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dbd::gofer::transport::stream(3) [centos man page]

DBD::Gofer::Transport::stream(3)			User Contributed Perl Documentation			  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 DBD::Gofer perl v5.16.3 2013-04-04 DBD::Gofer::Transport::stream(3)

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DBD::Gofer::Transport::corostream(3)			User Contributed Perl Documentation		      DBD::Gofer::Transport::corostream(3)

NAME
DBD::Gofer::Transport::corostream - Async DBD::Gofer stream transport using Coro and AnyEvent SYNOPSIS
DBI_AUTOPROXY="dbi:Gofer:transport=corostream" perl some-perl-script-using-dbi.pl or $dsn = ...; # the DSN for the driver and database you want to use $dbh = DBI->connect("dbi:Gofer:transport=corostream;dsn=$dsn", ...); DESCRIPTION
The BIG WIN from using Coro is that it enables the use of existing DBI frameworks like DBIx::Class. KNOWN ISSUES AND LIMITATIONS
- Uses Coro::Select so alters CORE::select globally Parent class probably needs refactoring to enable a more encapsulated approach. - Doesn't prevent multiple concurrent requests Probably just needs a per-connection semaphore - Coro has many caveats. Caveat emptor. STATUS
THIS IS CURRENTLY JUST A PROOF-OF-CONCEPT IMPLEMENTATION FOR EXPERIMENTATION. Please note that I have no plans to develop this code further myself. I'd very much welcome contributions. Interested? Let me know! AUTHOR
Tim Bunce, <http://www.tim.bunce.name> LICENCE AND COPYRIGHT
Copyright (c) 2010, 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::stream DBD::Gofer APPENDIX
Example code: #!perl use strict; use warnings; use Time::HiRes qw(time); BEGIN { $ENV{PERL_ANYEVENT_STRICT} = 1; $ENV{PERL_ANYEVENT_VERBOSE} = 1; } use AnyEvent; BEGIN { $ENV{DBI_TRACE} = 0; $ENV{DBI_GOFER_TRACE} = 0; $ENV{DBD_GOFER_TRACE} = 0; }; use DBI; $ENV{DBI_AUTOPROXY} = 'dbi:Gofer:transport=corostream'; my $ticker = AnyEvent->timer( after => 0, interval => 0.1, cb => sub { warn sprintf "-tick- %.2f ", time } ); warn "connecting... "; my $dbh = DBI->connect("dbi:NullP:"); warn "...connected "; for (1..3) { warn "entering DBI... "; $dbh->do("sleep 0.3"); # pseudo-sql understood by the DBD::NullP driver warn "...returned "; } warn "done."; Example output: $ perl corogofer.pl connecting... -tick- 1293631437.14 -tick- 1293631437.14 ...connected entering DBI... -tick- 1293631437.25 -tick- 1293631437.35 -tick- 1293631437.45 -tick- 1293631437.55 ...returned entering DBI... -tick- 1293631437.66 -tick- 1293631437.76 -tick- 1293631437.86 ...returned entering DBI... -tick- 1293631437.96 -tick- 1293631438.06 -tick- 1293631438.16 ...returned done. at corogofer.pl line 39. You can see that the timer callback is firing while the code 'waits' inside the do() method for the response from the database. Normally that would block. perl v5.16.2 2010-12-29 DBD::Gofer::Transport::corostream(3)
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