Dynamic transaction routing - IBM

In this case, the value of the TD Dynamic attribute is yes in the local definition for that transaction. Dynamic transaction routing enables you to define how a ... Dynamictransactionrouting Transactionroutingcanbeeitherstaticordynamic:Withstatictransactionrouting,thetransactionisrouted tothesystemthatisnamedwiththeRemoteSysIdattribute intheTransactionDefinitions(TD)for thattransaction.Inthiscase,thevalueoftheTDDynamicattribute isnointhelocaldefinitionforthattransaction. WithDynamictransactionrouting,thetransactioncanbe dynamicallyroutedtoanyavailablesystem,eitherremoteorlocal, whenthetransactionisstarted.Inthiscase,thevalueoftheTDDynamicattribute isyesinthelocaldefinitionforthattransaction. Dynamictransactionroutingenablesyoutodefinehowatransaction istoberouteddependingonsuchfactorsas:Inputtothetransaction AvailableCICS®systems Relativeloadingoftheavailablesystems Also,aroutingprogramcanperformotherfunctionsbesidesredirecting transactionrequests,suchas:Balancingofworkload.Forexample,inamultiple-CICSenvironment, yourprogramcouldmakeintelligentchoicesbetweenequivalenttransactions onparallelsystems. Handlingtransactionsthatcannotberouted,suchaswhennoremoteCICSregions areavailable. Handlingabendsintherouted-totransaction. Monitoringthenumberofrequeststhatareroutedtoparticular systems. DynamictransactionroutingcannotbeusedtorerouteremoteATI requests. CICSmanagesdynamictransactionroutingthrough theuseoftheCICS-supplieddynamictransactionroutinguserexit. Thisuserexitisinvoked:BeforeroutingatransactionthatisdefinedasDynamic=yes Ifanerroroccursinrouteselection Attheendofaroutedtransactioniftheinitialinvocationrequests reinvocationattermination Ifaroutedtransactionabendsandtheinitialinvocationrequests reinvocationattermination ParametersarepassedinastructurebetweenCICSand thedynamicroutingprogram.Theprogrammightchangesomeofthese parameterstoinfluencesubsequentCICSaction. Theparametersinclude:Thereasonforthecurrentinvocation. Errorinformation. Thenameofthetargetsystem.Initially,thisisthesystemthat isspecifiedwiththeTDRemoteSysIdattribute.Ifissystem isnotspecified,thenamethatispassedisthatofthelocalsystem. Thenameofthetargettransaction.Initially,thisisthename thatisspecifiedwiththeRemoteNameattribute.Ifatarget transactionisnotspecified,thenamethatispassedisthename ofthelocaltransaction. ApointertotheCWA. ApointertotheTCTUA. Auserarea. Adynamictransactionroutingprogrammustfollowstandarduser exitrules. CICSsuppliesasampleprogramthatcanbeinvoked bytheuserexit,butyoucanreplacethiswithoneofyourown.To dothis,defineyourprograminthePDoftheregionandsettheUserExitNumberattribute to25. AlthoughtheRemoteSysIdandRemotenameattributes areusedbythedynamictransactionroutinguserexitforrouting thetransactions,theyareignoredwhenthetransactionsarerunlocally. Ifyousetupthedynamictransactionroutinguserexittoallowa transactiontorunlocally,youneedtodefinethelocalprogram. Thisuserexitisnotinvoked:Whenthetransactionthatisdefinedasdynamicisstartedin anintermediateapplication-owningregion.CICSattempts toabendsuchtransactionsbutcannotdetectallattemptsto“daisy chain”dynamictransactions.Youmustensurethatyourdynamictransaction routingprogramdoesnot“daisychain”dynamictransactions. Whenaproblemoccursbecauseoflackofstoragewhiletheparameter listorstandardheaderfortheuserexitisbeingbuilt.Thiscauses thetransactiontoabend. WhenthedynamictransactionisstartedinaTerminal-OwningRegion byacommandofthefollowingtypethatisissuedinanApplication-Owning Region:EXECCICSSTARTTERM(yyyy)TRAN(xxxx) In thiscase,theuserexitisnotinvokedandthetransactionisrouted backtothesystemwheretherequestwasissued.