Re: Mysterious 5 second delay on sybase_connect()
| From: | Charles Morris | Date: | Thu, 24 May 2012 16:40:15 +0000 |
| Subject: | Re: Mysterious 5 second delay on sybase_connect() | ||
| References: | 1 2 3 | Groups: | php.db |
| Request: | Send a blank email to php-db+get-48295@lists.php.net to get a copy of this message | ||
Is it's own host name in the hosts file and nsswitch.conf set up correctly?
Alternatively disable all the ipv6 adapters if you aren't using them.
On Thu, May 24, 2012 at 12:23 PM, Tom Lloyd <TomLloyd@wallcolmonoy.co.uk> wrote:
> 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: php-db@lists.php.net
> 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:tijnema@gmail.com]
> Sent: 24 May 2012 13:00
> To: Tom Lloyd
> Cc: php-db@lists.php.net
> Subject: Re: [PHP-DB] Mysterious 5 second delay on sybase_connect()
>
> On Thu, May 24, 2012 at 10:51 AM, Tom Lloyd <TomLloyd@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