Informix Experts

History:

Through online forums and technical support cases, Informix users have requested the ability to limit the number of connections to IDS servers.

Introduction:

Available now in 11.50 IDS, the ONCONFIG parameter, LIMITNUMSESSIONS, can be used to define the maximum number of sessions that you want connected to IDS.

This ONCONFIG parameter uses the following syntax:

LIMITNUMSESSIONS maximum_number_of_sessions, print_warning

The maximum_number_of_sessions option defines the limit for the maximum number of sessions and can be set to a value in the range of 0 to 2,097,152. The value of 0 is the default and indicates that this feature is turned off.

The print_warnings option can be set to 1 or 0. When this value is set to 1, a warning message is written to the online.log when the number of sessions approaches the limit. These warning messages are not reported when the value is set to 0. The default is 0.

The limit imposed by LIMITNUMSESSIONS takes effect when the database server is shut down and restarted. It can also be started, modified or stopped dynamically by using onmode –wf or onmode –wm.

When the number of connections reaches this limit, new connection requests are rejected with the error -25571 Cannot create a user thread, until the number of connections fall below this limit. A message is reported to the online.log when this limit has been reached.

Database Server Administrators (DBSAs) are the exception to this limit. When the limit has been reached, a DBSA user will still be allowed to connect to IDS.

Example:

The following example specifies that you want a maximum of 100 sessions to connect to the server and that you would like a warning message printed to the online.log when the number of connected sessions approaches 100.

LIMITNUMSESSIONS 100,1

For more information:

Disclaimer:

This feature is not intended to enforce terms or conditions of the User License Agreement.