What you have to do to use CICSPlex® SM’s workload management functions
varies depending on whether you want to implement workload balancing only, or whether
you also want to implement some workload separation, and possibly define one or more
transaction affinities in the same CICSplex. You are recommended to follow this
process:
- Identify candidates for dynamic routing
- Implement workload balancing for each workload in the CICSplex where dynamic routing
is possible.
- Add any necessary workload separation requirements.
- Define any intertransaction affinities.
Each step is described in the remainder of this section.
Not all work requests are candidates for dynamic routing. The conditions
that have to apply for a work request to be eligible are listed in the CICS® Intercommunication Guide.
For further details:
- See the CICS Application Programming Guide and the CICS Application Programming Reference for descriptions of the EXEC CICS LINK and EXEC CICS START commands.
- See CICS Business Transaction Services for a description of the EXEC
CICS RUN ASYNCHRONOUS command.
- See either the CICS Resource Definition Guide or CICSPlex System Manager Managing Business Applications for resource definitions.
- See the Information Center section Java™ Applications in CICS for
all information on enterprise beans.
- See the CICS External Interfaces Guide for more information about
the Link3270 bridge.
To implement workload balancing within a CICSplex, your task is very straightforward:
- If there is more than one routing region in a single workload, create a CICS
system group of those routing regions, using the CICSGRP object.
- Create a CICS system group of the target regions to which the routing regions can
route transactions, using the CICSGRP object. This group could include every
CICS system in the CICSplex.
- Create one workload specification for each workload in the CICSplex, using the WLMSPEC
object. In the workload specification, specify the name of the target system group as the
target scope value, and identify which algorithm is to be used for workload balancing.
- Associate the single routing region, or the routing system group, with the workload specification.
(Remember that you can have multiple workloads in single CICSplex, but that a routing region
or group of routing regions can belong to only one active workload specification at a time.)
Workload balancing is effective within the workload when a routing region belonging to the
workload is next started.
To implement workload separation in the same workload, by
any combination either of user id, terminal id, and transaction group, or
of process type and transaction group:
- Create a CICS system group for each set
of target regions, using the CICSGRP object. For example, if:
- Transactions initiated by users ABC* from terminals NETA* must be routed
to target regions 2 through 7
and
- Transactions initiated by users HIJ* from any terminal must be routed
to target regions 5 through 9
two target system groups must be defined: one group includes target regions
2 through 7, and one group includes target regions 5 through 9.
- Define a transaction group, using the TRANGRP object, if workload separation by
transaction is to be implemented. For example, if transactions EFG1, EFG2,
and EFG3 must be routed to a specific group of target regions, you must define
a transaction group to include those transactions.
- Create one workload definition, using the WLMDEF object, for each user, terminal,
and transaction group combination. For the example in item 1 (above):
- One workload definition would be required for the combination of any transaction,
users ABC*, and terminals NETA*.
- One workload definition would be required for the combination of any transaction,
users HIJ*, and any terminal.
A third workload definition would be required to support the workload separation by transaction
described in item 2. In each workload definition, include the name
of the appropriate target region system group to which eligible transactions are
to be routed.
- If the workload definitions are to be installed automatically when the first requesting region
in the workload starts, you should use the WLMGROUP object to:
- Create a workload group.
- Add the workload definitions to the workload group.
- Associate the workload group with the workload specification.
Automatic installation of the workload definitions is
likely to be required, because workload separation is usually a regular and consistent
requirement. However, you can also install a workload group or individual workload definitions
manually for immediate effect.
If there is a requirement for multiple transactions in the workload to
be processed by the same target region:
- Create a transaction group, using the TRANGRP object, for each set
of transactions within the workload that share an affinity. For example, if
transactions MNO1, MNO2, and MNO3 must be processed by the same target region (perhaps
because they run in sequence and leave data for the next transaction), define
a transaction group to include those three transactions specifying the affinity type
and its duration.
- If you want to implement workload separation, create a workload definition for each transaction group
and user or terminal pattern, using the WLMDEF object. For example, if the
intertransaction affinity described in item 1 (above)
applies to any user from terminals NYORK*, the workload definition must include that
information. In addition, the workload definition identifies the set of target regions from
which CICSPlex SM can select one. This could be every target region in the CICSplex, or
some subset of target regions.
Note that you can define an intertransaction
affinity to CICSPlex SM without also implementing workload separation. In this case, no workload definition
is required and CICSPlex SM routes the first transaction in the group to a suitable target region
from the set identified in the workload specification. Subsequent transactions in the transaction group
are routed to the same target region while the affinity is active.
- If the workload definitions are to be installed automatically when the first routing region
in the workload starts, you should use the WLMGROUP object to:
- Create a workload group.
- Add the workload definitions to the workload group.
- Associate the workload group with the workload specification.
You can also install a workload group or individual workload definitions manually for
immediate effect.
Note:
It’s important that you define routing regions and target regions
in groups, to ensure that changes to the composition of those groups are automatically
reflected in CICSPlex SM’s workload management.
When you decide to implement WLM functions in your enterprise, you should
begin by defining the appropriate objects. You should:
- Use the WLMDEF view to create a workload definition.
- Use the WLMGROUP view to create a workload group.
- Use the WLMSPEC view to create a workload specification.
Then, to create associations between these objects:
- Use the WLMDEF view to add the workload definition to the workload group.
- Use the WLMGROUP view to add the workload group to the workload specification.
- Use the WLMSPEC view to associate the workload specification with a CICS system
or CICS system group.
You can use the MAP action command to display a visual map of the WLM
definitions in your data repository. If you want to see a list of the objects and associations
you have already defined, use the WLMINGRP, WLMINSPC, and WLMSCOPE views.
CICSPlex SM includes a Starter Set of CICSPlex SM object definitions
that illustrates the concepts and components introduced in this chapter. The Starter Set
is described in detail in The CICSPlex SM Starter Set.
If you have problems defining any particular object or association, refer
to the CICSPlex SM Starter Set examples. The Starter Set includes many WLM examples that
you can use as models for your own objects. You can copy the supplied samples
directly into your data repository via the batched repository-update facility. For more information about using
the Starter Set as a model see the CICS Transaction Server for z/OS® Installation Guide. For
information about the batched repository-update facility, see CICSPlex System Manager Administration.
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