Benjamin Smith lists@benjamindsmith.com wrote:
I've been exploring high-uptime availability solutions for our own, database-driven ASP. We have two sites, much as original poster describes, and 5-minute DNS, but many
larger
providers (EG: SBC, AOL) have DNS servers that seem to
ignore
TTL.
Apparently many others here serve content to users on networks other than those on AOL, SBC, etc... Or at least their comments seem to repeat that. ;->
It's gotta be either that, or it's the reality that they keep testing when their servers are using DNS that talk directly to (or are the) authority for the domain.
I suspect the latter. ;->
So, I've been at a quandary on this very same issue. We had a problem about 2 years ago where we had to switch to the failover in an emergency. From our end, we were "back up"
in
< 3 hours, (far less than the 6 hours allowed by contract)
but
it took over 48 hours for availability to approach 100%,
due to
the aforementioned DNS issues. (I hate you, SBC!)
Which is why you need 1-to-1 NAT for near-immediate uptime.
Of course, that doesn't help you if the provider of those IPs can't reach your 1-to-1 NAT equipment. That's why it's not a true failover.
An ideal, although bandwidth using, solution is to keep your router/1-to-1 NAT equipment at different locations. E.g., you have 4 sites -- 2 router/NAT, 2 servers. Only if and when you lost 3 sites would you go down.
But that gets mighty expensive. Which brings us to the next concept ...
So, do you know of a "getting started" for how to get an autonomous system number and run BGP? My skills as a
network
admin are a distant second to my primary skills...
In the US, start with the authority, ARIN -- http://www.arin.net/ They will give you the "do it yourself" cost.
I suspect you're below that, so you need to talk to your provider(s) about a solution. Unless you have just 1 provider (which means you're putting all your eggs in their backbone basket), it's pretty tough to do without ARIN at some point.
That's why it's typically better to rely on a partner who already has their own AS, and ties into 3+ providers. Again, this isn't something that you can do on your own, unless you have a lot of dough.
Again, this is where the small-to-medium ASP finds him/herself at the point where they either have to make a major investment to go bigger, partner to go bigger (although they will always be smaller than the partner), etc... It is *NEVER* something you can do in software, and that's the chronically dead wrong assumption.