DBD::Gofer::Transport::stream(3)
NAME
DBD::Gofer::Transport::stream - DBD::Gofer transport for stdio
streaming
SYNOPSIS
DBI->connect('dbi:Gofer:transport=stream;url=ssh:username@host.example.com;dsn=dbi:...',...)
or, enable by setting the DBI_AUTOPROXY environment variable:
export DBI_AUTOPROXY='dbi:Gofer:transport=stream;url=ssh:username@host.example.com'
DESCRIPTION
Without the "url=" parameter it launches a subprocess as
perl -MDBI::Gofer::Transport::stream -e run_stdio_hex
and feeds requests into it and reads responses from it. But that's not
very useful.
With a "url=ssh:username@host.example.com" parameter it uses ssh to
launch the subprocess on a remote system. That's much more useful!
It gives you secure remote access to DBI databases on any system you
can login to. Using ssh also gives you optional compression and many
other features (see the ssh manual for how to configure that and many
other options via ~/.ssh/config file).
The actual command invoked is something like:
ssh -xq ssh:username@host.example.com bash -c $setup $run
where $run is the command shown above, and $command is
. .bash_profile 2>/dev/null || . .bash_login 2>/dev/null || . .profile 2>/dev/null; exec "$@"
which is trying (in a limited and fairly unportable way) to setup the
environment (PATH, PERL5LIB etc) as it would be if you had logged in to
that system.
The ""perl"" used in the command will default to the value of $^X when
not using ssh. On most systems that's the full path to the perl that's
currently executing.
PERSISTENCE
Currently gofer stream connections persist (remain connected) after all
database handles have been disconnected. This makes later connections
in the same process very fast.
Currently up to 5 different gofer stream connections (based on url) can
persist. If more than 5 are in the cache when a new connection is made
then the cache is cleared before adding the new connection. Simple but
effective.
TO DO
Document go_perl attribute
Automatically reconnect (within reason) if there's a transport error.
Decide on default for persistent connection - on or off? limits? ttl?
AUTHOR
Tim Bunce, <http://www.tim.bunce.name>
LICENCE AND COPYRIGHT
Copyright (c) 2007, Tim Bunce, Ireland. All rights reserved.
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself. See perlartistic.
SEE ALSO
DBD::Gofer::Transport::Base(3)
DBD::Gofer(3)
perl v5.10.0 2008-03-10 DBD::Gofer::Transport::stream(3)
Mac OS X 10.6 - Generated Thu Sep 17 20:11:20 CDT 2009