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We see WLM enclaves tied to NetMaster SSI. What is their purpose?

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Article ID: 229847

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Updated On:

Products

NetMaster Network Management for TCP/IP NetMaster File Transfer Management NetMaster Network Automation SOLVE:Operations Automation

Issue/Introduction

We are are seeing WLM enclaves tied to NMSTRSSI. What does NetMaster use them for? 

We are concerned about potential impacts to batch performance as they run in the SYSSTC service class.

Environment

Release : 12.2

Component : NetMaster Network Management for TCP/IP

Resolution

These WLM enclaves are to facilitate zIIP processing. A ‘ziip-eligible’ SRB must be an enclave SRB.  

The Packet Analyzer  and Netmaster use ‘enclave SRBs’ which were created in the mid-90’s as part of MVS/ESA 5.2.  These SRBs are like lightweight tasks, and have a priority scheme exactly the same as a task (TCB).  They are preemptable, and cannot kill the system if they loop.

For Netmaster, we create an enclave (we need to do this so that we can ziip-enable it), and that enclave inherits the address space dispatching priority (as set by WLM etc).  Thus, the enclave SRB gets exactly the same dispatching priority as the address space and/or existing task(s) (TCBs).

So in short,  The zIIP processor allows certain existing z/OS workloads to execute on the zIIP processor. For these workloads to execute on the zIIP processor, they must execute as a Work Load Managed (WLM) Enclave SRB.