Google updates their PageRank vector on a monthly basis. This process of updating is known as the Google Dance because pages dance up and down the rankings during the three days of updating computation.
Google stores dozens of copies of its search index across its clusters an during the Google dance, which is period of time between the start and end, of the index update, some servers will inevitably have an old version of the index.
So at any point during the “dance,” the same searches could yield very different results.
Normally, the Google dance takes a few days, and this period is considered to be the best time for web sites to update the content of their web pages.
While the dance has change and Google now uses several update processes, the same kind of problem can still occur at Google and the other search engines.
Many webmaster have come to fear the Google Dance. After working so hard to improve rankings (by hook or by crook or by good content), just a slight tweak by Google in their page rank or content score algorithms can ruin a webmaster’s traffic and business.
The Google dance is Google’s time of the month. The dance is a major re-ranking of web pages that occurs after the Deepbot has finished indexing content.
As soon as the dance finished, Google starts a new crawl in full swing, and of the new crawl does not harvest the updated web pages, webmasters will have to wait for another month before Google will have a fresh copy of their site.
It manifests itself in fluctuating site positions in search results and changes in an individual site’s toolbar rank.
It is a time of great excitement for site owners as their site gain or lose toolbar rank.
The Google dance is unannounced but can be detected when results between the various data centers that Google serves results from are out of synch.
However since the IPO Google has become much more protective of its operation and these data centers are no longer publicly visible except through their IP address.
Google Dance
