I heard that Google changed its datacenters recently from this post in WebProWorld that described a datacenter update. Of course, this led me to ask what exactly a datacenter was and what datacenters have to do with optimization.
I wrote to several search engine experts to get their explanations of the datacenters, and some discussion regarding their relevance to you.
What Is A Google Datacenter? Here is what a Google datacenter looks like: http://22.214.171.124/ (there are many of these), and here's a great definition from Daniel Brandt: "As I understand it, the data centers are different copies of the Google database located in various parts of the U.S. and Europe, and perhaps India.
"They are used for load balancing and perhaps now for geo-located SERPs. Other things being equal, you probably get connected to the data center closest to you."
Datacenters and Updates. Andy Beal describes the Google update and how it relates to the datacenters:
"Before Google updates its main index, www.google.com, it makes changes at its various datacenters first. This allows Google to test the new results across smaller user samples and tweak them before making an update available to everyone. This process usually happens over 2-4 days."
Why Watch The Datacenters? Since there are so many people who watch datacenters closely I asked why. Here's what Daniel said:
"They are watched closely because in the old days, which was a year ago, the Google data centers were more predictable. The "Google dance" would begin with new backlinks on www2.google.com and www3.google.com, and then propagate to the other data centers over the next few days. The new backlinks were an indication that the rankings had been recalculated for the entire index, which used to happen almost like clockwork, once a month."
"Once the new data appeared on www2 or www3, it would be stable. Therefore, if you watched these data centers, you had advance notice of the new index, and an indication of how your site would do over the next month until the next update."
So people watched the datacenters to have advance notice on how Google had changed their algorithm. Or, they used to. As Daniel said, "in the last few months, Google hasn't been predictable at all."
Dan Thies was not so impressed with the Datacenter analysts:
"When changes happen at one of the data centers, people with nothing better to do will post hundreds of messages at Webmaster World about it.
"Then they'll all switch the IP address in their hosts file to see if their PageRank went up or down. Then they'll all query the specific data center to see how they're doing on backlinks. Then they all panic and say it's the end of the world."
Jim Hedger found a bit more value in watching the datacenters, though perhaps not too much more than Dan: "I don't really spend much time checking the various datacenters as the SERPs are all the client really cares about. The only time they are really interesting is times like this when we are trying to figure out what the heck Google is up to. My trolling has produced no solid leads though."