The Web User Interface (WUI) in Figure 4 shows algorithm types specified at the WLM specification level.
Figure 4 shows that WLM specification GWS has an algorithm type of GOAL. If WLM specification GWS is selected and mapped, the WLM groups, WLM definitions, and transaction groups associated with GWS can be seen (see Figure 5).
If transaction group TRANGRP is selected in the transaction group definitions column in Figure 5, the algorithm type specified at the transaction group level is actually QUEUE (see Figure 6). This means that WLM algorithm type QUEUE will override the algorithm type GOAL, specified at the WLMSPEC level, for those transactions associated with transaction group TRANGRP.
The Order of Precedence of Link Types
CICSPlex SM WLM optimizes processor capacity by making decisions to dynamically route transactions and programs to the most appropriate target region.
When executing its dynamic routing algorithm, CICSPlex SM WLM assigns a predefined arithmetic value based on the type of link between a routing region and candidate target region. This value is used as a multiplier against the target region's task load as part of the routing weight calculation of a target region. The region with the lightest weight is normally selected as the target region.
Prior to CICS TS 4.2, IP Interconnectivity (IPIC) was slower than Logical Unit 6.2/Advanced Program-to-Program Communication (LU6.2/APPC). So IPIC was allocated a higher arithmetic value to make it less preferable compared to other link types. Because IPIC is now faster than LU6.2/APPC, it’s now allocated a lower arithmetic value than LU6.2/APPC to make it more preferable. So, on occasions of significant workload, more dynamic route requests would be routed to the target regions over IPIC than over LU6.2/APPC.
The link-type order of precedence a router now employs is:
- Local (faster than MRO/XM)
- MRO/XM (faster than MRO/XCF)
- MRO/XCF (faster than IPIC)
- IPIC (faster than LU6.2/APPC)
- APPC (faster than an indirect connection)
- Indirect connection.
This behavior is recognized only for queue mode and goal mode dynamic routing. The link neutral algorithms specifically omit the link type factor from the algorithm execution, causing all targets to be regarded as having the same link speed.
Unit of Work (UOW) Affinities With Distributed Program Link