Specifying trace options

To specify trace options

1. Define a trace by using mostly defaults.

   Keyword	Operand/Description
   PARM	id If you want to run multiple trace requests, specify an ID in the PARM field to make the trace unique. The identifier is used to specify which set of trace data is to be displayed with the application trace services. Note Blanks can be used as an identifier for one trace, but BMC does not recommend this usage.
   TYPE	S | D S (the default) requests a summary application trace of completed transactions. D requests a detail application trace that also collects major events in the life of the transaction.
   STORAGE	n Note In windows mode, display storage is managed by BMC AMI Ops Infrastructure; the STORAGE keyword is not used. For full-screen trace displays, this value determines the size of the online trace display buffer to contain the trace entries per active trace. The size is specified in K format, where K is the number of 1024 byte blocks; for example, 200K is 200*1024=204800 bytes This value is primed from the default specified in DMRBEXxx. If no value is specified, the value from BBIISPxx is used. For a detail trace, this value must be at least four times TRSIZE. If the specification is less than four times TRSIZE, it will be adjusted upward to the maximum of 16383K.
   LOGTRAC	N | Y This value specifies whether to write all trace records for this request to a unique trace log data set (TLDS) for this trace. If Y is specified with no additional summary or detail trace logging options, a single data set is allocated dynamically using the defaults specified in DMRBEXxx for this Db2. Note The BBI-SS PAS started task user ID must be authorized to use dynamic allocation.
   TITLE	c...c This value defines a title for the trace (1 to 24 characters). If you are logging the trace, BMC recommends that you specify a more specific title to help identify the contents of this trace at a later time.
   START	hh:mm:ss This value requests trace start time. If the time specified is more than 10 minutes prior to the current time, 24 hours are added to the specified time and the request is started the next day. To start a request at midnight, specify 24:00:00. The default is the next full minute.
   STOP	nnn | hh:mm:ss This value requests trace stop limit as a timestamp or number of minutes to process. The default is set from TRTIME in DMRBEXxx. Processing ends at the end of the last interval before the specified stop time. This time is displayed in the STOP field when the request is viewed with the R, P, M, and W line commands from the CT view.
   WRAP	Y | N The buffer is used in a wraparound method to store the entries and the wrap can be automatic, WRAP=Y (default), or user-controlled, WRAP=N.
   RST	HOT | PUR | QIS This value defines the restart option to be used when a service is quiesced because of an inactive Db2 subsystem or BLK=RRR (restart all monitors) request, as follows: HOT restarts the trace automatically without the loss of previous data. PUR purges the trace automatically when the target Db2 terminates. QIS keeps the trace in a quiesced state until it is purged by an authorized user. Note For dynamic or auto-connected targets, all traces are purged when the target terminates; the RST setting is ignored.

2. Request additional trace options by specifying Y for one of the following options:
   • Selection criteria - to select the transactions to be traced
   • Exception filters - to reduce the amount of data saved
   • Detail trace options - to trace additional events
   • Trace log data set options - to specify additional data set allocation and processing options
   • Additional trace targets - to start the same trace for multiple targets

3. Press Enter.If you specified Y for Selection Criteria or this is a detail trace, the DB2 Trace Selection Criteria dialog is displayed.

                            DB2 Trace Selection Criteria
    COMMAND ===>                                              SCROLL ===> CSR   
                                                                               
    Specify selection criteria:                                                 
     DB2PLAN  ____________________________________________________________      
     DB2AUTH  ____________________________________________________________      
     DB2CORR  ____________________________________________________________      
     DB2CONN  ____________________________________________________________      
     CONNTYPE ____________________________________________________________      
     DB2LOC   ________________________________________________________________  
              ________________________________________________________________  
     DB2PKG   ________________________________________________________________  
              ________________________________________________________________  
     DB2RTN   ________________________________________________________________  
              ________________________________________________________________  
     DB2ROLE  ________________________________________________________________  
              ________________________________________________________________  
                                                                               
    Specify End User Work Station Criteria:                                     
     DB2UID   ________________________________________________________________  
              ________________________________________________________________  
     DB2UTX   ________________________________________________________________  
              ________________________________________________________________  
     DB2UWN   ________________________________________________________________  
              ________________________________________________________________  
                                                                               
                                                                               
                                                                               
    ENTER to accept the selection criteria                                      
    HELP to view related help

4. To trace your own tests, and prefetch reads, specify your user ID and SYSOPR.

   DB2AUTH ==> userid ,SYSOPRYou can also specify other selection criteria when starting a trace. When starting a detail trace, you must specify at least one valid Plan (DB2PLAN) or Authorization ID (DB2AUTH) to limit Db2 tracing. This is subject to Db2 restrictions (1 plan /8 authids, or vice versa). For more information, see Selection-keywords.

   Note

   If you qualify by plan, prefetch read I/O events cannot be captured.

5. Press Enter.If you specified Y for Exception filters or this is a detail trace, the DB2 Trace Exception Filters dialog is displayed.

                            DB2 Trace Exception Filters
   COMMAND ===>                                              SCROLL ===> CSR
                                                                           
   Specify Exception Filters:                                               
   ELAP                        GETPAGE                   MAXLOCK            
   CPU                         PGUPD                     LOCKTBL            
   ABORT                       READIO                    INCRBIND           
   UIDCOM                      LOCKSUSP                  LOCKESCL           
   GETRIO                      RIDFAIL                   CLAIMDR            
   RLF                         TIMEOUT                   PWAITOT            
   PWAITIO                     PWAITLK                   PWAITPF            
   PFREQS                      PFREADS                   HPFAILS            
   PRLLRED                     PRLLFALB                  PRLLGRP            
   ELAPDB2                     CPUDB2                                       
                                                                           
   SQLTOT                      SQLSEL                    SQLFETCH           
   SQLUID                      SQLDYN                    SQLCTL             
   SQLDDL

   You can specify filters to discard thread accounting records that do not meet the qualification. The value can be a maximum (n) or a minimum (<n). For example, specifying ELAP ==> 10 only keeps threads with an elapsed time greater than 10 seconds. This filter is very useful when you are looking for poorly performing applications in an existing Db2 workload.

   Note

   If you specify several filters, they are ORed. A trace record is retained if any one of the comparisons is valid.

6. Press Enter.If you specified Y for Detail trace options or this is a detail trace, the DB2 Detail Trace Options dialog is displayed.

                             DB2 Detail Trace Options
    COMMAND ===>                                              SCROLL ===> PAGE  
                                                                               
    Specify additional events:                                                  
      SQL        Y (Y/N)                                                        
      SCANS      N (Y/N)                                                        
      I/O        N (Y/N)                                                        
      LOCKS      N (Y/N)                                                        
      DDF        N (Y/N)                                                        
      DDFVTAM    N (Y/N)                                                        
                                                                               
    Specify event compression:                                                  
      GROUP SQL  Y (Y/N)                                                        
                                                                               
    Specify data collection buffer options:                                     
      TRSIZE      400K     (Trace buffer size)                                  
      TRBUFF      20       (# of trace buffers)

   • GROUP SQL Y

     Y compresses many consecutive identical SQL statements together to save space and make the event trace easier to read; for example, combine many FETCHes.

   • TRSIZE (value shown is the default for your site)

     This value is the size of a data collection buffer. Without logging, the data collected for one thread is limited to two buffers. If you are tracing long-running applications, you might need to increase the size. With logging, multiple buffers can be written per thread and combined automatically when recalled online or printed.

   • TRBUFF

     You might need to increase this value to trace more concurrent threads or to provide multiple buffers for the logging of long-running applications. The recommended number is three or more times the number of concurrent threads to be traced.

     Note

     Using has additional recommendations that can help you trace special situations like capturing part of a long-running thread.

7. Specify the additional Db2 events that you want to trace.

   Parameter	Description
   SQL==> Y	Default is Y for standard application tuning.
   SCANS ==> Y	Default is N. Specify Y this time.
   I/O ==> Y	Default is N. Specify Y this time.
   LOCKS ==> N	Default is N. Leave as is - very expensive.
   DDF ==> N	Default is N. These events are needed only for distributed work.
   DDFVTAM ==> N	Default is N. These events are needed only for DDF VTAM analysis.

   Each of the other groups of events adds additional overhead. You can specify any combination; for example, SQL and I/O but not SCANS.

8. Press Enter.If you specified Y for Trace log data set options or this is a detail trace, the Trace Log Data Set Options dialog is displayed. Leave the default values.

                         Trace Log Data Set Options  
   COMMAND ===>                                              SCROLL ===> CSR
                                                                      MORE:
   Specify trace log data set options:                                      
   Number of logs    1                                                      
   First log DSN                                                            
               Low level qualifier of DSN must be V01                       
               Blank for default: BCVJXF3.DIT2.BLANK.mmmdd.Thhmm.V01        
               Names without quotes will be prefixed with BCVJXF3           
                                                                           
   Overwrite logs    Y        (Y/N) Action when all logs used               
   Archive PROC               (Blank for none or PROCLIB member name)       
   Log switch time            (HH:MM that a log switch is requested)        
                                                                           
   Disposition       NEW      (OLD/NEW) If NEW, specify options below       
                                                                           
   Volumes                                                                  
   Primary CYLS      3              SMS Storage class                      
   Data DSN Suffix   D               SMS Data class                         
                                     SMS Management class                   
                                                                           
                                                                           
   ENTER to accept the log dataset options

   Parameter	Description
   Number of Logs ==> 1	Multiple logs are usually needed only for continuous system traces for workload history.
   First Log DSN ==>	Leave this blank to take the generated default. You must be authorized for dynamic allocation of a trace log. See your system administrator. If you are not authorized, there is a batch job (JXT011) to preallocate a log data set. Type the name here and change Disposition to OLD.
   Overwrite Logs ==> Y	Y allows the latest trace data to be kept if it does not all fit in the log. N keeps the earliest trace data by quiescing the trace when full.
   Archive PROC ==>	Leave blank. This option is not needed for simple single-log traces.
   Log Switch Time ==>	Leave blank. This option is not needed for simple single-log traces.
   Disposition ==>NEW	Leave NEW unless you had to preallocate a log.
   Volumes ==>	This field should be filled in with the default volumes for your site. If not, specify a volume the BMC AMI Ops Monitor for Db2 product address space (BBI-SS PAS) is allowed to use.
   Primary Cyls ==>	Use the default.

9. If your site requires them and the defaults are not set, specify SMS values.SMS Storage Class ==>

   SMS Data Class ==>

   SMS Management Class ==>

10. Press Enter.When all extension dialogs are processed, the Start DB2 Trace Request dialog displays an asterisk (*) next to each processed option. The request is not submitted until all options display N or *. This feature gives you the opportunity to review and change your options before sending the request.