What causes return code 24 (013) EXCLUSIVE CONTROL EVENTS EXCEEDED and how can it be avoided?

Products

• Datacom
• DATACOM - AD
• Datacom/DB
• Datacom/AD

Issue/Introduction

I am getting return code 24 (013)  EXCLUSIVE CONTROL EVENTS EXCEEDED

What causes this error and how can it be avoided?

What is the recommended value for EXCTLNO in the MUF startup?

 

 

 

Environment

Release: 15.1
Component: Datacom/DB

Cause

The return code 24 means the number of EXCLUSIVE CONTROL events for a task have been exceeded.

This value is specified in the MUF startup parameter EXCTLNO and is maximum number of records that one task can have under primary exclusive control. 

Resolution

There is no recommended value for EXCTLNO, it depends on the way your applications are coded and how many records need to be held under exclusive control at any one time.  
Datacom is distributed with EXCTLNO defined with a value of 0, this means there is no limit. Specifying 0 or too high a value could result in other tasks having to wait for exclusive control.

To prevent the error either change the logic of the program to issue regular COMMITs or  increase the value for EXCTLNO.  

EXCTLNO can also be issued as a console command. The format of the command in DBUTLTY is:

COMM OPTION=CONSOLE,OPTION2='EXCTLNO nnnn'

Or from the console issue: 

F mufjob,EXCTLNO nnnn

 

Additional Information

See the Datacom documentation section EXCTLNO