Error 1601

Severity

21

Message text

There are not enough 'user connections' available to start a new process. Retry when there are fewer active users, or ask your System Administrator to reconfigure SQL Server with more user connections.

Explanation

Error 1601 occurs when all user connections are in use and a request is made to create another Adaptive Server process.

Error 1601 occurs when all user connections are in use and a request is made to create another Adaptive Server process.Error 1601 is typically caused when Adaptive Server is not configured with enough user connections to support all requests.

Action

Perform the actions from the appropriate sections below.


Too few user connections (all operating systems)

Use sp_configure to increase the value of the number of user connections configuration parameter:

  1. Determine the current number of user connections configured:

    1> sp_configure "number of user connections"
    2> go
    
  2. Set the new value for user connections:

    1> sp_configure "number of user connections",
    2> <new_value> 
    3> go
    
  3. There is no need to restart Adaptive Server in version 15.0 and later.

    If you are running a version of Adaptive Server Enterprise earlier than 15.0, restart Adaptive Server to activate the changes.

Depending on the exact configuration of your Adaptive Server, each user connection typically requires between 40K and 60K of memory, whether or not it is in use. Gradually increase the number of user connections until these errors no longer occur. When you change the value of the number of user connections configuration parameter, you may need to increase the total memory configuration parameter. If you have increased the stack size or default network packet size configuration parameters, each user connection will require more memory. Refer to the Adaptive Server Enterprise performance and tuning guides and the chapter “Configuring Memory” in the System Administration Guide: Volume 2 for information about how Adaptive Server uses memory.

For more information on determining the number of user connections your Adaptive Server needs, refer to “number of user connections” in the chapter Setting Configuration Parameters” in the System Administration Guide: Volume 1.

NoteThis error often appears in the Adaptive Server error log without the 1601 error number: “kernel: no pss structure available for new process.” Take the above action whether or not the error number is displayed.

Additional information

You can obtain more details about user connections by executing the command sp_monitorconfig 'user connections'.

Versions in which this error is raised

All versions