Qlik Replicate: DB2 z/OS R4Z [SOURCE_CAPTURE ]W: R4DB2: ALL CB ENTRIES ARE IN USE

[Barb_Fill21]

A Qlik Replicate DB2 z/OS task may stop/fail with the following message:

[SOURCE_CAPTURE ]W: R4DB2: ALL CB ENTRIES ARE IN USE 

This means that a task is trying to start, but the maximum number of R4Z Control Blocks (in the  R4Z CDC service environment on the mainframe) is in use. The task will not be able to start unless the MAXSESSIONS setting is increased to allow more than 32 R4Z sessions to start. One temporary solution is to stop some other tasks that are unnecessary to have running at the moment.  Another possible long-term solution is to implement  LOGSTREAM tasks to reduce the number of sessions being created on the mainframe.  Below are the steps to resolve this issue by increasing the total number of sessions. 

Environment

All versions of Qlik Replicate using R4Z
UDTF:     'XXX.your_R4Z_UDTF__CDC1'    <<<   Your  UDTF's CDC server environemnt CDC1, CDC2, DB2T, DB2P as examples.
APPLENV:     'XXX.your_R4Z_APPLENVF__CDC1'    <<<   Your  APPLENV 's CDC server environment CDC1, CDC2, DB2T, DB2P as examples.

Resolution

1. Stop ALL GUI Qlik Replicate DB2 z/OS  ONLY tasks
   
   
2. Wait for the tasks to finish Stopping.
   
3. Run/Submit the XMDUMP Job from the  .INSTALL library. This is a simple reporting job that shows how many sessions are in use and how many are available.
   
   Don't forget to edit the CDCSERV parm = CDC1 or DB2P or whatever your 4 characters are for the CDC service.
   
4. /V WLM,applenv=xxxxxx,Quiesce
   
   This quiesces the application environment associated with the corresponding UDTF and CDC Service, for example, R4Z_MYAPPLENV__CDC1 or R4Z_MYAPPLENV__DB2P)
   
   
5. Run the XMTERMIN Job from the .INSTALL library and expect a return Code: RC=0 The job terminates the CDC service environment ( for example CDC1 or DB2P for Prod) and releases the ECSA memory allocation.
   
   Don't forget to edit the CDCSERV parm = CDC1 or DB2P or whatever your 4 characters are for the CDC service.
   
   
6. Run the XMDUMP Job again, from the .INSTALL library and  expect a return Code: RC=1 = NON-EXISTENT
   
   This verifies that the CDC service environment is truly gone and memory is freed up.
   
7. Edit the .CONFIG file members:
   
   Change all members that contain the MAXSESSIONS setting and increase it by 5 or 10, for example. 
   
   
8. Save the .CONFIG file members
   
   
9.  /V WLM,applenv=xxxx,RESUME
   
   This resumes the application environment associated with the corresponding UDTF and CDC Service, for example, R4Z_MYAPPLENV__CDC1 or R4Z_MYAPPLENV__DB2P.
   
   
10. Resume the Qlik Replicate DB2 z/OS tasks from the Qlik Replicate console.

Related Content 

Controlling the CDC process | Qlik Help