About Hyper PTF: LU18177 (CICS/CTS UNRESPONSIVE)

Products

• Top Secret

Issue/Introduction

Q1.The problem description of LU18177 but was unable to fully understand it.
      Explain the conditions under which CICS/CTS enters into an endless loop (hangs) during a node error (CSNE)?

Q2.How can the LU18177 issue be reproduced?

Q3.How many frequency of occurrence regarding to the problem of LU18177?

Environment

Release : 16.0

Resolution

A1: When a user sign-on multiple times using two or more terminals, and one of the the terminal abruptly results in a node error (CSNE) then at the time of the signing off from the any terminal then CICS/CTS may enter into an endless sign-off loop and become unresponsive.

A2: The problem that reported this issue is using ZNEP to sign-off users. In that process if a node error occurs, and later the user signs-off from the second terminal, the issue gets reproduced.
       In our lab, we modified the code to reproduce this issue. It is nearly impossible without zapping internal control blocks.

A3: This was reported only once in the last five years. Once the CICS/CTS started task is brought up again it works fine.