This chaptercontainsthefollowingsections:
v “Dataavailablefor aCICS-DBCTLsystem”
v “MonitoringDBCTL—transactionleveldata”onpage 150 v “TuningaCICS-DBCTLsystem”onpage158
Note: InCICSandIMS,thetermstatisticsmeansdataproduced concerning timingandresourcesusedbythesystemasawholeoveraspecifiedperiod oftime.Additionally,inCICS,monitoringmeansdataproduced concerning timingandresourcesusedbyataskor alogicalunit ofwork(UOW).IMS doesnotmakethisdistinction—alldata returnedisreferredto asstatistics.
Here,weusethetermsstatisticsandmonitoringintheCICSsense.
For programminginformationonmonitoringinCICS,seethedfha300l;.For informationonstatisticsandonCICSperformancetuning,seetheCICS
PerformanceGuide.For informationonIMSperformanceandtuning,seetheIMS SystemAdministrationGuideor theIMS/ESAAdministrationGuide:System.
Data available for a CICS-DBCTL system
As withyour CICSor IMSsystem,observingtheperformanceof DBCTLinvolves collecting andinterpretingdatagatheredbyvariousCICSandIMSperformance tools.ThedifferencewithDBCTListhatyouneedto keepaneyeoneventstaking placeinseparateaddressspaces.Figure48onpage148givesanoverviewof whereDBCTLmonitoringandstatistics dataissenttoandthetoolsyoucanuseto produceoutputfromthisdata.Thedataandtoolsmentionedaredescribedinthe sectionsthatfollow.
DBCTL statistics
DBCTLsuppliesCICSwithstatistics informationwhenCICSdisconnectsfrom DBCTL.Theseareknownasunsolicitedstatistics,becausetheyarenotproduced aspartofnormalinternalprocessing,butareproduced asa USSstatistics record.
Thestatistics arewrittento SMFregardlessof thestatusof statisticsrecording.
CICS-DBCTLstatisticsarecollectedwheneverDBCTLisdisconnectedasaresult of:
v AnorderlyorimmediatedisconnectionofDBCTL v AnorderlyterminationofCICS
CICS-DBCTLstatisticsarenotcollectedifthere isanimmediateshutdownor abendof CICS.
CICS monitoring facility reports
CICS statistical reports
RMF reports
SLR output
IMS monitor output
DFH$MOLS DFHSTUP RMF SLR DFSUTR20
utility MVS
CICS DRA DBCTL
DFHMNDUP
SMF
IMS log X'07' record X'08' record X'45' record
IMS monitor data set
Figure48.OverviewofDBCTLstatisticsandmonitoringdata
Whenstatistics arecollected, thefollowing happens:
1. TheDRAreturnsstatistics fortheCICS-DBCTLsessionthathasjustendedto DFHDBAT.
2. DFHDBATinvokestheCICSstatisticsexit forDBCTLstatistics (DFHDBSTX).
3. DFHDBSTXinvokestheCICSstatistics domain.
4. TheCICSstatisticsdomainwritesthestatistics totheSMFdataset.
CICS-DBCTLsessionstatistics arecontainedintheDFHDBUDSDSECT,whichyou can generatefromthecopybookDFHDBUDS. DFHDBUDSincludesthefollowing information, whichisreturnedfromtheDRAforthatCICSsession:
v DBCTLidentifierfortheCICS-DBCTLsession(STATDBID).
v DBCTLrecoverable serviceelement(RSE)name(STARSEN).(Formore informationaboutRSEs, seeChapter6, “Recoveryandrestartoperationsfor DBCTL,”onpage73.)
v TimeCICSconnectedto DBCTL(STACTIME).
v TimeCICSdisconnectedfromDBCTL(STADTIME).
v Minimumnumberof threadsspecifiedintheDRAstartuptable(STAMITHD).
v Maximumnumberof threadsspecifiedintheDRAstartuptable(STAMATHD).
v Numberof timesthattheCICS-DBCTLsession“collapsed”threadsdowntothe minimumthreadvaluespecifiedintheDRAstartuptable(STANOMITHD).
v Numberof timesthattheCICS-DBCTLsessionreachedthemaximumthread valuespecifiedintheDRAstartuptable(STANOMATHD).
v Elapsedtime,expressedinhours,minutes,andseconds,forwhich the CICS-DBCTLsessionranat themaximumthreadvalue(STAELMAX).
v Peaknumber(alsoknownasthe“high-watermark”)ofthread TCBscreated throughouttheCICS-DBCTLsession(STAHIWAT).
v Totalnumberof timesthis CICS-DBCTLsessionsuccessfullyscheduleda PSB (STAPSBSU).
For informationonDBCTLstatisticsseetheCICSPerformanceGuide.
Toextractandprintareport fromthesestatistics,runtheCICS-suppliedstatistics utility program(DFHSTUP),specifyingthespecificAPPLIDof therelevantCICS system.TheoutputwillincludeCICS-DBCTLsessionstatistics providedDBCTL wasconnectedto CICSwhenthestatisticswere collected.Forinformationabout other parametersneededto runDFHSTUP,andasample jobstreamyoucanuse, see theCICSOperationsandUtilitiesGuide.Figure49showsanexampleof a reportproduced byrunningDFHSTUP.
Note: Thestatisticsreportproduced byrunningDFHSTUP(showninFigure49) displaysthetimesatwhichCICSconnectedto anddisconnected from DBCTLinhours,minutes,andseconds(hhmmss)format inlocal time.The DBCTLUSSrecord mappedbytheDFHDBUDSDSECTcontainsthe connectanddisconnecttimesasfour8-bytestoreclock(STCK)values.
Theseare:connect anddisconnecttimeexpressedinlocaltimeandconnect anddisconnecttime inGreenwichMeanTime(GMT).
CICSstatistics thatcontainthenumberof DL/Irequests bytype, issuedagainst each DL/Idatabasearenot producedbyCICSintheDBCTLenvironment.Instead, DBCTLproducesthis typeofinformation.You canobtainDBCTLbufferpool utilization informationfromtheDBCTL/DISPLAYcommand,orfromtheIMSlog recordsof typeX'45'.
Monitoring DBCTL—transaction level data
Monitoringdatafor DBCTLispassedto CICSandIMScomponents.(SeeFigure48 onpage148.)SeetheCICSOperationsandUtilitiesGuideforhelp onswitching monitoringon,andonprintingandformattingthedata.
This sectioncovers:
v “DBCTLmonitoringdatareturnedto CICS”
v “IMSmonitorreportswithDBCTL”onpage153
v “DatacontainedinrelevantIMSmonitorreports”onpage153 v “Regionsandjobnamereport”onpage154
v “Regionsummaryreport”onpage 154
v “DBCTLdatareturnedto IMSlog”onpage156 v “DL/Itrace” onpage156
v “Tracefacilities”onpage 157
v “Additionalperformancetools”onpage157
DBCTL monitoring data returned to CICS
Monitoringdataat thetransactionlevelispassed backto CICSbyDBCTL wheneveraTERM requestoccurs,eitherexplicitly,orimplicitlyattheendoftask termination.ThedataisappendedtotheCICSmonitoringfacilityperformance record oftheissuingtask.Thedatareturnedisasfollows:
v PSBname.
Unsolicited StatisticsReport CollectionDate-Time 09/16/93-15:16:18 Last Reset 15:06:46 Applid IYAHZCD2 JobnameCI13JTD5 ---DBCTLSESSION TERMINATION STATISTICS
---CICS DBCTLSession Number : 2
DBCTLidentifier : SYS2
DBCTLRSE name : DBCTLSY2
Time CICS connectedto DBCTL :15:14:02.8506 Time CICS disconnectedfrom DBCTL:15:16:18.3689
Minimum number ofthreads : 1
Maximum number ofthreads : 3
Timesminimum threads hit : 1
Timesmaximum threads hit : 1
Elapsed timeat maximum threads :00:00:09.4371
Peak number of thread TCBs : 3
SuccessfulPSB schedules : 9
Figure49.ExampleofCICS-DBCTLsessionstatisticsoutput
v Elapsedwaittimeforpoolspace. InaPSBschedule,whenthepoolspaceis insufficientfor PSB/DMBblocks,theschedulerequestisputona waitqueue.
Thetotalwaittime forit isinthisfield.
v Elapsedwaittimeforintentconflict.InaPSBschedule,whenanintentconflictis detected,theschedulerequestisputonawaitqueue.Thetotal waittimefor itis inthis field.
v Elapsedtimefor theschedulerequest.
v ElapsedwaittimefordatabaseI/O.
v Elapsedwaittimeforlocking.Thetotal waittime togetthePIlockswhichare localsegmentlevellocks.
v Totalnumberof databaseI/Ocounts.
v Numberof DL/Irequestsfor eachof thefollowing:
Getunique Getnext
Getnext withinparent Gethold unique Gethold next
Gethold nextwithinparent Insert requests
Deleterequests Replacerequests
v Totalnumberof DL/Idatabaserequests.
v Numberof testenqueues.
v Numberof timesrequestingthePIlocksonsegments.
v Numberof waitsontestenqueues.
v Numberof timesrequestingthePIlocksonsegments.
v Numberof dequeues.
v Numberof timesPIlocksarereleased.
v Numberof updateenqueues.
v Numberof timestheupdatelocksarenotavailablefor arequestandrequiresa wait.
v Numberof updatedequeues.
v Numberof timesrequestingtheexclusivelock.
v Numberof waitsonexclusiveenqueues.
v Numberof timestheexclusivelocksarereleased.
v Numberof exclusivedequeues.
v Numberof timestheexclusivelocksarereleased.
v DEDBstatistics:
Numberof DEDBrequests Numberof DEDBI/Os
Numberof overflowbuffersused Numberof waitsforDEDBbuffer Numberof unitofworkcontentions v Dateof schedulestart.
v Timeofschedulestart.
v Dateof scheduleend.
v Timeofscheduleend.
v ElapsedUOWCPUTIME forDRAthread(see notebelow).
Note: TheelapsedCPUTIME fieldwasintroducedbyIMSAPARPL83370.The CPUTIMErepresentsthetimespentintheDRAThreadTCBfromthetime thePSBisscheduled,tothetimethePSBisterminated.CICSalways terminatesthePSBattheendoftheUnitofwork(UOW).TheCPUTIME doesnotinclude anytimespentintheDBCTLregion.
Obtaining DBCTL monitoring data sent to CICS
DBCTLsuppliesCICSwithmonitoringdata,which isthenoutputtotheCICS monitoringdomaininthefollowingcases:
v WhenCICSreceivestheresponsetoa PSBschedulerequestfromDBCTL,it checkswhether thistaskhasalready beenscheduledsuccessfullytoDBCTL.If it has,CICSforcesthemonitoringdatafromthepreviousPSBscheduleout;that is,itwritestheperformanceclassrecord forthetaskandresumes monitoring thattask.If ithasnotbeenscheduled before,nomonitoringprocessingisdone.
v WhenCICSreceivesa responsefromtheDBCTLasa resultof aCOMMITor ABORTrequest,CICSoutputsthemonitoringdata, butdoes notwriteit.
v InthecaseofthefinalPSBschedulefor atask,themonitoringdatais automaticallywrittenat theendof atask.
ToobtainthemonitoringdatathatDBCTLreturnstoCICS,code twoadditional eventmonitoringpoints(EMPs)inyourCICSmonitoringcontroltable(MCT).
DBCTLEMPscanbefoundinCICSTS23.CICS.SDFHSAMPmemberDFH$MCTD.
For programminginformationonEMPs,andtheformat ofmonitoringrecords,see theCICSCustomizationGuide.
When youhaveobtainedthemonitoringdata,youcan usemonitoringtoolssuchas theCICSmonitoringfacilityandtheServiceLevelReporter(SLR)withthedata suppliedto tuneyourCICS-DBCTLenvironment.SeetheCICSCustomization Guidefor programminginformationonusingtheCICSmonitoringfacility.
Service Level Reporter (SLR)
ServiceLevelReporter(SLR)isanIBMdatabaseandreportingprogramthat collectsandanalyzesdatafromCICSandotherIBMsystemsandproducts.SLR collectsCICSdatafromCICSmonitoringrecordsandfroma subsetofCICS statistics ontheSMFlogdataset.Itthenanalyzesthedata,summarizesthe results, andstoresthedataintheSLRdatabase.
TheDBCTLdataintheCICSmonitoringrecordsisoutputasone256-byteblock, andiswrittenbytheEMPDBCTL.2,asdefined inCICSTS23.CICS.SDFHSAMP memberDFH$MCTD. TheDSECTforthis256-byte blockofdataismappedbythe DFSDSTAmacrointheIMSGENLIBs.TheSLRtablesCICSTRANSLOGand CICSTRANSNUMcontainthefieldsinthisblock.
During SLRinstallation,you mustspecifywhetheryouwantDBCTLdata.For guidanceontheformatofthis data,seethedescriptionof theDFSDSTAmacroin theappropriateIMS/ESACustomizationGuide.ForinformationonSLRdatain CICSandIMS,seetheIMSSystemAdministrationGuideor theIMS/ESA
AdministrationGuide:System.For helponusingSLR, includingexamplesofSLR reportsandhowto makeuse ofthem,see theServiceLevelReporterVersion3 General Informationmanual.
Note: Thereisafollow-onproducttoSLR, calledPerformanceReporter forMVS, whichhasDB2asa prerequisite.Thisproductincludesthefunctionsthatare
carriedoutbySLR. PerformanceReporterfor MVSCICSPerformance FeatureGuideandReference, SH19-6820,describesthewaythisproduct workswithCICS.
IMS monitor reports with DBCTL
This sectionsummarizesDBCTL-relateddata inIMSmonitorreports.(This informationalso appliesif yourCICSsystemisconnectedtoanIMS/ESADM/TM system toobtainDBCTLsupport.)
IMS monitor reports that apply to DBCTL
v Callsummary v ProgramI/O v DBbufferpool v VSAMbufferpool v Programsummary
Note: Ina DBCTLenvironment,interprettheterms “program”and“transaction” in thesereportsas“PSB”and“PSBscheduling”,respectively.
IMS monitor reports that apply partially to DBCTL
v Regionsummary v RegionIWAIT
(AnIWAIToccurswhenaDBCTLrequestcauses I/Oactivity.IWAITtime denotesthetimeDBCTLspendswaitingfor IMSresources,inadditionto the numberofI/Os.)
v Anyotherregionbasedreports.
Note: Ina DBCTLenvironment,interprettheterm“region”inthesereportsasthe representationofaCICSthread oraBMPregioninDBCTL, butbeware that aDBCTLregionmay representdifferentCICSthreadsor BMPregions duringamonitorrun.
IMS monitor reports that do not apply to DBCTL
Thefollowingreports,relatedtotransactionmanagement andcommunication,do notapplytoDBCTL, andeitherdonotappear,or areshownasheadingswithout any data:
v Communicationwait v Communicationsummary v Linefunctions
v Messageformatbufferpool v Messagequeuepool v MSCqueuingsummary v MSCsummaries v MSCtraffic
Data contained in relevant IMS monitor reports
This sectiontellsyouwhatkind ofdatayoucan findintheIMSmonitorreportsthat applyto DBCTL.
General wait time events
Allthreadsbuiltfor aCICSsystemhave thesamejobnameasthatCICSsystem.
They areshown inthejobnamesforregionsinthe“Generalreports”.
General reports
The“generalreports”includethe“Regionsandjobname”reportandthe“Region summaryreport”.
Regions and jobname report
Withinatrace interval,athread canbeassignedto multipleCICSsystemsbutit can onlybeassignedtooneCICSatanyonetime. So,dependingonthenumber of CICSsystemsconnectedtoDBCTL,theregionsandjobnamereportcan show:
v Oneregionwithonly onejobname.
v Oneregionwithmultiplejobnames.
v Multipleregions withmultiplejobnameswheresomeregionshavethesame jobname,andsomehavemultiplejobnames.
v Multipleregions withonly onejobname.
Anymonitorreportfor aregionisa summaryfor allconnectedCICSsystemsthat a threadhas servedduringthetraceinterval.For example,theelapsed timeof scheduleendto firstcallmeansthesumof thiselapsedtime forallCICSsystems thata threadhasbeen assignedto duringthetraceinterval.
Depending ontheworkloadof aCICSsystem,atrace intervalmaybearelatively short periodof time,andthread switchingbetweendependingregions maynot occurveryoften. However,themoretheworkloadfluctuates,themorefrequently threadsarelikelyto beassignedamongst connectedCICSsystems.
Region summary report
Aregionsummaryreportcanshow:
v Schedulingandtermination,including:
– Thetime fromPSBschedulerequestbeingreceivedbyDBCTLtowhenthe requestiscompletedbyDBCTL.ThisincludesthetimespentbyDBCTL allocatingIMSresourcesanddoes notinclude anyscheduletimespentin CICSor beingprocessedbytheDRA.
– Thetime fromwhena PSBunschedulerequestisreceivedbyDBCTLto whentherequestiscompletedbyDBCTL.Thisrequestcouldbean
unschedulePSBrequest,ora requestimbeddedinanysynchronizationtype terminaterequest,ora terminatethreadrequest.
v Scheduleto firstcallisthetime fromwhenDBCTLcompletedthePSB scheduletowhenDBCTLreceivedthefirstDL/Irequest.Thistime includesall timespentprocessinginCICS,includingapplicationprogram,CICSitself,and DRAprocessing.(BecauseCICSisthetransactionmanager,how andwhenits ownapplicationsareloadedorscheduledcannotbeinterpretedbyDBCTLinthe IMSmonitorreports.)
v Elapsedexecutionisthetimebetweenthecompletion oftheDBCTLPSB schedulerequestandwhenDBCTLreceivesthePSBunschedulerequest.It indicatestheamountoftimeIMSresourceswereallocatedtoa CICSthread.
v Regionoccupancyistheratioof theelapsedtimewhenathread isactive(that is,withIMSresourcesallocated)tothetraceinterval.
v DL/IcallsisthetimebetweenDBCTLreceivingtheDL/Irequestandtherequest beingcompleted inDBCTL.
Program summary
DBCTLdoesnotprocess anymessages.Forthepurposeof usingtheDCmonitor report, itcountseach PSBscheduleasonemessagedequeued.BecauseDBCTL isnotthetransactionmanager,it hastoassume aone-to-onerelation betweena CICStransactionanda PSBschedule.This isshown inprogramsummary, where thenumberoftransactionsdequeuedisthesameasthenumberof scheduled
requests.“Pertransaction”meansrequests perschedule,and“elapsed timeper transaction” meanselapsed timeperschedule.
Run profile
In runprofile,thenumberof messagesdequeuedmeansthenumberofscheduled PSBs andtransactionspersecondmeansPSBschedulespersecond.
Transaction queuing report
This reportcanincludea listof“transactions”forDBCTL. Eachtransactionnameis an8-bytetransactionIDspecifiedbyCICSontheschedulerequest.Atransaction IDfromCICScomprisesof a4-byteCICStransactionname,plusa 4-byteCICS identifier.If CICSdoes notspecifyatransaction ID,DBCTLtakestheCICSregion ID, obtainedatconnection time.In thisreport,for DBCTL,thetransaction“number dequeued”meansnumberofPSBschedules.The“onqueuewhenscheduled”in this reportisalwayszerobecausetheIMSmessagequeuesdonotapplyto DBCTL.
For examplesofIMSmonitorreportsanddetailed guidanceoninterpretingtheir contents,seetheIMSUtilitiesReference:Databasemanualmanual.
Using the IMS monitor
DBCTLenablesCICSuserswhodonothave anIMS/VSDB/DCor
IMS/ESA/DM/TMsystem tousetheIMSmonitoronline.TheIMSmonitoristhe main toolprovidedbyIMSformonitoring.Itcollectsdatafromthesystem whileitis running.It formatsandrecordssignificanteventsduringexecution,andisusefulin tuningconstrained systems.
Monitoringdataiswrittento aseparatedatasetor tapedefinedbytheIMSMON DDstatementintheDBCTLJCL.Todefinethisdatasetortapeandto runtheIMS monitorwithDBCTL,addanIMSMONDDstatementto yourDBCTLJCL.For further guidanceondoingso,seetheIMSSystemDefinitionReferencemanual manualor IMS/ESAInstallationVolume 2:SystemDefinitionandTailoring.
ToallocateanIMSMONdataset,usetheIEFBR14utilitytoallocateadataset without anyDCBparameters;for example:
//ALLOC EXEC PGM IEFBR14
//IMSMON DD DISP=(NEW,CATLG),UNIT=3380,VOL=SER=xxxxxx,SPACE=(CYL,(5,5))
You canstartandstoptheIMSmonitordynamicallyusingthe/TRACEcommand withtheMONkeyword.Forexample:
/TRACE SET ON MON ALL
givesyoualltheactivitythatthemonitorcollects.Forguidanceonusingthe /TRACEcommandanditskeywordsmoreselectively,seetheIMSOperator’s Referencemanual.
TheIMSmonitorhastwophases:
v Duringthefirstphase,themonitorprograms collectthedataandstoreit on
v Duringthefirstphase,themonitorprograms collectthedataandstoreit on