How To Use The Same TSO USERID In a Shared Environment                      
               (last update 05/06/2014)                                         
                                                                                
 GRS / MIM Considerations:                                                      
                                                                                
 If you are using GRS or MIM (you should be using one of them in a              
 shared environment) you must not propagate the SYSIKJUA QNAME or you           
 will see message IKJ56425I (which indicates you are already logged             
 on) when you try and logon to a second system.  Note that the TSO/E            
 General Information manual says that propagation of this QNAME is              
 required for TSO Generic Resource support in a parallel sysplex. In            
 a shared environment, you should already be propagating the SPFEDIT            
 QNAME which is used by ISPF to preserve data set and PDS member                
 integrity.                                                                     
                                                                                
                                                                                
 JES2 Considerations:                                                           
                                                                                
 For using a single TSO USERID in a JES2 MAS, a JES2 source update              
 to HASPCNVT is required (this takes care of the duplicate logon                
 check in JES2).  Alternatively, JES2 exit 44 can be used.  If only             
 the DASD is shared and there is no JES2 MAS involved, then the JES2            
 source update or exit is not required.  In z/OS 1.4 and above, the             
 JES2 HASPCNVT modification is no longer required.                              
                                                                                
 Also note that when using NOTIFY=USERID in a JES2 MAS, the job                 
 completion message will be sent to the system that has the USERID              
 with the lowest job number.  In practice this will be the same as              
 the first system you logon to. This issue is resolved in z/OS 1.13             
 when all participating MAS members are at that level (or above).               
                                                                                
                                                                                
 SDSF Considerations (sysplex only):                                            
                                                                                
 When using a single TSO USERID in a sysplex, no modifications to               
 SDSF are required. However, if you use the ULOG command or issue               
 MVS and JES2 commands, you will only see the responses on the first            
 system that activates the EMCS console. This is because there can't            
 be more than one console in a sysplex with the same name, and the              
 default EMCS console name is your USERID.  You can change your SDSF            
 EMCS console name by using the "SET CONSOLE <name>" command or from            
 the "Options" pull down menu. I normally suffix my USERID with a               
 unique single letter or number on each system.                                 
                                                                                
                                                                                
 JES3 Considerations:                                                           
                                                                                
 For using a single TSO USERID in a JES3 complex a JES3 source                  
 update to IATGRJS is required (this takes care of the duplicate                
 logon check in JES3). If only the DASD is shared and there is no               
 JES3 complex involved, then the JES3 source update is not required.            
 However, as of z/OS 2.1, the JES3 source usermod is no longer                  
 required for any JES3 configuration as there is no longer any                  
 duplicate logon check within JES3.                                             
                                                                                
                                                                                
 ISPF Considerations:                                                           
                                                                                
 1) Prior to z/OS 1.9, the LOGON clist must allocate a different                
 ISPF profile for each system.                                                  
 I use:  userid.SYSnnnn.ISPPROF (nnnn=SMFID).                                   
                                                                                
 Starting at z/OS 1.9, profile sharing is possible. You must at least           
 set PROFILE_SHARING=YES in the ISPF configuration table.  In the               
 ISPCCONF dialog, this can be found as "Multi-logon Profile Sharing"            
 in the "ISPF Site-wide Defaults" section. If you are already using             
 the setting for ISPF_TEMPORARY_DATA_SET_QUALIFIER, you may remove it           
 and let it default to "ISP&SEQ" (see below for more on this for pre-           
 z/OS 1.9 systems). If you don't remove the qualifier setting or                
 specify the default of ISP&SEQ, you will get a warning, but you can            
 ignore it as long as the setting will resolve to something that is             
 unique for each system in the sysplex, for example SYS&SYSNAME.  See           
 the "Profile Sharing" section in the ISPF Planning and Customization           
 manual for more information on this. ** Note that using the ISPF               
 plugin of z/OS Management Facility (z/OSMF) for z/OS 1.13 and                  
 above requires the use of profile sharing to allow multiple ISPF               
 sessions.                                                                      
                                                                                
 The information below applies to ISPPROF sharing without the                   
 sharing support introduced in z/OS 1.9 enabled:                                
                                                                                
 There are some shops that share ISPPROF by not propagating the                 
 ENQ for SPFEDIT specifically for the profile data set name.                    
 Masking must be used with GRS / MIM for the ENQ RNAME in this case.            
 I don't recommend this approach because it could lead to corruption            
 of your profile data set.  The other caveat with this approach is              
 that because the same profile member (APPL) could be updated from              
 multiple systems concurrently, the last update wins. For example,              
 if you are logged on to SYSA and SYSB and update a PFK setting                 
 from SYSA and then logoff SYSA before SYSB, you will lose that                 
 update.  This same issue can destroy edit recovery information                 
 in your profile. Assuming you are working under the same ISPF                  
 APPL on both SYSA and SYSB and are forced off of SYSA and logoff               
 normally from SYSB, you will not be presented with the edit                    
 recovery dialog when you logon again to either system.                         
                                                                                
 There is a similar caveat for edit recovery even when not sharing              
 the ISPF profile data set.  Because some recovery information is               
 stored in the ISPF profile, if you attempt to edit the same                    
 data set or same PDS member from a system that does not have                   
 recovery pending, you will be able to update the data set or                   
 PDS member without warning.  If you then attempt to edit that same             
 data set or PDS member from the system pending recovery and don't              
 cancel out of the recovery, you will lose the updates done from the            
 other system. However, if you are forced off a system and have edit            
 recovery pending, then re-logon to the same system, edit recovery              
 will work as expected.  I tend to run with recovery off and thus               
 avoid the issue altogether.                                                    
                                                                                
 2) If your system is not at OS/390 R10 or higher, you need ISPF                
 exit 16 to ensure unique names for the LOG,LIST and temporary data             
 set names. This also requires updating the ISPXDT exit definition              
 table in LMOD ISPEXITS and the ISPDFLTS module to let ISPF know you            
 are using exits. If you are at OS/390 2.8 or above, the ISPDFLTS               
 table is replaced by the new ISPF Configuration Utility - ISPCCONF.            
 You must specify ENABLE_ISPF_EXITS = YES in the configuration table            
 that is input to the utility. In the ISPCCONF dialog, this can be              
 found in the "ISPDFLTS, CUA Colors, and Other DM Settings" section.            
 My ISPF Exit 16 uses the convention of:                                        
    userid.SYSnnnn.SPFLOGn.LIST                                                 
    userid.SYSnnnn.SPFTEMPn.CNTL                                                
    userid.SYSnnnn.SPFn.LIST                                                    
 I link ISPEX16 right in with ISPXDT.                                           
                                                                                
 If you are at OS/390 R10 or higher, you can use an option in the               
 ISPF Configuration Utility as an alternative to using ISPF exit 16.            
 Specify ISPF_TEMPORARY_DATA_SET_QUALIFIER = SYSnnnn (or whatever               
 qualifier you desire). In the ISPCCONF dialog, this can be found as            
 "Additional Temporary Data Set Qualifier" in the "ISPF Site-wide               
 Defaults" section. The drawback to this method is that you will need           
 a different configuration table for each system unless you are at              
 the z/OS 1.5 level or above.  In z/OS 1.5 and above, a Static System           
 Symbol can be specified as part of the name and ISPF exit 16 is no             
 longer required: ISPF_TEMPORARY_DATA_SET_QUALIFIER = SYS&SYSNAME               
 For z/OS 1.9 and above, if you implement ISPF profile sharing via              
 PROFILE_SHARING=YES, you don't have to specify anything here and may           
 let it default to ISPF_TEMPORARY_DATA_SET_QUALIFIER = ISP&SEQ.                 
                                                                                
 3) As long as you are using GRS or MIM you don't need to worry                 
 about recovery data set names because an ISPF ENQ (SPFEDIT) will               
 be used to create unique names, otherwise there is another ISPF                
 exit for that (the data set name change exit).                                 
                                                                                
 I have provided the following samples to implement this:                       
    ISPDFLTS -  ASM/LNK ISPDFLTS via SMP/E usermod                              
    ISPEX16  -  ASM/LNK ISPF EXIT 16 and ISPXDT via SMP/E usermod               
    UMJES01  -  JES2 Source update via SMP/E usermod (OS/390 R10)               
    UMJES012 -  JES2 Source update via SMP/E usermod (z/OS R2 & >)              
    UMJES01O -  JES2 Source update via SMP/E usermod (OS/390 < R10)             
    UMJES06  -  JES3 Source update via SMP/E usermod                            
                (supplied by Edward E. Jaffe - Phoenix Software)                
                                                                                
 ** Please verify the source line numbers in the JES USERMODs to make           
 sure they match the line numbers of your JES version!!                         
                                                                                
 If you wish to use JES2 exit 44 instead of the JES2 source usermod             
 I am providing, there is a sample available on CBT file 346.                   
                                                                                
                    RMF ISPF Dialogs (optional)                                 
                                                                                
 If you use want to use the RMF ISPF dialogs from multiple systems              
 at the same time using the same TSO USERID, you will need to modify            
 the SYS1.SERBCLS(ERBRMF3X) CLIST for the ISPTABLE data set name.               
 For example, the CLIST as distributed:                                         
      SET TABLSUF = &STR(ISPTABLE)                                              
 can be changed to:                                                             
      SET TABLSUF = &STR(ISPTABLE).SYS&STR(&SYSSMFID)                           
                                                                                
                 Other ISPF applications (optional)                             
                                                                                
 Other ISPF applications (IBM, ISV, and local) may also have issues             
 with trying to use them concurrently from different systems using              
 the same TSO USERID.  For many ISPF applications, concurrent usage             
 with the same TSO USERID may not be possible. Each application                 
 needs to be examined on an individual basis.                                   
                                                                                
 Here are a few IBM product CLISTs that may be modified to support              
 concurrent usage with the same TSO USERID from different systems:              
                                                                                
          HCD  - Modify SYS1.SCBDCLST(CBDCHCD)                                  
          IPCS - Modify SYS1.SBLSCLI0(BLSCDDIR)                                 
          RMF  - Modify SYS1.SERBCLS(ERBRMF3X)    (see above)