NAME

       Bio::DB::Failover - A Bio::DB::RandomAccessI compliant class which wraps a prioritized
       list of DBs

SYNOPSIS

           $failover = Bio::DB::Failover->new();

           $failover->add_database($db);

           # fail over Bio::DB::RandomAccessI.pm

           # this will check each database in priority, returning when
           # the first one succeeds

           $seq = $failover->get_Seq_by_id($id);

DESCRIPTION

       This module provides fail over access to a set of Bio::DB::RandomAccessI objects.

CONTACT

       Ewan Birney <birney@ebi.ac.uk> originally wrote this class.

   Support
       Please direct usage questions or support issues to the mailing list:

       bioperl-l@bioperl.org

       rather than to the module maintainer directly. Many experienced and reponsive experts will
       be able look at the problem and quickly address it. Please include a thorough description
       of the problem with code and data examples if at all possible.

   Reporting Bugs
       Report bugs to the Bioperl bug tracking system to help us keep track the bugs and their
       resolution. Bug reports can be submitted via the web:

         https://github.com/bioperl/bioperl-live/issues

APPENDIX

       The rest of the documentation details each of the object methods. Internal methods are
       usually preceded with a _

   add_database
        Title   : add_database
        Usage   : add_database(%db)
        Function: Adds a database to the Failover object
        Returns : Count of number of databases
        Args    : Array of db resources
        Throws  : Not a RandomAccessI exception

   get_Seq_by_id
        Title   : get_Seq_by_id
        Usage   : $seq = $db->get_Seq_by_id('ROA1_HUMAN')
        Function: Gets a Bio::Seq object by its name
        Returns : a Bio::Seq object
        Args    : the id (as a string) of a sequence
        Throws  : "no id" exception

   get_Seq_by_acc
        Title   : get_Seq_by_acc
        Usage   : $seq = $db->get_Seq_by_acc('X77802');
        Function: Gets a Bio::Seq object by accession number
        Returns : A Bio::Seq object
        Args    : accession number (as a string)
        Throws  : "no id" exception

   get_Seq_by_version
        Title   : get_Seq_by_version
        Usage   : $seq = $db->get_Seq_by_acc('X77802.2');
        Function: Gets a Bio::Seq object by versioned accession number
        Returns : A Bio::Seq object
        Args    : accession number (as a string)
        Throws  : "acc does not exist" exception