Say the webserver is called foo, on the domain company.local. No ipv6 is enabled in the network. A network trace tells me that when the HTTP request comes in, the webserver sends out a DNS request for "AAAA foo.company.local". Nothing replies, and after 5 seconds it times out and carries on doing what it was doing.
Why would it be doing a DNS lookup for the IPv6 address of its own hostname? And more urgently, how can I stop it? -----Original Message----- From: Tom Lloyd Sent: 24 May 2012 16:26 To: 'Matijn Woudt' Cc: firstname.lastname@example.org Subject: RE: [PHP-DB] Mysterious 5 second delay on sybase_connect() I'm getting increasingly suspicious that DNS is to blame. If I was to do something like: $conn = sybase_connect( "10.0.0.11\SQLMAIN", $user, $pass ) Would that trigger a lookup of some variety? -----Original Message----- From: Matijn Woudt [mailto:tijn...@gmail.com] Sent: 24 May 2012 13:00 To: Tom Lloyd Cc: email@example.com Subject: Re: [PHP-DB] Mysterious 5 second delay on sybase_connect() On Thu, May 24, 2012 at 10:51 AM, Tom Lloyd <tomll...@wallcolmonoy.co.uk> wrote: > Hi there. I'm working on a PHP-driven project on Debian Squeeze that > connects to an instance of Microsoft SQL Server on Windows Server 2008. > I'm using the sybase extensions to PHP. > > Since I rebooted the webserver on the weekend, both the > sybase_connect() and sybase_pconnect() commands will sometimes take > exactly 5 seconds to execute. It seems to be random whether they do > this or not. I can't think of anything that could have been changed > by the reboot, unless a package was updated but its associated process never > got restarted... > > Does anyone know what might cause this behaviour? > > Cheers, > Tom Lloyd > It most likely has nothing to do with PHP, but is rather a routing issue. 5 seconds is the default connection time out for TCP/IP, so it probably makes sense that the connection is failing at a lower level. - Matijn