Using RUV for backout recovery

To perform a backout recovery for a file in batch, use the RECOVER BACKOUT command. Keywords on the command correspond to options you can control.

This topic contains the following information:

• • Performing a RUV backout recovery
  • Using the RECOVER BACKOUT command
  • Coding the RECOVER BACKOUT statements
  • Using the ARCHIVE_IN keyword
  • Using the BUFND keyword
  • Using the BUFNI keyword
  • Using the INVENTORY_ONLY keyword
  • Using the LSR_POOL keyword
  • Using the RECOVERY_MODE keyword
  • Using the SELECTION_EXIT keyword
  • Using the START_TIME keyword
  • Using the STOP_TIME keyword
  • Using the VSAM_FILE keyword

Performing a RUV backout recovery

To run a RUV backout recovery, perform the following steps:

1. Determine the VSAM file or files to include for backout recovery.
2. Build the JCL with the correct space allocation.
3. Build the RECOVER BACKOUT command to specify the files to recover and the options to use.
4. Run the recovery job or jobs.

Using the RECOVER BACKOUT command

To perform a backout recovery for one or more files in batch, use the RECOVER BACKOUT command. All keywords on the command correspond to options you can control.

Coding the RECOVER BACKOUT statements

To code a RECOVER BACKOUT statement, use the following syntax:

The following example shows a backout recovery of two files in a general ledger application. RUV can invoke a user exit routine during processing of the files.

Using the ARCHIVE_IN keyword

You can use the optional ARCHIVE_IN keyword on the RECOVER BACKOUT command to identify an archive data set to use as input to the recovery process.

It is recommended that you let RUV select the archive files for use. When you specify the archive files, you override the normal selection mechanism of RUV.

As the value of the ARCHIVE_IN keyword, specify the ddname of the DD statement that describes the archive data set in the JCL, or specify the fully qualified data set names of the archive data sets to have RUV allocate the data set dynamically.

Using the BUFND keyword

You can use the optional BUFND keyword on the RECOVER BACKOUT command to specify the number of data buffers to use. The default is 16, but you can change it to any desired value from 2 through 255. Values beyond 255 will be ignored. VSAM may override invalid combinations of BUFNI/BUFND.

Using the BUFNI keyword

You can use the optional BUFNI keyword on the RECOVER BACKOUT command to specify the number of data buffers to use. The default is 5, but you can change it to any desired value from 2 through 255. Values beyond 255 will be ignored. VSAM may override invalid combinations of BUFNI/BUFND.

Using the INVENTORY_ONLY keyword

You can use the optional INVENTORY_ONLY keyword on the RECOVER BACKOUT command to prevent RECOVER BACKOUT processing and show a listing of VSAM files that will be included in RECOVER BACKOUT, and the name of each RECOVER BACKOUT file if it was created by this job. The INVENTORY_ONLY keyword does not simulate the complete performance of the command, but reports on what it would have tried to do.

Set one of the following values for the INVENTORY_ONLY keyword. The default value is NO.

• YES
  Prevent RECOVER BACKOUT processing and issue a preliminary report on files that will be archived.
• NO
  Allow RECOVER BACKOUT processing.

Using the LSR_POOL keyword

You can use the optional LSR_POOL keyword on the RECOVER BACKOUT command to specify whether or not to use LSR POOLS (Local Shared Resource Pools designed to improve performance). The default is YES for KSDS and RRDS data sets. ESDS and IAM data sets do not use LSR POOLS, regardless of how the keyword is set.

Using the RECOVERY_MODE keyword

You can use the optional RECOVERY_MODE keyword on the RECOVER BACKOUT command to specify the Insertion Strategy for RUV to use when the RECOVER might cause inserts to the VSAM data set that create CI/CA splits. This keyword allows you to control the Insertion Strategy.

The default is NIS (Normal Insertion Strategy), which is good for most files. Files that have a large number of records inserted at one spot might benefit from the RECOVERY_MODE being set to SIS (Sequential Insertion Strategy). Before changing this parameter setting, see the Warning.

Using the SELECTION_EXIT keyword

You can use the SELECTION_EXIT keyword on the RECOVER BACKOUT command to have RUV invoke a user exit routine for each record that it processes during the recovery. It can also be used to override a user exit selection name defined during an ADD or UPDATE VSAM_FILE. See Using-the-SELECTION_EXIT-user-exit. As the value of the SELECTION_EXIT keyword, specify the program name of the exit routine.

Using the START_TIME keyword

Use the required START_TIME keyword on the RECOVER BACKOUT command to specify the start (earliest) timestamp of the range of journal records to include in the recovery process.

Time inputs for RECOVER will accept inputs that go to 5 characters past the decimal of seconds, as in yyyyjjjhhmmssthtth.

For more information, see Using-the-START_TIME-keyword.

Using the STOP_TIME keyword

You can use the optional STOP_TIME keyword on the RECOVER BACKOUT command to specify the stop (latest) timestamp of the range of journal records to include in the recovery process. The timestamp may be required for recovery to a specific point in time depending on the recovery situation.

Time inputs for RECOVER will accept inputs that go to 5 characters past the decimal of seconds, as in yyyyjjjhhmmssthtth.

For more information, see Using-the-STOP_TIME-keyword.

Using the VSAM_FILE keyword

Use the required VSAM_FILE keyword on the RECOVER BACKOUT command to specify the data set to be recovered. As the value of the keyword, specify the fully qualified data set name that identifies the file. You cannot specify masking characters in the value. You can code multiple VSAM_FILE keywords on the command.

If you use any of the optional keywords (such as START_TIME and STOP_TIME), you must code the optional keywords and their values after the DSN of the VSAM_FILE keyword but before the closing parenthesis.