ANNOUNCE: DBIx::HA 0.55, High Availability for DBI

DBIx::HA is a pure-perl high availability module for DBI. It 
specializes in failover and integrates properly with mod_perl and 
Apache::DBI, and should be integrated in your programs if you are using 
Oracle listeners or Sybase OpenSwitch (or any other database-level high 
availability layer).
Compared to DBD::Multiplex, DBIx::HA does not do multiple simultaneous 
writes. However, it can probably be used in conjunction with 
DBD::Multiplex to provide a best of both worlds.
Subsequent releases will use Sys::SigAction for signal handling.

$CPAN/modules/by-authors/id/H/HA/HASSEILY/DBIx-HA-0.55.tar.gz

   'DBIx-HA-0.55.tar.gz' => {
     'mtime' => '2004-01-30',
     'md5-ungz' => '8406276a98781073ae592009fc2bb48e',
     'md5' => '915ed803e0a7d40bafbcb783766769c5',
     'size' => 9335
   }


 From the README:

DBIx::HA is a High Availability module for DBI. It is implemented by
overloading the DBI connect, prepare and execute methods and can
be seamlessly used without code modification except for initialization.

DBIx::HA also works seamlessly with Apache::DBI when available, and
ensures that cached database handles in the Apache::DBI module are 
properly
released when failing over.

Features of DBIx::HA are:

- multiple failovers
Should a datasource become unavailable, queries are automatically sent 
to
the next available datasource in a user-configured datasource stack.
All subsequent queries continue to hit the failover server until
reinitialized. This ensures that a failed datasource can be properly 
brought
back online before it is put back in service.

- timeouts
Database calls are wrapped in user-configurable timeouts. Connect and 
execute
timeouts are handled independently.

- configurable retries
Queries can be retried n times before a datasource is considered failed.

- callback function
A user-defined callback function can be called upon abnormal failure and
disconnection from a datasource in order to clean locally cached 
handles and
perform other housekeeping tasks.

- inter-process automatic failover under mod_perl
Failover can be triggered for a single process or a set of processes at 
the
application level. Specifically designed for Apache's multi-process 
model,
if one mod_perl process triggers a failover, it is propagated to all 
other
mod_perl processes using the same database handle.


DBIx::HA was designed primarily for reliability and speed. Functionality
that would compromise speed was not considered. This module has been 
tested
extensively at very high loads in the Apache/mod_perl/Sybase 
environment.

---
Henri Asseily