[users@httpd] backup www server

[Matt Pearce <ma...@swiftdsl.com.au>]

Hi All,

Could someone tell me if their is a way to have a backup WWW server located
somewhere else and if your primary server falls over it will just access the
secondary one ??

I have been trying to work out how to do it (and googled also but I dont
think I was searching the right area) and I cant find any reference to what
I want.

Thanks for your help,

Matt.


---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
   "   from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org

RE: [users@httpd] backup www server

[Ben Yau <by...@cardcommerce.com>]

>
> I like the second idea a lot, so if I get what you mean correctly I have
> currently have this for my www server in my dns zone file:
>
> www.xxxxxxxx.com.au.           IN A    xxx.xxx.xxx.xxx
>
>
> I would simply add:
>
> www.xxxxxxxx.com.au          IN    A    yyy.yyy.yyy.yyy
>
> Thanks
>
> Matt.

I would recommend caution with  this.  It is a great idea for clustering.
First, realize that both machines wlil be serving pages so it isn't true
failover.  If you have the resources for both machines to serve, then that's
good.

However, if one server goes down, and you have to take it down, realize that
some requests will still attempt to go to the old IP because of the way DNS
works.

If you do this, two more things to keep in mind:
1) if one goes down, you need the other to still take over the IP of the old
one via a virtual IP or having a second NIC already installed and ready to
take over the IP.

OR

2) set the TTL in the DNS to be somehting very short so that DNS servers do
not cache the IP for very long (this wll put more load on your network and
DNs server)

Clustering (not using DNS) is a better solution.  I haven't used mod_backend
(which the prevoius poster suggested).  However, many firewalls do
clustering.  I used to work with Netscreen which did a great job of
clustering.   You could cluster multiple internal IP behind one extenral IP
so DNS always pointed user browsers to the one external IP.  Behind the
scenes at any time you could add/remove internal clients from the external
IP cluster.  I imagine most firewalls are able to do this kind of
combination of load-balancing/clustering/NAT


Ben


---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
   "   from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org

Re: [users@httpd] backup www server

[Matt Pearce <ma...@swiftdsl.com.au>]

I like the second idea a lot, so if I get what you mean correctly I have
currently have this for my www server in my dns zone file:

www.xxxxxxxx.com.au.           IN A    xxx.xxx.xxx.xxx


I would simply add:

www.xxxxxxxx.com.au          IN    A    yyy.yyy.yyy.yyy

Thanks

Matt.

Two solutions :

for apache 1.3.x : mod_backand (an old module to manage a grid of WWW
servers
=> cluster

Simply define 2 servers behind an alias in your DNS server


> Hi All,
>
> Could someone tell me if their is a way to have a backup WWW server
located
> somewhere else and if your primary server falls over it will just access
> the secondary one ??
>
> I have been trying to work out how to do it (and googled also but I dont
> think I was searching the right area) and I cant find any reference to
what
> I want.
>
> Thanks for your help,
>
> Matt.


---------------------------------------------------------------------
The official User-To-User support forum of the Apache HTTP Server Project.
See <URL:http://httpd.apache.org/userslist.html> for more info.
To unsubscribe, e-mail: users-unsubscribe@httpd.apache.org
   "   from the digest: users-digest-unsubscribe@httpd.apache.org
For additional commands, e-mail: users-help@httpd.apache.org