Using transaction classes to classify workload for WLM
You can use transaction classes to classify client workload for workload management (WLM). The workload that WLM manages consists of different transactions that are targeted to separate servants, each with goals defined by specific service classes. The service classes chosen also determines the WLM goal when Java™ Garbage Collection (GC) is running, which can be CPU intensive. You do not want to set a servant higher in the service class hierarchy than more important work such as production WebSphere®, CICS®, or IMS transaction servers.
Before you begin
You must define the service objectives (goals) for your service classes. You must also define the service objectives of your servers. For more information about defining service objectives (goals) for each service class, see the z/OS MVS™ Planning: Workload Management book, SA22-7602, for example at http://publibz.boulder.ibm.com/epubs/pdf/iea2w131.pdf, or the z/OS WLM web page at http://www.ibm.com/servers/eserver/zseries/zos/wlm/.
About this task
Each transaction is dispatched in its own WLM enclave in a servant process, and is managed according to the goals of its service class. The service class chosen also determines the WLM goal when Java Garbage Collection (GC) is running, which can be CPU intensive.
You should classify the servants to a high STC importance service class so that they are initialized quickly when WLM determines they are needed. However, you do not want to set a servant higher in the service class hierarchy than more important work such as CICS, or IMS transaction servers.
Controllers perform some processing as they receive work into the system, manage the transport handlers, classify a work item, and handle housekeeping tasks. Therefore, controllers should also be classified a high STC importance service class.
You can use the WLM CB-type classification criteria to classify work items:
- Server name (CN)
- Server instance name (SI)
- User ID assigned to the transaction (UI)
- Transaction class (TC)
To classify work using server and userid criteria, use a combination of the WLM Workload Classification rules in the WLM ISPF dialog panels. For more information about defining WLM Classification rules, see Workload management (WLM) and its related article that includes an example of classification rules.
To classify work using transaction classes, you define and use transaction class mappings, as described in this task. The following steps are used to classify work using transaction classes:
Procedure
Example
--------Qualifier-------- -------Class--------
Action Type Name Start Service Report
DEFAULTS: OPS_DEF ________
_____ 1 TN %%DMN ___ OPS_HIGH RWSDMN
_____ 1 TN T5SRV* ___ OPS_MED RT5SRV
_____ 1 TN WS%%%% ___ SYSSTC RWSCTLR
____ 1 TN WS%%%%S ___ OPS_HIGH RWSSRVR
The following table shows classification rules for CB-type work in which the default service class is WSMED and has a reporting class of RWSDEFLT. Work run in the WSPROD server is classified as WSMED with a reporting class of RWSPROD unless it has a transaction class of TCLASS1, TCLASS2, or TCLASS2 assigned through the transaction class mapping file.
Qualifier Qualifier Start Service Report
# type name position Class Class
- --------- -------- -------- -------- --------
Default: WSMED RWSDEFLT
1 CN WSPROD 1 WSMED RWSPROD
2 . TC . TCLASS1 WSFAST RWSPRD1
2 . TC . TCLASS2 WSMED RWSPRD2
2 . TC . TCLASS5 WSSLOW RWSPRD5
1 CN WSTEST 1 WSSLOW RTSTEST
2 . UI . USER1 WSMED RTSTSTU2
2 . TC . TCLASS5 WSSLOW RTSTST5
TransClassMap www.ibm.com:80 /Webap1/myservlet TCLASS1
TransClassMap www.ibm.com:* /Webap1/myservlet TCLASS2
TransClassMap *:443 * TCLASS3
TransClassMap *:* /Webap1/myservlet TCLASS4
TransClassMap www.ibm.com:* /Webap5/* TCLASS5
TransClassMap * * TCLASS6
In this example, all work for BBOC001, except for work running under the user ID DBOOZ, gets classified as CBFAST. Work for DBOOZ gets classified as CBSLOW. All other work, such as work coming from clients outside the cell and including the work for the product runtime servers, gets classified as CBCLASS.
- CBFAST-designed for transactions requiring fast response times.
- CBSLOW-designed for long-running applications that do not require fast response times.
- CBCLASS-designed for remaining work requests.
You design a client workload called BBOC001 that requires fast response times. Also, you want to give work that runs under your manager's user ID (DBOOZ) slower response times. Finally, all remaining work requests should run under the default service class, CBCLASS.
Type column | Name column | Service column | Goal |
---|---|---|---|
CN | BBOC001 | CBFAST | 90% complete in 2 seconds |
UI | DBOOZ | CBSLOW | Velocity 50, importance = 3 |
(default) | (blank) | CBCLASS | Discretionary |
- Issue IWMARIN0 and choose option
4:
File Utilities Notes Options Help -------------------------------------------------------------------------- Functionality LEVEL003 Definition Menu WLM Appl LEVEL004 Command ===> ______________________________________________________________ Definition data set . . : 'CB.MYCB.WLM' Definition name . . . . . CB390 (Required) Description . . . . . . . WLM Setup for the product Select one of the following options. . . . . 4__ 1. Policies 2. Workloads 3. Resource Groups 4. Service Classes 5. Classification Groups 6. Classification Rules 7. Report Classes 8. Service Coefficients/Options 9. Application Environments 10. Scheduling Environments
- Create a service class called CBFAST and specify that it be 90% complete in 2 seconds.Note: The example assumes you have defined a workload called ONLINE.
Service-Class Notes Options Help -------------------------------------------------------------------------- Create a Service Class Row 1 to 2 of 2 Command ===> ____________________________________________________ Service Class Name . . . . . . CBFAST (Required) Description . . . . . . . . . Quick CB transactions Workload Name . . . . . . . . ONLINE (name or ?) Base Resource Group . . . . . ________ (name or ?) Specify BASE GOAL information. Action Codes: I=Insert new period, E=Edit period, D=Delete period. ---Period--- ---------------------Goal--------------------- Action # Duration Imp. Description __ __ 1 1 90% complete within 00:00:02.000 ******************************* Bottom of data ******************************** .-----------------------------------------------------------------------. | Press EXIT to save your changes or CANCEL to discard them. (IWMAM970) | '-----------------------------------------------------------------------'
- Save the service class. You see the
following:
Service-Class View Notes Options Help -------------------------------------------------------------------------- Service Class Selection List Row 1 to 14 of 21 Command ===> ______________________________________________________ Action Codes: 1=Create, 2=Copy, 3=Modify, 4=Browse, 5=Print, 6=Delete, /=Menu Bar Action Class Description Workload __ CBFAST Quick CB Transactions ONLINE ******************************* Bottom of data ********************************
- Repeat these steps for the CBSLOW service class.
- Create classification rules using the new service class. Choose option 6 on the main
panel:
File Utilities Notes Options Help -------------------------------------------------------------------------- Functionality LEVEL003 Definition Menu WLM Appl LEVEL004 Command ===> ______________________________________________________________ Definition data set . . : 'CB.MYCB.WLM' Definition name . . . . . CB390 (Required) Description . . . . . . . WLM Setup for the product Select one of the following options. . . . . 6__ 1. Policies 2. Workloads 3. Resource Groups 4. Service Classes 5. Classification Groups 6. Classification Rules 7. Report Classes 8. Service Coefficients/Options 9. Application Environments 10. Scheduling Environments
- Create a set of rules for your service
classes:
Subsystem-Type Xref Notes Options Help -------------------------------------------------------------------------- Create Rules for the Subsystem Type Row 1 to 2 of 2 Command ===> ____________________________________________ SCROLL ===> PAGE Subsystem Type . . . . . . . . CB (Required) Description . . . . . . . . . WebSphere classification Fold qualifier names? . . . . Y (Y or N) Action codes: A=After C=Copy M=Move I=Insert rule B=Before D=Delete row R=Repeat IS=Insert Sub-rule -------Qualifier------------- -------Class-------- Action Type Name Start Service Report DEFAULTS: CBCLAS ________ ____ 1 CN BBOC001 ___ CBFAST ________ ____ 1 UI DBOOZ ___ CBSLOW ________ ****************************** BOTTOM OF DATA ******************************