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Manage active and prepared transactions by

We can use wsadmin scripting to manage active and prepared transactions that might need administrator action.

Before starting, the wsadmin scripting client must be running.

In normal circumstances, transactions should run and complete (commit or roll back) automatically, without the need for intervention. However, in some circumstances, we might have to resolve a transaction manually. For example, you might want to roll back a transaction that is stuck polling a resource manager that you know will not become available again in the required time frame.

(zos) In normal circumstances, every effort is made to finish a transaction. However, because of Resource Recovery Services (RRS) and native contexts finishing, it might not be possible to finish the transaction. In this case, the transaction is marked rollback_only so that it rolls back at the next available window. In other situations, we might have to finish a transaction manually. For example, you might want to finish a transaction that is stuck polling a resource manager that you know will not become available again in the required time frame.

If we choose to complete a transaction on an application server, it is recorded as having completed in the transaction service logs for that server, so it is not eligible for recovery during server start up. If we complete a transaction, you are responsible for cleaning up any in-doubt transactions on the resource managers affected.

For more information about the TransactionService and Transaction MBeans, see the (API) documentation.


Example

The following script is an example of how to use the TransactionService and Transaction MBeans to work with manual transactions. Run the script only against an application server, and not against the deployment manager or node agent.

Example Jacl script: 

# get the TransactionService MBean
set servicembean [$AdminControl queryNames type=TransactionService,*]
 # get the Transaction MBean
set mbean [$AdminControl queryNames type=Transaction,*]
 set input 0
while {$input >= 0} {
        # invoke the listManualTransactions method         set tranManualList [$AdminControl invoke $servicembean listManualTransactions]
         if {[llength $tranManualList] > 0} {
                puts "----Manual Transaction details---------------"
                set index 0
                foreach tran $tranManualList {
                        puts "   Index= $index tran= $tran"
                        incr index
                }
                puts "----End of Manual Transactions ---------------"
                puts "Select index of transaction to commit/rollback:"
                set input [gets stdin]
                if {$input < 0} {
                        puts "No index selected, exiting."
                } else {
                        set tran [lindex $tranManualList $input]
                        set commaPos [expr [string first "," $tran ]-1]
                        set localTID [string range $tran 0 $commaPos]
                        puts "Enter c to commit or r to rollback Transaction $localTID"
                        set input [gets stdin]
                        if {$input=="c"} {
                                puts "Committing transaction=$localTID"
                                $AdminControl invoke $mbean commit $localTID
                        }
                        if {$input=="r"} {
                                puts "Rolling back transaction=$localTID"
                                $AdminControl invoke $mbean rollback $localTID
                        }
                }
        } else {
                puts "No Manual transactions found, exiting"
                set input -1
        }
        puts " "
 }

Example Jython script: 

import sys
def wsadminToList(inStr):
        outList=[]
        if (len(inStr)>0 and inStr[0]=='[' and inStr[-1]==']'):
                tmpList = inStr[1:-1].split(" ")
        else:
                tmpList = inStr.split("\n")  #splits for Windows or Linux
        for item in tmpList:
                item = item.rstrip();        #removes any Windows "\r"
                if (len(item)>0):
                        outList.append(item)
        return outList
#endDef
 servicembean = AdminControl.queryNames("type=TransactionService,*" )
mbean = AdminControl.queryNames("type=Transaction,*" )
input = 0
 while (input >= 0):
        tranList = wsadminToList(AdminControl.invoke(servicembean, "listManualTransactions" ))
         tranLength = len(tranList)          if (tranLength > 0):
                print "----Manual Transaction details---------------"
                index = 0
                for tran in tranList:
                        print "   Index=" , index , " tran=" , tran
                        index = index+1
                #endFor                  print "----End of Manual Transactions ---------------"
                print "Select index of transaction to commit/rollback:"
                input = sys.stdin.readline().strip()
                if (input == ""):
                        print "No index selected, exiting."
                        input = -1
                else:
                        tran = tranList[int(input)]
                        commaPos = (tran.find(",") -1)
                        localTID = tran[0:commaPos+1]
                        print "Enter c to commit or r to rollback transaction ", localTID
                        input = sys.stdin.readline().strip()
                        if (input == "c"):
                                print "Committing transaction=", localTID
                                AdminControl.invoke(mbean, "commit", localTID )
                        #endIf                          elif (input == "r"):
                                print "Rolling back transaction=", localTID
                                AdminControl.invoke(mbean, "rollback", localTID )
                        #endIf                          else:
                                input = -1
                        #endelse
                #endElse          else:
                print "No transactions found, exiting"
                input = -1
        #endElse          print " "
 #endWhile


Related tasks

  • Manage active and prepared transactions
  • Start the wsadmin scripting client

  • Transaction service settings
  • Additional APIs