User Exit 12 (Multiple Data Set Log Processing)

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# User Exit 12 (Multiple Data Set Log Processing)

Note
UEX2 and UEX12 are mutually exclusive for an Adabas nucleus session: only one can be specified.

This user exit is given control by the Adabas nucleus during a switch from one multiple log data set to another for the purpose of copying the log data set before it is reused by Adabas. This switch occurs only if multiple data set data protection logging and/or multiple data set command logging is in effect for the session.

The user exit routine is designed to invoke a procedure that will execute the appropriate function (ALCOPY, CLCOPY or PLCOPY for Audit Log, Command Log or Protection Log) of the ADARES utility.

User exit 12 is invoked

- during Adabas nucleus startup if a multiple PLOG/CLOG/ALOG data set has to be copied;

- whenever a switch to another log data set occurs;

- at the end of a PLCOPY, CLCOPY or ALCOPY job if ADARES determines there are more copies needed;

- during Adabas nucleus shutdown.

The user exit is provided with information about the type of log (PLOG, CLOG or ALOG) and the status of the multiple log data sets.

The user exit can decide which action is to be taken:

- Ignore the call and allow Adabas to proceed;

- Submit a job to copy and mark as empty the log data set just filled (ADARES utility);

- Direct Adabas to wait for a specified interval, then call the user exit again with updated PLOG/CLOG/ALOG data set status information. During the wait interval, no commands that may produce log records for the log type being processed are allowed to proceed.

  Note
  If automated CLOG merge is being used in a cluster environment, it is critical that the exit 12 is used in the suggested manner to copy the CLOGs in a timely fashion as illustrated in the sample exit. Invoking the CLCOPY process in a different manner can result in time stamp inconsistencies between the CLOG datasets in a cluster environment causing CLOG merge issues. The PLOG merge is always automatic and also requires that the PLOGs are copied in a timely manner.

An example of user exit 12 is supplied with the Adabas installation procedure. Refer to the Adabas Installation documentation for more information.

The call to the user exit is made using a standard BASSM R14,R15 Assembler instruction. All registers must be saved when control is received and restored immediately prior to returning control to Adabas. Register 15 contains an action code as described in the user exit 2 section Output Parameter.

For more information regarding Standard MVS Calling Conventions and Return from User Exits please refer the respective sections in the Overview.

Note
User exit 12 must return the same AMODE value to the calling program that was active when user exit 12 was called. The recommended Assembler instruction to return is BSM 0,R14.

This document covers the following topics:

- User Exit 12 Calling Sequence

- User Exit Interface

- Output Parameter

- Activating the Sample User Exit

## User Exit 12 Calling Sequence

##### Multiple Log Processing Flow

## User Exit Interface

Optionally, the user exit may initialize its operation. It may store any value in field EX12USER of the EX12PARM parameter block to keep track of its resources. This field is considered as "owned" by the user exit and is supplied again for all subsequent executions of the exit. It is set to zero when the exit is first called and is not modified by Adabas thereafter.

The user exit is called again during termination to do any necessary finishing or 'cleanup' work.

### Parameters

##### User Exit 12 Parameters

### DSECT of the EX12PARM Parameter Block

             MACRO
             EX12PARM
    .**********************************************************************
    .*                                                                    *
    .* Name          Ex12Parm                                             *
    .*                                                                    *
    .* Component     ADABAS User Exit                                     *
    .*                                                                    *
    .* Function      Parameter list for User Exit 12                      *
    .*               (replacement for User Exit 2 for use when there are  *
    .*                two or more PLOGs, CLOGs or ALOGs)                  *
    .*                                                                    *
    .* Parameters    None                                                 *
    .*                                                                    *
    .* Restrictions  None                                                 *
    .*                                                                    *
    .* Notes         None                                                 *
    .*                                                                    *
    .**********************************************************************
    .*
    EX12PARM DSECT ,                   User Exit 12 Parameter List
    *
    EX12HDR  DS    0F                  Common header section
    *
    EX12USER DS    F                   Reserved for the user.  This field  +
                                       is initialized to zero before the   +
                                       exit is called the first time, and  +
                                       will not be altered by ADABAS after +
                                       that.  It can be used to maintain   +
                                       information across invocations.
    *
    EX12LOGT DS    X                   Log type
    EX12PLOG EQU     C'P'                PLOG
    EX12CLOG EQU     C'C'                CLOG
    EX12ALOG EQU     C'A'                ALOG
    *
    EX12TYPE DS    X                   Call type
    EX12TBEG EQU     C'S'                Nucleus start
    EX12TSW  EQU     C'W'                Log switch
    EX12TEND EQU     C'T'                Nucleus termination
    EX12TFRC EQU     C'F'                Forced switch
             DS    XL2                 Reserved
    *
    EX12NLOG DS    F                   Number of logs
    EX12DBID DS    F                   Database ID
    EX12NUCI DS    F                   Nucleus ID
    *
    EX12PLGN DS    F                   Current session PLOG number         +
                                         (zero for CLOGs)
    EX12NCMP DS    F                   Log just completed                  +
                                         (zero during initialization and   +
                                          for forced CLOG switch)
    EX12STAT DS    X                   Flags of next log in sequence
    EX12WNUC EQU     X'80'               Being written by the nucleus
    EX12FULL EQU     X'40'               Completed by the nucleus
    EX12RES  EQU     X'20'               Being copied by ADARES
    EX12CL5  EQU     X'08'               CLOGLAYOUT=5
    EX12NMRG EQU     X'04'               Records include time stamp (PLOG)
    *                                     CLOG not merged (cluster)
    EX12PMRG EQU     X'02'               Log partially merged (cluster)
    EX12UNUS EQU     X'00'               Unused and/or copied
             DS    XL3                 Reserved
             DS    4F                  Reserved
    *
    EX12HDRL EQU   *-EX12HDR           Length of header section
    *
    EX12ENT  DSECT ,
    EX12LOG  DS    0F                  Start of individual log dataset     +
                                       entries.  This section is repeated  +
                                       for the number of logs specified in +
                                       field EX12NLOG
    *
    EX12LTIM DS    XL8                 Time stamp of write to log dataset
    EX12LNUM DS    F                   Number of log dataset
    EX12LFLG DS    X                   Flags (mapped as in EX12STAT)
             DS    XL3                 Reserved
             DS    4F                  Reserved
    *
    EX12LOGL EQU   *-EX12LOG           Length of a log dataset entry
    *
    *
             MEND

## Output Parameter

Parameter | Usage
--- | ---
R15 = 0 | Nucleus continues processing.
R15 > 0 | R15 is treated as the number of seconds to wait before calling user exit 12 again with updated status for all log data sets. During this time, no commands that may create log entries are processed.

## Activating the Sample User Exit

The sample user exit is written in Assembler language. It performs the following functions:

- Issues a message identifying the reason and the type of log for which it was called.

- Issues a message with the status and timestamp of all log data sets that are not empty.

- If any log data set is full and at least one log data set has a status that is different from the last time the exit was called, the exit reads 80-byte records from an input file and writes them to an output file. It replaces all occurrences of the character "?" with either "P", "C" or "A", depending on whether the exit was invoked to process a PLOG, CLOG or ALOG event, respectively. This allows the input file to accommodate an event for either log type. Normally, the input file contains job control statements and the output file is directed to a job execution queue.

- If a record in the model job starts with the special stop mark “//*?” the exit will:

  - replace the stop mark with “//* ”,

  - stop copying further records to the output if it is PLOG or CLOG, or

  - continue copying records and replacing “?” with “A” if it is ALOG.

- If at least one log data set is not full, the exit returns to the caller with R15 zero, which allows Adabas to proceed.

- If all log data sets are full, the exit returns to the caller with R15 nonzero, which directs Adabas to wait for the number of seconds in R15, then call the exit again with an updated status of all log data sets. The default delay time is 30 seconds.

| Warning: Sample user exits and programs and are not supported under any maintenance contract agreement.

- Activating Sample User Exit 12

### Activating Sample User Exit 12

The sample user exit UX12SAMP is delivered on z/OS as source and as a load module that can be used without change or reassembly.

The source and load forms of the user exit are delivered in the Adabas source and load libraries, respectively. The job to assemble the user exit UX12ASML is located in the Adabas jobs library. The jobs library also contains a sample job UX12CJOB to be customized and submitted by the user exit that invokes the ADARES utility PLCOPY or CLCOPY function.

To activate the sample user exit 12:

1. Specify the `UEX12=UX12SAMP` ADARUN parameter for the Adabas nucleus and one or more of the following ADARUN parameters:

   - `NPLOG={2-8}`

     To use this parameter, you must also set `PLOGDEV` and `PLOGSIZE`.

     For more information about `NPLOG`, see Operations > ADARUN Parameter Directory > NPLOG Parameter: Number of Protection Log Data Sets.

   - `NCLOG={2-8}`

     To use this parameter, you must also set `CLOGDEV` and `CLOGSIZE`.

     For more information about `NCLOG`, see Operations > ADARUN Parameter Directory > NCLOG Parameter: Number of Command Log Data Sets.

   - `NALOG={2-8}`

     To use this parameter, you must also set `ALOGDEV` and `ALOGSIZE`.

     For more information about `NALOG`, see Operations > ADARUN Parameter Directory > NALOG Parameter: Number of Audit Log Data Sets.

2. Supply the job control model for the user exit to submit under the DDNAME COPYJOB.

3. If you want the sample user exit to submit jobs, provide the following DD statement:

       //INTRDR2  DD  SYSOUT=(*,INTRDR)

   Note
   Both sample user exits 2 and 12 use this DD statement for submitting PLCOPY, CLCOPY, or ALCOPY jobs.

### On this page

- User Exit 12 Calling Sequence
- User Exit Interface
- Output Parameter
- Activating the Sample User Exit