NAME

DBIx::TryAgain - If at first you don't succeed, try DBIx::TryAgain.

SYNOPSIS

 my $dbh = DBIx::TryAgain->connect(...) or die $DBI::errstr;

OR

 my $dbh = DBI->connect(... dbi params.. { RootClass => "DBIx::TryAgain" } ) or die $DBI::errstr;

 $dbh->try_again_algorithm('fibonacci');
 $dbh->try_again_max_retries(5);
 $dbh->try_again_on_messages([ qr/database is locked/i ]);
 $dbh->try_again_on_prepare(1);

DESCRIPTION

This is a subclass of DBI which simply tries to execute a query again whenever the error string matches a given set of patterns.

By default the only pattern is qr[database is locked], which is what is returned by SQLite when the database is locked.

There is a delay between retries. Setting try_again_algorithm to 'constant', 'linear', 'fibonacci', or 'exponential' causes the corresponding algorithm to be used. The first five values for these algorithsm are :

    constant    : 1,1,1,1,1
    linear      : 1,2,3,4,5
    fibonacci   : 1,1,2,3,5
    exponential : 1,2,4,8,16

Modify the PrintError attribute and DBI_TRACE environment (as with DBI) to change the level of verbosity of this module.

In addition to retrying an execute(), DBIx::TryAgain and also retry a prepare statement, by calling $dbh->try_again_on_prepare(1);

AUTHOR

Brian Duggan, <bduggan at matatu.org>

SEE ALSO

DBI

TODO

Support error codes as well as messages.