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Can a DBSERVERNAME and listener thread be added dynamically without bouncing the database server?

Technote (FAQ)


Can we add a DBSERVER entry dynamically to the SQLHOSTS file without bouncing the database server?


A need exist to add a new connection to the instance dynamically without any down time.


Starting with Informix version 11.50.xC6 we have the ability to Dynamically Start, Stop and Restart Listen threads with the onmode -P command or by using the SQL Admin API.

This feature allows a new listener thread to be started on a port without the need to restart the database server. Adding new entries in to the sqlhosts file and the DBSERVERALIAS parameter of the onconfig file and executing the onmode -P or SQL API commands will allow new connections to utilize the new server name.


1. Modify the sqlhosts to add the new connection:

      new_test_tcp onsoctcp myhost 4567

2. Modify the DBSERVERALIAS parameter of the onconfig file:

      DBSERVERALIASES main_prim_shm:new_test_tcp

3. Start a listener thread for the new alias:

       onmode -P start new_test_tcp

OR use the sysadmin SQL API :

      execute function admin("start listen","new_test_tcp");

Document information

More support for: Informix Servers

Software version: 11.5, 11.70, 12.1

Operating system(s): AIX, HP-UX, Linux, Solaris

Reference #: 1634793

Modified date: 18 April 2013