HPRPSMSG start option


   .-HPRPSMSG--=--ALL----------.   
>>-+---------------------------+-------------------------------><
   '-HPRPSMSG--=--ps_msg_count-'

Specifies whether VTAM® should enable the path switch message reduction and summarization function. This function limits the number of HPR path switch started message groups that can be issued during a path switch event interval (60 seconds). The corresponding path switch completed or failed message group for a given RTP pipe is issued only if the path switch started message group could be issued for that RTP pipe. A path switch event time interval is initiated when any path switch event (started, failed, or completed) occurs, and a path switch event time interval has not already been started.

At the end of the time interval, a summary of the path switch events is issued to the console. The path switch message summary is always issued to the console at the end of the time interval, whether or not messages were suppressed. The summary includes all path switch events that occurred during the specified path switch event time interval, including path switch event information that was issued to the console. If the ps_msg_count value uses the default value ALL or is coded as ALL, the path switch message reduction and summarization function is disabled. When the value ALL is coded or used as the default, all path switch message groups can be issued. If the current value of the HPRPSMSG operand is not appropriate for your system, you can modify the HPRPSMSG value using the MODIFY VTAMOPTS command.

Rule: HPRPSMSG is meaningful only if VTAM provides RTP-level HPR support. At a minimum, the NODETYPE start option must also be coded and the RTP parameter must be specified on the HPR start option.

Results:

When you modify the value of the HPRPSMSG start option, the new value goes into effect immediately. If path switches are actively occurring while this start option is dynamically changing, the display output presented to you might not be consistent.
The path switch message summary is not issued to the console when VTAM is halting.

This start option does not directly control the IST1494I (Completed) or IST1494I (Failed) message groups. If the IST1494I (Started) message group was issued for a specific RTP pipe, then the IST1494I (Completed) or IST1494I (Failed) message group is issued. If the IST1494I (Started) message group was not issued for a specific RTP pipe, then the IST1494I (Completed) or IST1494I (Failed) message group is not issued.

The path switch message reduction function is useful in large installations that have hundreds or thousands of RTP endpoints on z/OS® Communications Server. In the event of a large network outage, this function can prevent VTAM from flooding the system console log with redundant path switch messages. Although this function reduces the amount of path switch information that is issued to the console log, the summary information attempts to supply the operator with enough information to understand the size and scope of the outage.

Tip: The HPR path switch message reduction function might inhibit some path switch completion messages from being issued. The IST1494I message group supplies the APPN route that the RTP pipe is using after the path switch completes. Another way to obtain the APPN route for a specific RTP pipe is to issue the D NET,ID=rtppuname command. For more information about this command, see z/OS Communications Server: SNA Operation.

Restriction: The HPR path switch message reduction function is not associated with the message flooding prevention table. For predictable results, do not code the IST1494I message in the message-flooding prevention table when the HPR path switch message reduction function is enabled. For more information about message-flooding prevention and the IBM-supplied message-flooding prevention table, see z/OS Communications Server: SNA Resource Definition Reference.

Rule: The HPR path switch message reduction and summarization function does not affect HPR path switch messages that are initiated by the MODIFY RTP command. When you issue the MODIFY RTP command, you will see all related path switch messages.

The HPR path switch summary messages provide information for up to fifty partner CPs in ten network IDs.

Path switch messages:

When an RTP pipe enters the path switch state, the following message group is issued to the console log:

IST1494I PATH SWITCH STARTED FOR RTP puname  TO cpname
[IST1817I PATH SWITCH REASON: RTP CONNECTION UNAVAILABLE]
[IST1818I PATH SWITCH REASON: SHORT REQUEST RETRY LIMIT EXHAUSTED]
[IST1819I PATH SWITCH REASON: TG INOP]
[IST1820I PATH SWITCH REASON: MODIFY RTP COMMAND ISSUED]
[IST1821I PATH SWITCH REASON: AUTO PATH SWITCH FOR PSRETRY]
[IST1822I PATH SWITCH REASON: UNKNOWN]
[IST1937I PATH SWITCH REASON: INITIATED BY REMOTE PARTNER]
[IST2239I PATH SWITCH REASON: MNPS ENDPOINT RECOVERY]
[IST2335I PATH SWITCH REASON: XMIT STALL DETECTED]
IST314I END

When an RTP pipe successfully completes the path switch process, the following message group is issued to the console log:

ST1494I PATH SWITCH COMPLETED FOR  RTP puname  TO cpname
IST1480I RTP END TO END ROUTE - RSCV PATH
IST1460I  TGN    CPNAME            TG TYPE      HPR
IST1461I  tgn    cpname            tgtype       hpr
   .
   .
   .
IST314I END

When an RTP pipe fails to successfully complete a path switch, the following message group is issued to the console:

IST1494I PATH SWITCH FAILED FOR RTP puname  TO cpname
IST1495I NO ALTERNATE ROUTE AVAILABLE
IST314I END

Path switch message summary examples:

At the end of an HPR path switch event time interval, an IST2191I message group is issued to the system console. For complete information about the IST2191I message group, see z/OS Communications Server: SNA Messages.

The HPR path switch summary messages provide information for up to fifty partner CPs in ten NETIDs.

The path switch message event time interval is set when the first pipe enters the path switch state. In some cases, when RTP path switches complete quickly, the path switch summary message group might contain information related to the path switch started events and the path switch completion events. This situation might occur when HPRPSMSG=10 is specified and 20 RTP pipes enter and successfully complete the path switch within 60 seconds. Message group IST1494I (Started) is issued to the console for the first ten RTP pipes. Message group IST1494I (Started) is not issued to the console for the next ten RTP pipes. When all the RTP pipes successfully complete the path switch process, the message group IST1494I (Completed) is issued for the first ten RTP pipes [the RTP pipes for which the message group IST1494I (Started) was previously issued}. Because all of these path switch events occur within the same 60-second interval, a total of ten IST1494I (Started) and ten IST1494I (Completed) message groups are issued to the console. When the 60-second time interval ends, the IST2191I path switch summary message group, similar to the following example, is issued to the console log.

IST2191I HPR PATH SWITCH SUMMARY FROM 03/21/06 AT 09:45:14     
IST924I -------------------------------------------------------------   
IST2192I STARTED   =    20                                              
IST2193I   TGINOP  =    20    SRQTIMER =     0    PSRETRY     =     0   
IST2194I   PARTNER =     0    MNPS     =     0    UNAVAILABLE =     0   
IST2195I   NETWORK =     5  HIGH =     5  MEDIUM =     5  LOW =     5   
IST924I -------------------------------------------------------------   
IST2196I COMPLETED =    20                                              
IST2195I   NETWORK =     5  HIGH =     5  MEDIUM =     5  LOW =     5   
IST924I -------------------------------------------------------------   
IST2197I FAILED    =     0                                              
IST2195I   NETWORK =     0  HIGH =     0  MEDIUM =     0  LOW =     0   
IST924I -------------------------------------------------------------   
IST2198I NETID          STARTED          COMPLETED         FAILED        
IST2199I   CPNAME   NET  HI MED LOW  NET  HI MED LOW  NET  HI MED LOW 
IST2205I ---------  ---------------  ---------------  ---------------   
IST2200I NETA         5   5   5   5    5   5   5   5    0   0   0   0
IST2201I   SSCP7A     1   1   1   1    1   1   1   1    0   0   0   0
IST2201I   SSCP3A     1   1   1   1    1   1   1   1    0   0   0   0
IST2201I   SSCP7B     1   1   1   1    1   1   1   1    0   0   0   0
IST2201I   SSCP2AB    1   1   1   1    1   1   1   1    0   0   0   0
IST2201I   SSCP99     1   1   1   1    1   1   1   1    0   0   0   0
IST924I -------------------------------------------------------------   
IST2206I 40 PATH SWITCH EVENTS FOR 5 CPS IN 1 NETIDS 
IST314I END

When path switches do not complete quickly, the path switch information associated with a given RTP pipe might be spread across multiple path switch summary message groups. This situation might occur when HPRPSMSG=10 and HPRPST=(4M,4M,2M,2M) are specified, and 20 RTP pipes (five low priority, five medium priority, five high priority, five network priority) enter the path switch state. Message group IST1494I (Started) is issued to the console for the first ten RTP pipes. Message group IST1494I (Started) is not issued to the console for the next ten RTP pipes. In this example, an alternate route is not available. All the RTP pipes remain in the path switch state until their respective HPRPST timers expire. When all the timers have expired, the path switches fail. Because the HPRPST values for the various priorities are specified as different values, the path switches fail at different times. When the current path switch message event interval ends, a summary of twenty path switch started events, which are similar to the following example, is issued to the console.

IST2191I HPR PATH SWITCH SUMMARY FROM 04/27/06 AT 06:22:11     
IST924I -------------------------------------------------------------   
IST2192I STARTED   =    20                                              
IST2193I   TGINOP  =    20    SRQTIMER =     0    PSRETRY     =     0   
IST2194I   PARTNER =     0    MNPS     =     0    UNAVAILABLE =     0   
IST2195I   NETWORK =     5  HIGH =     5  MEDIUM =     5  LOW =     5   
IST924I -------------------------------------------------------------   
IST2196I COMPLETED =     0                                              
IST2195I   NETWORK =     0  HIGH =     0  MEDIUM =     0  LOW =     0   
IST924I -------------------------------------------------------------   
IST2197I FAILED    =     0                                              
IST2195I   NETWORK =     0  HIGH =     0  MEDIUM =     0  LOW =     0   
IST924I -------------------------------------------------------------   
IST2198I NETID          STARTED          COMPLETED         FAILED        
IST2199I   CPNAME   NET  HI MED LOW  NET  HI MED LOW  NET  HI MED LOW 
IST2205I ---------  ---------------  ---------------  ---------------   
IST2200I NETA         5   5   5   5    0   0   0   0    0   0   0   0
IST2201I   SSCP3A     1   1   1   1    0   0   0   0    0   0   0   0
IST2201I   SSCP7A     1   1   1   1    0   0   0   0    0   0   0   0
IST2201I   SSCP99     1   1   1   1    0   0   0   0    0   0   0   0
IST2201I   SSCP7B     1   1   1   1    0   0   0   0    0   0   0   0
IST2201I   SSCP2AB    1   1   1   1    0   0   0   0    0   0   0   0
IST924I -------------------------------------------------------------   
IST2206I 20 PATH SWITCH EVENTS FOR 5 CPS IN 1 NETIDS 
IST314I END

In this example, after 2 minutes elapsed, the five network and five high priority RTP pipes failed. After the attempts failed, a new 60-second path switch interval began. The message group IST1494I (Failed) was issued only for the RTP pipes for which the message group IST1494I (Started) was issued previously. When the 60-second interval expired, the path switch summary message group IST2191I was issued:

IST2191I HPR PATH SWITCH SUMMARY FROM 04/27/06 AT 06:23:11     
IST924I -------------------------------------------------------------   
IST2192I STARTED   =     0                                              
IST2193I   TGINOP  =     0    SRQTIMER =     0    PSRETRY     =     0   
IST2194I   PARTNER =     0    MNPS     =     0    UNAVAILABLE =     0   
IST2195I   NETWORK =     0  HIGH =     0  MEDIUM =     0  LOW =     0   
IST924I -------------------------------------------------------------   
IST2196I COMPLETED =     0                                              
IST2195I   NETWORK =     0  HIGH =     0  MEDIUM =     0  LOW =     0   
IST924I -------------------------------------------------------------   
IST2197I FAILED    =    10                                              
IST2195I   NETWORK =     5  HIGH =     5  MEDIUM =     0  LOW =     0   
IST924I -------------------------------------------------------------   
IST2198I NETID          STARTED          COMPLETED         FAILED        
IST2199I   CPNAME   NET  HI MED LOW  NET  HI MED LOW  NET  HI MED LOW 
IST2205I ---------  ---------------  ---------------  ---------------   
IST2200I NETA         0   0   0   0    0   0   0   0    5   5   0   0
IST2201I   SSCP3A     0   0   0   0    0   0   0   0    1   1   0   0
IST2201I   SSCP7A     0   0   0   0    0   0   0   0    1   1   0   0
IST2201I   SSCP99     0   0   0   0    0   0   0   0    1   1   0   0
IST2201I   SSCP7B     0   0   0   0    0   0   0   0    1   1   0   0
IST2201I   SSCP2AB    0   0   0   0    0   0   0   0    1   1   0   0
IST924I -------------------------------------------------------------   
IST2206I 10 PATH SWITCH EVENTS FOR 5 CPS IN 1 NETIDS 
IST314I END

After 4 minutes elapsed, the final ten RTP pipe path switch attempts failed. The following information shows a summary display:

IST2191I HPR PATH SWITCH SUMMARY FROM 04/27/06 AT 06:25:11     
IST924I -------------------------------------------------------------   
IST2192I STARTED   =     0                                              
IST2193I   TGINOP  =     0    SRQTIMER =     0    PSRETRY     =     0   
IST2194I   PARTNER =     0    MNPS     =     0    UNAVAILABLE =     0   
IST2195I   NETWORK =     0  HIGH =     0  MEDIUM =     0  LOW =     0   
IST924I -------------------------------------------------------------   
IST2196I COMPLETED =     0                                              
IST2195I   NETWORK =     0  HIGH =     0  MEDIUM =     0  LOW =     0   
IST924I -------------------------------------------------------------   
IST2197I FAILED    =    10                                              
IST2195I   NETWORK =     0  HIGH =     0  MEDIUM =     5  LOW =     5   
IST924I -------------------------------------------------------------   
IST2198I NETID          STARTED          COMPLETED         FAILED        
IST2199I   CPNAME   NET  HI MED LOW  NET  HI MED LOW  NET  HI MED LOW 
IST2205I ---------  ---------------  ---------------  ---------------   
IST2200I NETA         0   0   0   0    0   0   0   0    0   0   5   5
IST2201I   SSCP3A     0   0   0   0    0   0   0   0    0   0   1   1
IST2201I   SSCP7A     0   0   0   0    0   0   0   0    0   0   1   1
IST2201I   SSCP99     0   0   0   0    0   0   0   0    0   0   1   1
IST2201I   SSCP7B     0   0   0   0    0   0   0   0    0   0   1   1
IST2201I   SSCP2AB    0   0   0   0    0   0   0   0    0   0   1   1
IST924I -------------------------------------------------------------   
IST2206I 10 PATH SWITCH EVENTS FOR 5 CPS IN 1 NETIDS 
IST314I END