Failover

[Daniel_DBS]

Well I've been playing around with a simple failover technique tonight and it works quite well, so I thought I would share.

I am embarking on a new journey... Been wanting to do this for a while and I finally decided to. Myself and a good friend of mine are starting up our own hosting company.

Part of our plan involved redirecting users to our backup status blog whenever an issue like the one we all just went through occurs...

The easiest way I could think of to do this in a cost effective manner was to head over to ZoneEdit.com

I read around here on the forums and it seems not many people have tried this.

Once I signed up for a free account over at ZoneEdit and had all of my DNS information filled out, I payed a nominal fee of $10 per year for the failover service.

I then had it redirect my main sites traffic to the backup status blog whenever it determined the site was unreachable.

Now my backup status blog is actually in California at a different location and I have it setup as a subdomain with NS entries pointing to the server.

Once I had this all setup and done, I setup a 'copy' of my domain on the remote server so I could get backup MX going as well.

Now after all of that work, I gave it a shot by simply renaming the file it uses to sense if your site is down or not.

WHAMO!

After about 10 minutes, the backup blog fail over kicked in... I didn't have to clear my cache or anything! It just worked! So I decided to change it back, rename the file back to its real name and then within 10 minutes, my main site was back up.

Now I am not really sure how this will work with google since I am making it redirect to backup.domain.com instead of just to domain.com... But just to be on the safe side, I followed this guide to send any spiders a 503, but humans to the backup blog: http://www.askapache.com/htaccess/50...available.html

I really can't believe how well this system is working for less than a dollar per month for the fail over DNS and a basic shared account that one of my friends provided me for free

Now I know if I really wanted to get fancy I could just create a mirror of my main site and send users there instead of the backup blog, but we will save that for a later date

[Ron]

Good stuff!

If I recall correctly, now all you have to do is pay about 3 times that amount (or was it 5 times?) to get multiple DNS redundancy from zoneedit? Otherwise your site has a SPOF at zoneedit, no?

[Daniel_DBS]

Well I'm not is you are referring to multiple redundancy and single point of failure as them only checking if my site is online from one server and one uplink...

If so, no, I contacted ZoneEdit about that before I bought FO service and they check it from both of the name servers you are assigned. For instance, I was assigned NS3 and NS9, so every 10 minutes when they do the FO testing, they test from both NS3 and NS9... And then they also test using multiple uplinks, using the 70% rule... If 70% of the tried uplinks report it down, then they enable FO.

It is really quite nifty! If the entire NAP went out, then after a short period, my customers will then be routed to the backup server over in Cali and they can track the problem.

Also, another nifty tool... Blog by email

If the server is down, and everything gets routed to the backup blog, then I can use my smartphone, if i dont have internet, to email in a blog post to inform users of the downtime.

mwahaha... anywho, back to my devzone, errr i mean work