Probably a lot, if you're like me. Have you ever watched someone stroll through the door, around the line, and walk up to the nearest cashier, occupied or not, and demand service now? Have you ever ended up just behind that person who just crashed the line? Have you ever been that person who just crashed the line?
Have you ever seen the line come to a screeching halt, while the manager tries to convince the line crasher to get back into the line, and wait politely to be served? Not fun for anyone, that scene. Nobody accomplishes much, while everybody calms down.
The load balancing server array "ghs.google.com" is similar to the line in the bank.
With your custom domain setup to use a CNAME referral to "ghs.google.com", each reader of your blog is uniformly and efficiently issued the IP address of the "next available BlogSpot server". There are thousands of BlogSpot servers, and the load (the readers of millions of Blogger blogs) is evenly spread across the entire array.
On the other hand, if your custom domain is forwarded to "xxxxxxxx.blogspot.com" (the BlogSpot address of your blog), each reader of your blog does a normal DNS lookup - and probably uses a cached IP address in getting a BlogSpot server.
If an IP address is in cache, it's likely that it's pointing to a server that's busy (how did the address get into cache after all?). Your readers will be competing with readers of other blogs, for server access. That's like the idiot who just crashed the line, nobody wins - everybody loses time and patience.
Similarly, blogs published to domain addresses which use an "A" referral to the alias array ("216.239.nn.21") will be a problem - for themselves and for others.
In an alternate scenario, the line crasher will walk up to an unoccupied cashier, who is just closing down and heading out to lunch. The line crasher stands in front of the cashier, who simply puts the "Out To Lunch" sign in place, and walks away, leaving the line crasher unattended, and with no place in line.
If the domain is forwarded (or if you have "A" or "CNAME" records to one or more fixed IP addresses) to server(s) that just went down, your reader gets a 404 - Server Not Found (not responding). This is a scenario being experienced by quite a few bloggers, starting 17 September 2007, and periodically by more bloggers.
Surely, the entire domain isn't down. No, most likely, the server.
A load balancing server (like a "next available cashier" line) assures that you always get a working server (not a cashier on the way to lunch).
I haven't changed anything!! It just stopped working on its own!!!
When you setup a CNAME referral to "ghs.google.com", Blogger provides an IP address of a server, at that moment in time, that's both
When you setup a fixed IP address (using either an "A" or "CNAME"), and your readers use the same IP address (or one of a few) every time, that server may be either
- Assigned by ghs.google.com to someone else, and busy.
For Blogger to work properly, everybody has to wait in line, and go to ghs.google.com, for a server assignment. There are thousands of servers at Google - at any time, any number might be offline. The load balancing host ghs.google.com dynamically assigns your reader a server that's available, if your blog DNS is properly setup to convince your reader's browser to ask for an available address.
If your blog bypasses load balancing, you cause two possible problems.
- If your designated server is down, your reader gets a 404 error, and no access to your blog.
- If your designated server is busy, your reader bypasses load balancing, and overloads it. The other users of that server get poor response, along with your readers.
Why treat your readers like line crashers? Let your readers play by the rules, just like everybody else. Use "CNAME" referral to "ghs.google.com" - let "ghs.google.com" assign the "next available server", and let everybody access your blog politely. If your DNS host doesn't support "CNAME" referrals (not all do, for some reason), find another DNS host that does.
You may, depending upon your need and current availability of Google servers, chose any one of three reliable DNS configurations.