I am performing an Analysis of a CA Mainframe Application Tuner (MAT) Monitor and my DB2View display is showing mostly all zeros. Why?

Document ID : KB000020822
Last Modified Date : 14/02/2018
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Description:

The cause for these 0 values is in almost all cases the missing connection between the CA MAT DB2 Harvester and the DB2 subsystem. Very often the reason for the loss of the connection is the restart of the DB2 subsystem. There are several MODIFY commands that may help to check and solve this situation.

Solution:

DB2 Harvester lost connection to DB2 subsystem - many Performance metrics are 0.

It may happen from time to time, that during an analysis of a CA MAT measurement a display like shown below comes up:

CA MAT ---------------------- DB2View --------------------- Row 1 to 18 of 142
COMMAND ===>                                                  SCROLL ===> CSR 
                                                                               
Primary Commands: SQL (all/sampled), SEQ (sort), ADDHelp     Profile: CB05    
                                                             Options: NORMAL  
 Line commands:  S - Select SQL    E - Explain SQL               SQL: All     
                SD - Show Declare  I - Explain Information      Sort: Sequence
                 C - Code Details  D - Statement Detail     DB2 SSID: D2T1    
                                                             DB2 Rel: 10.1.0  
   DBRM or  D Data                   Call                            Total     
LC Package  S From Stmt Num Type     Count     Total CPU  CPU-P-Call Resp Time 
   ________ _ ____ ________ ________ _________ __________ __________ __________
>------------------------------------------------------------------------------
__ ZFF07    S S        2977 SELECT           0   0.000000   0.000000   0.000000
__ FO913    S S        5580 INSERT           0   0.000000   0.000000   0.000000
__ FOW04    S S        2859 SELECT           0   0.000000   0.000000   0.000000
__ FOW24    S S        2405 SELECT           0   0.000000   0.000000   0.000000
__ A4D00    S S        2794 INSERT           0   0.000000   0.000000   0.000000
__ A4D02    S S        6620 INSERT           0   0.000000   0.000000   0.000000
__ FOW29    S S        2787 SELECT           0   0.000000   0.000000   0.000000
__ FO931    S S        2897 INSERT           0   0.000000   0.000000   0.000000
__ DO434    S S         735 SELECT           0   0.000000   0.000000   0.000000
__ DEE10    S S        2362 FETCH            0   0.000000   0.000000   0.000000
__ FO964    S S        2899 OPEN             0   0.000000   0.000000   0.000000
__ FOW24    S S        2494 OPEN             0   0.000000   0.000000   0.000000
__ ZFU16    S S         447 SELECT           0   0.000000   0.000000   0.000000
__ FO200    S S         447 SELECT           0   0.000000   0.000000   0.000000
__ VV251    S S        2115 SELECT           0   0.000000   0.000000   0.000000
__ FOA29    S S        6190 OPEN             0   0.000000   0.000000   0.000000
__ FO964    S S        2940 FETCH            0   0.000000   0.000000   0.000000

The cause for these 0 values is in almost all cases the missing connection between the CA MAT DB2 Harvester and the DB2 subsystem. Very often the reason for the loss of the connection is the restart of the DB2 subsystem. There are several MODIFY commands that may help to check and solve this situation.

Display the actual status of the DB2 Harvester:

MODIFY MATUNER,HAR,LIST                                                    
TS0031I CA MAT Synchronous Data Gatherer System D925     is inactive.
TS0031I CA MAT Synchronous Data Gatherer Target D925DBM1 is inactive.
TS0031I CA MAT Synchronous Data Gatherer HVCode DB2E3    is inactive.
TS0031I CA MAT Synchronous Data Gatherer Server MATUNER  is inactive.
TN3431I Harvester command processed for: LIST 

Here MATUNER is the ServerID used in the startup of the CA MAT Started Task. The connection to the DB2 Subsystem D925 is inactive - either because no measurement using this subsystem has been executed or the communication to D925 has been lost because of the a restart of the DB2 subsystem.


Starting the DB2 Harvester connection for a specific subsystem:

MODIFY MATUNER,HAR,START,D925                                                  
TS0020I CA MAT Synchronous Data Gatherer Harvesting has been activated.   
MATUNER  START                                                            
TS0003I CA MAT Token = 1200C9B45469A9DF68945E5DB500000001340001           
TS0020I CA MAT Synchronous Data Gatherer Harvesting has been activated.   
MATUNER  START                                                            
TS0003I CA MAT Token = C300C9B45469A4DF68925E8A9700000001340001           
TS0019I CA MAT Synchronous Data Gatherer command processing completed.    
MATUNER  START    D925                                                    
TN3431I Harvester command processed for: START,D925

Now the LIST command is showing this status:

MODIFY MATUNER,HAR,LIST                                                  
TS0031I CA MAT Synchronous Data Gatherer System D925     is active.
TS0031I CA MAT Synchronous Data Gatherer Target D925DBM1 is active.
TS0031I CA MAT Synchronous Data Gatherer HVCode DB2E3    is active.
TS0031I CA MAT Synchronous Data Gatherer Server MATUNER  is active.
TN3431I Harvester command processed for: LIST

The best way to ensure the reinstating of the connection between DB2 Harvester and a restarted DB2 subsystem is to use System Automation to issue the appropriate CA MAT Modify command when the successful restart of the DB2 subsystem is recognized.