hi we have big E commerce site and it have around 3.5 million pages and around 3.4 million pages Index properly and time to time Google re-index from last month Google stop re-indexing the webpages Google Organic Ranking and traffic Suddenly Drop i don't know that what happening with site we have done all precaution on page or other SEO effect but we are unable to see good result. please check my website suggest that main problem and what action we have to take to improve organic ranking as well as re indexing. for analysis please check website http://is.gd/USxW8n