User added to shared UAMS from one system not showing in others.

Products

• CMDB for z/OS
• NetSpy Network Performance
• NetMaster Network Automation
• SOLVE
• NetMaster Network Management for SNA
• NetMaster Network Management for TCP/IP
• NetMaster File Transfer Management

Issue/Introduction

Problem: 

Have NetMaster running on 3 systems sharing a UAMS dataset. After adding a user (using /UAMS from within NM), it does not show up on other systems.

Environment

You are sharing a UAMS file across multiple regions defined with share options 3 3. 

 

Cause

 

VSAM share options 3 3 utilizes buffered IO to and from the physical VSAM file that may not occur until either the VSAM buffer becomes full or the file is closed when a region is shut down or restarted. This in turn may cause updates to the UAMS file from the updating region to not be immediately visible to other regions sharing the file until either of those conditions are met. 

 

Resolution

Unfortunately, there is not a way to force physical IO to or from the VSAM file when share options 3 3 are used, so in order to see an immediate update it may be necessary to recycle the regions involved for the physical IO to occur. 

 

 

Additional Information:  

 

Data integrity is another concern when using share options 3 3. If simultaneous updates are performed from multiple regions, then the potential for data corruption exists. Because of this, we recommend using VSAM RLS (Record Level Sharing) when sharing the UAMS file. This method guarantees data integrity and also makes updates to the UAMS file immediately visible to all sharing regions. To enable RLS support for your UAMS file follow these steps:

 

1. Verify that VSAM RLS processing is available in your parallel sysplex.
2. Allocate the data set to be SMS managed, and specify the LOG(NONE) parameter in the DEFINE CLUSTER or ALTER CLUSTER command for the data set.
3. Specify a cache set on the storage class with at least one of the associated CF cache structures available.
4. Set the RLS VSAM Option for your UAMS data set by specifying the XOPT=RLSU parameter in your region RUNSYSIN member.