Hi,

I'm currently looking at using two accounts with two seperate providers and using one as the primary server with the other in backup.

To all intents and purposes I want the backup to take over if the primary fails but I'm not sure if
a) this is possible
...or
b) how to accomplish this if it is

The scenario I hope is possible is that if server 1 goes dead then DNS will look for the alternate option find it alive and direct a user to that instead.

Thanks in advance for any pointers to information and taking the time to reply..
:)
Martin

I always wondered about this...

Couldnt both hosts add the domain and you add 4 nameservers to that domain? Wouldnt it go down the list until it found one that worked?

Yes and no.

You can add 4 nameserves to your domain. One would be primary and the other 3 secondary.

We add 3 ns's to every domain we sell for extra redundancy. :-)

However, adding more A records doesn't mean it will search for one that works. Rather, it will setup a round robin effect, in which it simply gives the first, then the second to the next request, etc. Not all DNS servers support round robin, but most good ones do now.

Hmm.. ok so what in your opinion would be the best approach to providing a backup server as mentioned above?

Aloha
one other factor you have to look into is keeping data the same across both puters
if your content is static that should be no problem
but if it is dyanmic or stores data a whole new ballgame

Originally posted by Honu
Aloha
one other factor you have to look into is keeping data the same across both puters
if your content is static that should be no problem
but if it is dyanmic or stores data a whole new ballgame
Hi Honu,

That thought had actually occured to me and I've a rough idea that would involve the backup site checking for access to the primary server and posting the data to the DB there if possible. If not then saving to the local file system with a cron job to check for access later on and pushing the info across when the primary server was restored.

Would take some doing but should be possible.

Aloha
yeah there is another alternative telling a script to replicate every x amount of time
depends on how much data is added the other thing is is not to overwite info on one or the other
if one is purely back up might be better to cluster at the same colo place
yeah tough ideas for $$ I am trying to figure out the same thing

Originally posted by Honu
Aloha
yeah there is another alternative telling a script to replicate every x amount of time
depends on how much data is added the other thing is is not to overwite info on one or the other
if one is purely back up might be better to cluster at the same colo place
yeah tough ideas for $$ I am trying to figure out the same thing

I believe the best approach on dynamic data at least would be to have the following setup:

-Primary server stores data realtime
If it goes down
-Secondary server stores data to a simple flat file
-Secondary keeps checking for access to Primary (ie: if server is revived) every X mins/hours.
-If yes, then sends data to script on primary and includes.

-Secondary also provides full Backup of Primary data (not flat file but in full mySQL DB) so if Primary goes down for extended time I can always change variable on secondary to make it primary.
That way, system hardly stumbles.


BUT... this still doesn't solve the issue of getting users browsers going to redirect to the secondary site if the primary server is down. Can anyone give a definitive answer please?

Thanks in advance for ANY pointers
;)

C:\>nslookup google.com
Server: ns.direcpc.com

Non-authoritative answer:
Name: google.com
Addresses: 216.239.37.100, 216.239.33.100, 216.239.35.100


C:\>nslookup yahoo.com
Server: ns.direcpc.com

Non-authoritative answer:
Name: yahoo.com
Addresses: 216.115.108.243, 216.115.108.245


What's this? My instructor showed us this during a W2K Pro class.

Does this provide the failover that you are talking about?

If so, can these additional IPs just be added to our nameservers and expect it to work?

Originally posted by slade
C:\>nslookup google.com
Server: ns.direcpc.com

Non-authoritative answer:
Name: google.com
Addresses: 216.239.37.100, 216.239.33.100, 216.239.35.100


C:\>nslookup yahoo.com
Server: ns.direcpc.com

Non-authoritative answer:
Name: yahoo.com
Addresses: 216.115.108.243, 216.115.108.245


What's this? My instructor showed us this during a W2K Pro class.

Does this provide the failover that you are talking about?

If so, can these additional IPs just be added to our nameservers and expect it to work?

This is what my gut says is possible but like you I have no idea how... I'm thinking it's a DNS topic... Could I please have MOD dispensation to ask a rephrased question in the appropriate forum? :D :D :D

Ahah...

Ok on the surface it looks like we might have been right all along...


Domain Name: GOOGLE.COM
Registrar: NETWORK SOLUTIONS, INC.
Whois Server: whois.networksolutions.com
Referral URL: http://www.networksolutions.com
Name Server: NS2.GOOGLE.COM
Name Server: NS1.GOOGLE.COM
Name Server: NS3.GOOGLE.COM
Name Server: NS4.GOOGLE.COM
Updated Date: 13-jun-2001


Can anyone confirm that it's really this simple?