(ZOS) Use transaction classes to classify workload for WLM
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. We 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.
Transaction class mapping file support is deprecated. We should use a workload classification document instead of a transaction class mapping file to classify work requests in a z/OS environment.
We must define the service objectives (goals) for our service classes. We must also define the service objectives of the 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/.
We do not have to define special classification rules and work qualifiers initially. However, they should be defined before this system becomes a production system.
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.
We should classify the servants to a high STC importance service class so that they are initialized quickly when WLM determines they are needed. However, we 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.
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, we define and use transaction class mappings, as described in this task. The following steps are used to classify work using transaction classes:
Tasks
- Define transaction class mappings based on the HTTP virtual host name, port number, and URI (Universal Resource Identifier - encoded address for any resource on the Web) provided with each work HTTP or HTTPS request.
- Create a Transaction Class mapping file (as a simple text file). For example: /wasconfig/t5was/MyTrMapFile.txt
Important: This file must be in EBCDIC format.
- Edit the Transaction Class mapping file to define each transaction class mapping to use. Define each mapping on a separate line, using the following syntax:
TransClassMap host:port uritemplate tclassUse wildcard characters for the host and port fields fi we use them for both fields. For example:
TransClassMap wsc4.washington.ibm.com:9080 /MyIVT/index.* TCLMYIVT TransClassMap wsc4.washington.ibm.com:9080 /MyIVT/ivtejb TCLMYEJB TransClassMap wsc4.washington.ibm.com:* /SuperSnoop* TCLSNOOP TransClassMap wsc4.washington.ibm.com:* /ssb/* TCLSSB TransClassMap *:* /admin* TCLADMIN
- Specify the Transaction Class mapping file on the administrative properties for each server that is to handle work classified by transaction class. To specify the Transaction Class mapping file for a server:
- In the administrative console, click...
Servers > Server Types > WebSphere application servers > server. Then, in the Container Settings section, click Container settings > Web container.
- In the Additional Properties section, click z/OS additional settings.
- In the Transaction Class Mapping field, the fully qualified name of the Transaction Class mapping file that you edited in a previous step. For example: /wasconfig/t5was/MyTrMapFile.txt
- To use a transaction class to classify outbound data that is delivered in response to HTTP and HTTPS requests, select the TCLASS option in the Network QoS field. If we specify TCLASS, the product uses the transaction class value used to classify the inbound request to the z/OS Workload Manager.
Example
The following table shows classification rules for STC-type work that covers the controller and servant regions started tasks:
--------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 RWSSRVRThe 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 RTSTST5The following table shows how work can be assigned a transaction class based on its host name, port number, or URI. For example, a web request of http://ibm.com:80/Webap1/myservlet handled by the WSPROD server would be assigned a transaction class of TCLASS1, a service class of WSFAST, and a reporting class of RWSPRD1 as per the classification rules..
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 * * TCLASS6Example of the application of classification rules.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.
For the purpose of this example, let us assume we have three workload management service classes defined for the product(subsystem type CB):
- 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, we 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.
You could set the following performance goals through IWMARIN0:
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.
The example assumes we 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 the 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 our 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 ******************************
Subtopics
- Transaction class mapping file entries
Transaction class mapping file entries indicate the workload management (WLM) goal for each class of client work. Each client transaction is dispatched in its own WLM enclave in a servant region process, and is managed according to the goals specified for its service class.- Controller and Servant WLM classifications
Applications are deployed on a server or a cluster of servers. Each server consists of a controller and one or more servants. Each controller is started by the deployment manager, or by an MVS operator command as an MVS started tasks. Each servant is started by the Workload manager (WLM) as it is needed.