From: Daniel Berger <djberge@...>
Date: 2003-04-09T01:48:33+09:00
Subject: Re: Problem with timeout for DBI on Solaris

Brian Candler wrote:
> 
> On Wed, Apr 09, 2003 at 01:10:46AM +0900, Daniel Berger wrote:
> > As a test, we took down one of our test database machines and tried to
> > connect to it.  The problem is that, on Solaris boxes, it seems to
> > ignore the 'timeout' that we've wrapped the connection in.  Here's the
> > code:
> ...
> >       timeout(3){
> >          dbh = DBI.connect(dsn,user,passwd)
> >       }
> 
> I think that the problem is that once DBI.connect has committed to calling
> the Oracle C library, it won't come back until it has finished one way or
> the other. In other words, it doesn't play nicely with Ruby's cooperative
> threading. If a SIGALRM is raised after 3 seconds, Ruby just takes a note of
> it and lets the library call complete before taking action.
> 
> For Oracle, you can try using the ruby-oci8 library from RAA which supports
> non-blocking queries (although I don't know if it supports non-blocking
> connect). It comes with its own DBD which you have to install manually into
> /usr/local/lib/ruby/site_ruby/1.6/DBD/OCI8/OCI8.rb

I'll give it a shot.  FYI, I tried a similar script with Perl:

# Begin code
use strict;
use DBI;

my $dbh;

eval{
   alarm(5);
   $dbh = DBI->connect("dbi:Oracle:$db",$login,$passwd,{
      RaiseError => 1, PrintError => 1});
   alarm(0);
};

if($@){
   print "Error: $@\n";
   exit;
}
# End code

This was the result:

"Error: DBI->connect(db) failed: ORA-12560: TNS:protocol adapter error
(DBD ERROR: OCIServerAttach)"

So, it looks like it was a driver issue (?).  Perl's driver seems to be
non-blocking by default, which I think would be nice.

Thanks for the info.

Regards,

Dan