SQL Retry Logic

Automatic retry of unsuccessful backups

NetBackup for SQL Server provides the following options to retry unsuccessful

backup attempts.

NetBackup for SQL Server keeps track of the unsuccessful backups

that may have resulted from the execution of a batch file. When the

initial backup attempt is complete, the agent rewrites the batch file,

including only those operations that failed. The rewritten batch file

is launched automatically.

Automatic retry

Amanual retry is similar to an automatic retry except that NetBackup

does not launch the rewritten batch file. Instead it is written to the

install_path\dbext\mssql\retry\ directory. The user can then

choose when to run the new batch file.

Manual retry

To use automatic retry, add the following line to your batch file.

RESTARTTYPE AUTO

By default, the unsuccessful backups are retried one time automatically after 60

seconds. To change the delay following the unsuccessful attempt, then add the

following to your batch file.

RESTARTWAITSECONDS <integer>

You can also specify the number of retries. Add the following to your batch file.

NUMRESTARTS <1 to 9>.

To use manual retry, add the following line to your batch file.

RESTARTTYPE MANUAL

Retry may also be used with file checkpoints. You can create the batch file so that

any parts of the operation that fail are written to a new batch file that can be

launched either automatically or manually.

See “File checkpointing” on page 118.

You can easily enable file checkpointing with automatic retry in the backup dialog

in the NetBackup for SQL Server graphical user interface. Simply select a single

database (or filegroup), then from the "Resume options for this selection" list,

select Save work and restart at point of failure.

This action creates a batch file that contains the following scripting:

MAXRESTARTSETS 32

RESTARTWAITSECONDS 60

NUMRESTARTS 1

MAXRESTARTSETS 32 means that up to 32 pieces are backed up independently. The

keywords RESTARTWAITSECONDS and NUMRESTARTS are synonymous with the

following:

RETRYWAITSECONDS 60

NUMRETRIES 1

These keywords indicates the following things: first, that an automatic retry is

launched after 60 seconds for all of the pieces that failed to get backed up on the

first time. Second, the restart is attempted only one time. You can manually change

either of these parameters.

In addition, you can choose to not have the retry script automatically launched.

Replace the NUMRETRIES command with RETRYTYPE MANUAL.

NUMRETRIES 1

with

RETRYTYPE MANUAL.

When manual retry is enabled, the generated batch file for the components that

were unsuccessfully backed up is written to the following folder:

NB_INSTALL\dbext\mssql\temp folder

Note: All of the keyword-value pairs that are described in this topic are only

permitted in the first operation of the batch file.