ application server on host1.example.com, and the Java™ application server uses the following sqlhost file entries:

#dbservername       nettype    hostname             servicename  options
 sla_primary      onsoctcp   cmhost1.example.com  cm_port_1
 sla_secondaries  onsoctcp   cmhost1.example.com  cm_port_1

If the initial connection attempt by the client fails, you want it to retry two times.
You want the CONNECT statement to wait 10 seconds to establish a connection.
You want the connection to fail if the server port is polled and does not connect within 10 milliseconds.

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

jdbc:informix-sqli://INFORMIXSERVER=sla_primary;
   SQLH_TYPE=FILE;SQLH_FILE=sqlhosts;
   USER=my_user_name;PASSWORD=my_password;
   INFORMIXCONRETRY=2;INFORMIXCONTIME=10;LOGINTIMEOUT=10

To connect the Java™ application client to a secondary server of my_cluster, use the following URL:

jdbc:informix-sqli://INFORMIXSERVER=sla_secondaries;
   SQLH_TYPE=FILE;SQLH_FILE=sqlhosts;
   USER=my_user_name;PASSWORD=my_password;
   INFORMIXCONRETRY=2;INFORMIXCONTIME=10;LOGINTIMEOUT=10

Example 2: Connecting to a high-availability cluster through HCL Informix® Connection Managers

In this example, you have the following system setup:

You have a high-availability cluster (my_cluster) that is composed of four servers.
The user name on all cluster servers is my_user.
The password on all cluster servers is my_password.

connection_manager_1, on cmhost1.example.com uses the following configuration file for client redirection and failover:

NAME connection_manager_1

CLUSTER my_cluster
{
   INFORMIXSERVER my_servers
   SLA sla_primary_1 DBSERVERS=PRI
   FOC ORDER=ENABLED \
       PRIORITY=1
   CMALARMPROGRAM $INFORMIXDIR/etc/CMALARMPROGRAM.sh
}

connection_manager_2, on cmhost2.example.com uses the following configuration file for client redirection and failover:

NAME connection_manager_2

CLUSTER my_cluster
{
   INFORMIXSERVER my_servers
   SLA sla_primary_1 DBSERVERS=PRI
   FOC ORDER=ENABLED \
       PRIORITY=2
   CMALARMPROGRAM $INFORMIXDIR/etc/CMALARMPROGRAM.sh
}

You have a Java™ application server on host1.example.com, and the Java™ application server uses the following sqlhost file entries:

#dbservername       nettype    hostname             servicename  options
 g_primary          group      -                    -            c=1,e=sla_primary_2
 sla_primary_1      onsoctcp   cmhost1.example.com  cm_port_1    g=g_primary
 sla_primary_2      onsoctcp   cmhost2.example.com  cm_port_2    g=g_primary

If the initial connection attempt by the client fails, you want it to retry two times.
You want the CONNECT statement to wait 10 seconds to establish a connection.
You want the connection to fail if the server port is polled and does not connect within 10 milliseconds.

To connect the Java™ application client to the primary server of my_cluster through either connection_manager_1 or connection_manager_2, use the following URL:

jdbc:informix-sqli://INFORMIXSERVER=g_primary;
   SQLH_TYPE=FILE;SQLH_FILE=sqlhosts;
   USER=my_user_name;PASSWORD=my_password;
   INFORMIXCONRETRY=2;INFORMIXCONTIME=10;LOGINTIMEOUT=10