@tingking23 I wonder if this is due to some difference in how we index things. I wonder if you could go back to your 1.x version and create a new index with all the mappings but don't index documents into it. Then upgrade this to 2.x and run your indexing test? I really wanna know if we changed something in mappings that make these things go nuts? we do a lot of different things based on the version the index was created on.