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THE Batch program performance issue on SVC008

 
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haohao

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Joined: 23 May 2008
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Location: beijing China

PostPosted: Fri Jun 05, 2009 12:29 pm    Post subject: THE Batch program performance issue on SVC008
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hello,everybody here!

I have a performance issue about a batch program. when the BATCH program
is running, about 80% of the running time is waiting. from IBM APA report as bellow:

Overall CPU Activity
Samples 60,000 100.0% ' ' ' ' ' ' ' ' ' ' '
CPU Active 6,423 10.7% ll
WAIT 51,027 85.0% lllllllllllllllll
Queued 2,550 4.2% l

then,I CHECK the wait time report, as bellow:
Code:

 W01: WAIT Time by Task/Category (0745/ESY100B2)             Row 00001 of 00021
                                                                               
 Name         Description         Percent of Time in WAIT * 10.00%   0.4%       
                                      *....1....2....3....4....5....6....7....8.
 IKJEFT01-001 TCB=008DC7D8      100.00 lllllllllllllllllllllllllllllllllllllllll
 IKJEFT02-006 TCB=008DC3D8      100.00 lllllllllllllllllllllllllllllllllllllllll
 IKJEFT09-007 TCB=008DC148      100.00 lllllllllllllllllllllllllllllllllllllllll
 DSN-008      TCB=008ACD50      100.00 lllllllllllllllllllllllllllllllllllllllll
 DSNECP10-009 TCB=008ACBB8       85.24 lllllllllllllllllllllllllllllllllllllllll
   SYSTEM       System/OS        49.04 lllllllllllllllllllllllll               
                Services                                                       
     SVC          SVC Routines   49.04 lllllllllllllllllllllllll               
       SVC008       LOAD         49.04 lllllllllllllllllllllllll               
         IEAVEWAT     Task       49.04 lllllllllllllllllllllllll               
                      management                                               
   DATAMG       Data Mgmt        28.13 llllllllllllll                           
                Processing                                                     
   DB2SQL       SQL Processing    7.93 llll                                     

the report shows that the SVC008 occupied the 50% of the waiting time.
from the ibm redbook, SVC008 is seems to be the system module to load the subprogram
into real storage. BUT it's very strange that the most of subprogram are static call by the
main program,so the subprogram should be link-edit into one loadmodule with the main program.
why so much LOAD still exist here? how can I reduce the waiting time?
I have no idea about that, so could anybody give me some suggestion?
thanks in advance!![/code]
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Bill Dennis

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Joined: 17 Aug 2007
Posts: 562
Location: Iowa, USA

PostPosted: Fri Jun 05, 2009 7:06 pm    Post subject:
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There are other modules being loaded on your behalf, for COBOL run-time and system subroutines.

Reducing the time might involve faster DASD, ensuring the libraries are in the Library Look Aside (LLA) list and other issues.
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Robert Sample

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Joined: 06 Jun 2008
Posts: 7931
Location: Bellevue, IA

PostPosted: Fri Jun 05, 2009 8:29 pm    Post subject:
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I'm not running APA, but from the manual (my emphasis added):
Quote:
Detail line descriptions

Each line represents a System Object - an object to which WAIT time is attributed. These lines are arranged hierarchically. You can expand a line (using the "+" line command) to reveal a breakdown into subordinate objects. Each type of object shown in this report is described here:
so your statement
Quote:
the report shows that the SVC008 occupied the 50% of the waiting time.
really should be that SVC008 and all subordinate tasks took 50% of the waiting time. This is a radically different statement from what you claim -- and task management, for example, is one of those subordinate tasks. I think you're jumping to conclusions with inadequate data -- you need to look at everything included in the SVC008 number to know for sure what's eating up the time. The actual LOAD from disk could be a small fraction of the total.
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haohao

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Joined: 23 May 2008
Posts: 35
Location: beijing China

PostPosted: Sat Jun 06, 2009 7:52 am    Post subject:
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actually,the SVC008 NODE only has this IEAVEWAT subtask.
this is the fullly expand view from APA W01 report:
Code:

DSNECP10-009 TCB=008ACBB8 85.24 *******************************************
> SYSTEM System/OS 49.04 *************************
Services
> SVC SVC Routines 49.04 *************************
> SVC008 LOAD 49.04 *************************
> IEAVEWAT Task 49.04 *************************
management
> IGC001 Supervis 49.04 *************************
or
Control
> DATAMG Data Mgmt 28.13 **************
Processing
> GLCPARAM VSAM 28.13 **************
> POINT UT0145+FFE 28.13 **************
> IDA019L1 Virtual 28.13 **************
I/O (VIO)
and VSAM
> IDA019R3 Virtual 28.13 **************
I/O
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haohao

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Location: beijing China

PostPosted: Sat Jun 06, 2009 10:13 am    Post subject:
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from another report from APA,shows that over 30% disk I/O on LE load
library CEE.SCEERUN,show as bellow:

Code:

 D03: DASD Usage Time by Dataset (0743/ESY100B1)             Row 00001 of 00007
                                                                               
 Dataset Name>DDName                   Percent of Time * 10.00%   1.2%         
                                           *....1....2....3....4....5....6....7
 CEE.SCEERUN                          38.10 lllllllllllllllllll               
   STEPLIB    1P1RS2                  38.10 lllllllllllllllllll               
                                                                               
 BANCS.FNETLVEK.GLCPARAM              18.75 lllllllll                         
 BANCS.FNETBTCH.LOAD.DBIO              5.73 lll                               
 BANCS.FNETBTCH.LOAD.SUBPROG           3.31 ll                                 
 BANCS.FNETBTCH.LOAD                   3.08 ll                                 
   

it is very strange that why so much I/O on LE library. this libry is
already added to LINKLIST:
Code:

 ********************************* TOP OF DATA *****************************
57  12:36:13.00             ISF031I CONSOLE BAAP127 ACTIVATED             
57  12:36:13.00            -D PROG,LINKLIST                               
57  12:36:13.05             CSV470I 12.36.13 LNKLST DISPLAY 197           
                            LNKLST SET LNKLST06   LNKAUTH=LNKLST           
                            ENTRY  APF  VOLUME  DSNAME                     
                               1    A   1P1RS1  SYS1.LINKLIB               
                               2    A   1P1RS1  SYS1.MIGLIB               
                               3    A   1P1RS1  SYS1.CSSLIB               
                               4    A   1P1RS1  SYS1.SIEALNKE             
                               5    A   1P1RS3  SYS1.SIEAMIGE             
                               6    A   CP1CT1  SYS1.RACF.LINKLIB.NORMAL   
                               7    A   CP1CT1  SYS1.PLEXP1.LINKLIB       
                               8    A   1P1RS3  ASM.SASMMOD1               
                               9        1P1RS2  CEE.SCEERUN2               
                              10    A   1P1RS2  CEE.SCEERUN               
                              11    A   1P1RS3  CBC.SCCNCMP             
 
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Bill Dennis

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PostPosted: Mon Jun 08, 2009 8:03 pm    Post subject:
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Is the library also in your STEPLIB?
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haohao

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PostPosted: Tue Jun 09, 2009 6:01 am    Post subject:
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sure,the CEE LIBRY is in my job's step libry. what's the matter?
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haohao

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PostPosted: Tue Jun 09, 2009 7:02 am    Post subject:
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hi ,Bill:
I remove the CEE libry from the steplib ,the I/O on CEE is reduced almost to zero,now the batch program's preformance is imporved about 50% .
but would you please explain why ?
what I must pay attention to when I code the batch JCL steplib?
is it always better to remove all libraries in JOB STEPLIB who are already existed in LINKLIST?

thank you very much!!
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