Movng to a new hosting provider

Anybody have suggestions on how to quickly move from one datacenter to another?

I rent DNS services from my registrar so I have control over A/CNAME records.

I've got a dedicated machine at site A.

I have a new dedicated machine at site B.

I'm planning to transfer my applications from A to B in the near future.

Is it possible to minimize or eliminate or mitigate the impact of the DNS propagation delay?

The applications are database driven with user contributed content so it's not possible to mirror the sites because the Dbs would get out of sync.


-jay

 

Actually these days, the propogation is usually less than 5 minutes. Even setting up a brand new domain usually is done within about 4 hours or less

 

I moved 5 domains two months ago and it took almost three days for all the DNS updates to take effect ?

They were static sites so it wasn't that complicated.

 

Who is your registrar? It should not take that long. Currently our client use GoDaddy, Directi, and NetSol - and the transitions are less than 4 hours. A few times I have seen it less than 5 minutes.

This new host you are moving to - are you going to have a designated IP?

 

I can change the A record in seconds. It seems like some DNSs pick it up quickly but others don't.

For instance, I use Comcast Broadband for access from home and evidently they don't update their DNS cache very often. When I moved the sites two months ago it took almost 4 days for the domain name to resolve to the new IP addresses.

I have dedicated IPs on site A and Site B.

-jay

 

Not quite true. It all depends on the TTL value of your RR's. Some hosting companies set up default TTL to 1 day to minimize their DNS traffic. What I would do is to change this value to about an hour or less a few days before the switch to make sure all DNS caches are updated quickly when you switch.

J.D.

 

Some ISPs do a lot of DNS caching. I know SBC over on the East flushed all their records about 3-4 months ago and caused a lot of problems.

If they go by the RFC2308, they will have the TTL set to 1-3 hours hopefully since DNS does not put any strain on your servers really

 

This is the suggested (not even strongly suggested) time for caching negative responses. I don't think there's any rule for caching positive responses (correct me if I'm wrong). In practice, you will find TTL values all over the map (e.g. Verio sets up default TTL to one day; I have seen others set TTL to 4 hours or so or less).

J.D.

 

I don't think I can change any of the TTL values on my registrars DNS (only A/CNAME/MX) but what about doing this?:

1. Make my domain's name server the DNS running on the new server (that I have absolute control over) .
2, Change the TTL to ~3600 seconds.
2. Configure the new DNS with an A record that points to Site A (all requests will resolve to the old Site A server regardless of what DNS is used).
3. Let it run for a week or so to ensure that the information has propogated.
4. Move the software to Site B.
5. Change the A record to Site B.
6. Change the TTL back to 24 hours.

?

Below is the information from my current DNS via dnsreport.com

 

That is why I said suggested. If an ISP or hosting company has it set for 24 hours, well there is really no reason for that - except to hold you hostage for a few more hours. NetSol finally implemented their fast-DNS and all ISPs / hosting companies should update their TTL accordingly

 

When I move I make a mirror of the old hosting sever and move it to the new one. I disable any database services on the old site. While DNS propagates the old hosting site is showing all the content, but not interactive. When DNS propagates, the live site is waiting to service folks.

 

What kind of database are you using? With MSSQL, you can mirror the databases.

 

MySQL.

That's a little intimidating. How complicated is it?

 

OK, bad placement or use of the word.

Copy and shut down on old site, add live on new site. It's not as glamorous or great as it sounds. Basically the forums are inaccessable during the propagation.

None of my custom DB stuff is interactive, so it just works.

 

One of the better ways to smoothly move hosts I have found is after moving all files etc put up an index.asp/html/php redirect at your old host to the new ip

If your dedicated and have an ip this works, even on a shared host you will most likely get a temp url for propagation that you can use as a forwarder, ie yoursite.yournewhost.com type of thing. You can also put up forwarding pages for other directories and pages to stop your traffic gettings errors or old server pages.

That way during propagation, anyone still being sent to your old host will load the default index page which is a redirect to your new host.

You also have to do a forwarder at your old hosts email address to a new/separate email a/c, ie should be setup as a forwarder to a personal account so that if emails are sent to your old hosts server you can still get them.

Yes it can take a couple of hours, however many ISP's will still send your visitors to the old server for a period of time that can damage your site/business.