Enabling request-level Reliability Availability and Serviceability (RAS) granularity

You can enable request-level Reliability Availability and Serviceability (RAS) granularity for HTTP, IIOP, optimized local adapter, and certain MDB requests by defining RAS attributes in the workload classification document. With request-level RAS granularity, you can specify RAS attribute values for specific requests, such as a unique dispatch timeout value for all HTTP requests with a URI that ends in .jpg.

1. Develop the workload classification document.
   Use the information in the workload classification file topic to create the document. The topic contains examples of the workload classification document, with and without RAS attributes. Use one workload classification document whether you are using it to classify z/OS® workload or to implement request-level RAS granularity.
2. If you create the document on a z/OS system in code page IBM-1047, the normal code page for files that exist in the HFS, convert the file to ASCII before you use the file.
   Use one of the following options to convert a working document into a document that can be used by the server:

   • native2ascii
     This is a utility in the Java™ SDK that can convert a file from the native code page to the ASCII code page. For example, if you are working on an XML document called x5sr02.classification.ebcdic.xml and you want to create a document called x5sr02.classification.xml, use the following command:

     /u/userid $ native2ascii \
     x5sr02.classification.ebcdic.xml > x5sr02.classification.xml

     The command line is split with the backslash (\) character to the next line for publication purposes.
   • iconv
     This is a z/OS utility that can convert files from one designated code page to a different designated code page. For example, if you are working on an XML document called x5sr02.classification.ebcdic.xml and you want to create a document called x5sr02.classification.xml, use the following command. The $ character is the prompt.

     /u/userid $ iconv -f IBM-1047 -t UTF-8 \
     x5sr02.classification.ebcdic.xml >x5sr02.classification.xml

     The command line is split with the backslash (\) character to the next line for publication purposes.
   • Create the document on your workstation and then FTP the file to the correct location on the z/OS system in binary format. By using this option, you can also create the Classification.dtd file in the same directory as the workload classification document. Then, you can perform an XML validity check on the document before installing it on a server. Use any type of validating parser. For example, you can use WebSphere® Application Developer workbench to construct and validate the workload classification document.
3. Specify the location of the workload classification document in the administrative console.
   Use the wlm_classification_file variable to specify the XML file that contains the classification information. In the administrative console, click Environment > WebSphere variables > New. You can set the variable at the cell, node, or server instance level. If you specify the variable at the cell or node level, the information must be accessible and applicable to all the servers that inherit the specification from the node or cell.
4. Implement the changes to the file.
   You can restart the application server or reload the workload classification document without having to restart the application server:

   • Restart the application server.
   • Reload the workload classification document by issuing the following command:

     MODIFY|F <servername>,RECLASSIFY,FILE='/path/to/newfile.xml'

   If the workload classification document is not a well formed, valid XML document, it is ignored by the application server and the following message is displayed:

   BBOJ0085E PROBLEMS ENCOUNTERED PARSING WLM CLASSIFICATION XML FILE (0)

5. Use the DISPLAY WORK operator command to display classification information. Use this command to determine if your classification scheme is classifying the work as you intended.
   Issue the following command to display the IIOP, HTTP, INTERNAL, SIP, MDB, and optimized local adapter classification information:

   MODIFY|F <servername>,DISPLAY,WORK,CLINFO

   Issue this command against each application server.

   The following example shows a possible result of issuing the new operator command:

   00- SY1  f bbos001,display,work,clinfo                                      
         SY1  BBOJ0129I: The /tmp/wlm4.class.xml workload classification file was loaded at   
         2009/07/14 19:33:35.297 (GMT).                                           
         SY1  BBOO0281I CLASSIFICATION COUNTERS FOR IIOP WORK                    
         SY1  BBOO0282I CHECKED 0, MATCHED 0, USED 0, COST 2, DESC: IIOP root    
         SY1  BBOO0282I CHECKED 0, MATCHED 0, USED 0, COST 4, DESC: leotag       
         SY1  BBOO0282I CHECKED 0, MATCHED 0, USED 0, COST 3, DESC: byetag       
         SY1  BBOO0282I CHECKED 0, MATCHED 0, USED 0, COST 4, DESC: hellotag     
         SY1  BBOO0283I FOR IIOP WORK: TOTAL CLASSIFIED 0, WEIGHTED TOTAL COST 0 
         SY1  BBOO0281I CLASSIFICATION COUNTERS FOR HTTP WORK                    
         SY1  BBOO0282I CHECKED 2, MATCHED 2, USED 0, COST 2, DESC: HTTP root    
         SY1  BBOO0282I CHECKED 2, MATCHED 2, USED 0, COST 4, DESC: plantta4     
         SY1  BBOO0282I CHECKED 2, MATCHED 1, USED 1, COST 3, DESC: giftag4      
         SY1  BBOO0282I CHECKED 1, MATCHED 1, USED 1, COST 4, DESC: jpgtag4      
         SY1  BBOO0283I FOR HTTP WORK: TOTAL CLASSIFIED 2, WEIGHTED TOTAL COST 7 
         SY1  BBOO0188I END OF OUTPUT FOR COMMAND DISPLAY,WORK,CLINFO            

   An explanation of the command output:

   BBOJ0129I:The file workload classification file was loaded attime.

   The message indicates the workload classification file currently active and the time that it was loaded.

   BBOO0281I CLASSIFICATION COUNTERS FOR type WORK

   The header message for messages that display the usage of the workload classification rules. The value of type can be HTTP, IIOP, INTERNAL, SIP, OLA, or MDB.

   Important: The display command does not include output for the classification type of SIBUS.

   BBOO0282I CHECKED n1, MATCHED n2, USED n3, COST n4, DESC: text

   This message displays information about a particular rule in the workload classification. This message displays the following information:

   • n1 - The number of times the rule has been examined.
   • n2 - The number of times that this rule has been matched by the request.
   • n3 - The number of times that this rule has been used.
   • n4 - The cost of using the rule, or the number of compares that are required to determine if this rule is the correct rule to use.
   • text - The descriptive text from the classification rule so that you can tell which classification rule is being displayed.

   BBOO0283I FOR type WORK: TOTAL CLASSIFIED n1, WEIGHTED TOTAL COST n2

   This message shows the summary information for the IIOP, HTTP, INTERNAL, SIP, MDB, or optimized local adapter work classification. This message displays the following information:

   • type - The type of work that is being displayed. The value must be IIOP, HTTP, INTERNAL, SIP, MDB, or OLA.
   • n1 - The number of requests that were classified using the classification rules.
   • n2 - The weighted total cost, calculated by taking the number of times that each rule was used multiplied by the cost, or number of rule compares that were done, of using the rule and adding those up across all the rules.

   The total cost n2 divided by the total number of requests classified n1 equals the cost of using the table. The closer that the value is to one, the lower the cost of using the defined rules. A value of 1 indicates that there is just the default classification, so no requests match it.

6. Repeat these steps until you achieve the RAS granularity that you want.