[Pdns-users] fail over for web server

[Darren Gamble]

Good day,

You will not be able to implement this with just pdns.  There is no way for the DNS server to know which servers are online or offline on its own.  The "failover" you read about is likely that for the DNS server itself.

As Kenneth noted, if you have any tools that can identify the status of the services, they can issue the appropriate commands to your DNS server.  Note that this would require a very low TTL value on the RR to be effective.

Note that the most common business solution to this problem is to use load-balancing technology- either a hardware server pair in front of the servers, or software on both web servers to manage a VIP.  But, this is just the most common solution, not the only one.

FYI,

============================
Darren Gamble
Systems Architect, Regional Services
Shaw Cablesystems GP
630 - 3rd Avenue SW
Calgary, Alberta, Canada
T2P 4L4
(403) 781-4948
 

> -----Original Message-----
> From: pdns-users-bounces at mailman.powerdns.com [mailto:pdns-users-
> bounces at mailman.powerdns.com] On Behalf Of Jean Chiappini
> Sent: Wednesday, August 15, 2007 7:55 AM
> To: ktm at rice.edu
> Cc: pdns-users at mailman.powerdns.com
> Subject: Re: [Pdns-users] fail over for web server
> 
> Thank you for your response. Yes it is one possiblity, we use zabbix,
> but I prefered a mechanism based on pdns directly...
> 
> Regards
> 
> Jean
> 
> >>> Kenneth Marshall <ktm at rice.edu> 08/15/07 3:24 PM >>>
> Jean,
> 
> One typical way to implement this is to use Nagios to monitor
> your web servers. Then if one goes offline, issue the appropriate
> update to the PDNS database.
> 
> Ken
> 
> On Wed, Aug 15, 2007 at 01:43:28PM +0200, Jean Chiappini wrote:
> > Hello,
> >
> > I setup a pdns with approximately 90 domains. For all domains we have
> > two web servers. Now, if a web server is down, 50% of the request
> failed
> > because the web server is not available due to down time.
> >
> > I read in the documentation that it is possible to make fail over with
> > pdns, but I don't fin how make this...
> > Someone has tested the failover with pdsn ? In case of yes, could you
> > explain me how I need to setup my pdns please ?
> >
> > Regards
> >
> > Jean
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