MONITORING MESSAGES

  MONMSG         The monitor message (MONMSG) command monitors for the escape/status/notification

messages that exist in a program at run time and allows us to take the corrective action for those messages.

         The messages are sent to the program message queue for the conditions specified in the command. If condition exists, the CL command specified on the MONMSG command runs.

         It doesn’t handle diagnostic messages but we can receive those messages from the message queue to get additional information related to the error.

    Types of monitor message

  Escape Message

  Status or Notify Message         Escape Message

Escape message are send to tell your program of an error condition that forced the sender to end the program. By monitoring for escape message, you can take corrective actions or end your program.

         Status or Notify MessageStatus and notify message are send to tell your program of an abnormal condition that is not serious enough for sender to end. By monitoring for status or notify message, your program can detect this condition and not allow the function to continue.

    Two levels of MONMSG command

  Program level  Specific command level

          Program level

The MONMSG is specified immediately following the last declared command in the CL program.

It will catch all the error escape messages that exist in the program and doesn’t have satisfying command level MONMSG or doesn’t have any command level MONMSG.

         Specific command levelHere the MONMSG command immediately follows a CL command. If there is any error at a particular CL statement and it satisfies the condition specified in MONMSG, then the error is caught with this MONMSG.

e.g. Suppose there are multiple places in our program where we checking for the existence of an object. So rather than defining the MONMSG at many places, we will simply put it at program level.

FROM THE DESK OF N.K. ELURUPage 1

MONITORING MESSAGES

 

 Monitor message command syntax            MONMSG  MSGID ( )  CMPDTA ( ) EXEC ( )

   MSGID-Required   Ex: MSGID (MCH1211)  CMPDTA –(Optional)       Ex: MONMSG MSGID (MCH1211) CMPDTA (LIB)  EXEC - -(Optional)

 We can monitor for a specific message, e.g.    MONMSG    MSGID (CPF9821)  Or we can monitor for a list of messages, e.g.    MONMSG    MSGID (CPF9821 CPF9822 ……  CPF9830)  Now if we want to catch all the messages that start with CPF98.., then we can go for the below MONMSG:  MONMSG    MSGID (CPF9800) Now if we want to catch all the possible generic messages for CPF…., we can use the below MONMSG:  MONMSG    MSGID (CPF0000) To have more generic message monitor, we can go for:  MONMSG    MSGID (CPF0000 MCH0000) EXEC (GOTO ERROR)

 

FROM THE DESK OF N.K. ELURUPage 2

MONITORING MESSAGES

FROM THE DESK OF N.K. ELURUPage 3

MONITORING MESSAGES

   MONMSG / Difference between cpf0000 and cpf9999 in as400  

Before we go for the difference between CPF0000 and CPF9999, we need to understand how the

MONMSG works.

First, we can monitor for a specific message, e.g.

    MONMSG    MSGID (CPF9821)

 

Or we can monitor for a list of messages, e.g.

    MONMSG    MSGID (CPF9821 CPF9822 ……  CPF9830)

 

Now if we want to catch all the messages that start with CPF98.., then we can go for the below

MONMSG:

  MONMSG    MSGID (CPF9800)

 

Now if we want to catch all the possible generic messages for CPF…., we can use the below

MONMSG:

  MONMSG    MSGID (CPF0000)

 

To have more generic message monitor, we can go for:

  MONMSG    MSGID (CPF0000 MCH0000) EXEC (GOTO ERROR)

 

But now suppose we have given the generic message handling MONMSG command as above, but

the program generates a message that is not in this generic list of messages then that will not be

handled.

That unhandled message is converted into CPF9999 by our system automatically.

FROM THE DESK OF N.K. ELURUPage 4

MONITORING MESSAGES

Hence, all the unhandled messages are converted to CPF9999, which actually is being handled by

our generic MOMSG command.

 

Example

Suppose there is any program which needs parameter value (file name) to be passed, but actually we

are not passing the value in this case. In the program when we try to delete the file then what we

get  an error CPD0071.

Hence, here this unhandled exception is converted to CPF9999 and then it is handled via

CPF0000(GENERIC MSG HANDLER).

FROM THE DESK OF N.K. ELURUPage 5