dump elasticsearch 2.x to mongodb and back to ES 6.x
问题 This question is more of theoretical than source code. I have a ES 2.x node which has more than 1.2TB data. We have 40+ indices with each having at-least 1 type. Here, ES 2.x is used as a database rather than as a search engine. The source which was used to dump data into ES 2.x is lost. Also, data is not normalised but a single ES document has multiple embedded documents. Our aim is to recreate the data source and at the same time to normalise it. What we are planning is: Retrieve data from