LIMITNUMSESSIONS configuration parameter

Use the LIMITNUMSESSIONS configuration parameter to define the maximum number of sessions that you want connected to HCL Informix®.

If you specify a maximum number, you can also specify whether you want Informix to print messages to the online.log file when the number of sessions approaches the maximum number.

If the LIMITNUMSESSIONS configuration parameter is enabled and sessions are restricted because of this limit, both regular user threads and DBSA user threads connecting to any database count against the limit. However, a DBSA user is allowed to connect to the server even after the limit has been reached.

Distributed queries against a server are also counted against the limit.

The LIMITNUMSESSIONS configuration parameter is not intended to be used as a means to adhere to license agreements.

onconfig.std value
Not set in the onconfig.std file
maximum_number_of_sessions = 0 to 2,097,152 (2*1024*1024). The default is 0.
print_warning = 0 (off) or 1 (on). The default for this optional value is 0.
takes effect
After you edit your onconfig file and restart the database server.
When you reset the value dynamically in your onconfig file by running the onmode -wf command.
When you reset the value in memory by running the onmode -wm command.


If the print_warning is set to 1, a warning is triggered when the number of sessions is greater than or equal to 95 percent of the maximum_number_of_sessions value. If print_warning is set to zero, or if it is not set, no warning is issued No new user sessions can be opened after the maximum_number_of_sessions limit is reached.

If the maximum_number_of_sessions value for the LIMITNUMSESSIONS configuration parameter is set to 0, or if it is not set, there is no limit to the number of sessions that can connect to the server.

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

The settings in this example cause a warning to be printed when more than 94 sessions are concurrently connected. Only a member of the DBSA group can start a new session when 100 sessions are already connected.

Use onmode -wf or onmode -wm, or the equivalent SQL administration API ONMODE commands, to dynamically increase or temporarily disable the LIMITNUMSESSIONS setting. Use this configuration parameter to allow administrative utilities to run if the database server is reaching the maximum_number_of_sessions limit.

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