Reindexing using NEST V5.4 - ElasticSearch

Question

I\'m quite new to ElasticSearch. I\'m trying to reindex a index in order to rename it. I\'m using NEST API v5.4. I saw this example:

var reindex =
    elast         


        

Answer 1

After search for 2 long days I found out the solution to reindex a index. In order to solve future problems, I'll provide my solution.

Nest Version - 5.4

var reindex = client.Reindex<object>(r => r
              .BackPressureFactor(10)
              // ScrollAll - Scroll all the documents of the index and store it for 1minute 
              .ScrollAll("1m", 2, s => s
                  .Search(ss => ss
                      .Index(oldIndexName)
                          .AllTypes())
                      // there needs to be some degree of parallelism for this to work
                      .MaxDegreeOfParallelism(4))
              .CreateIndex(c => c
                  // New index here
                  .Index(newIndexName)
                  .Settings(
                      // settings goes here)
                  .Mappings(
                      // mappings goes here))
              .BulkAll(b => b
                  // New index here!
                  .Index(newIndexName)
                  .Size(100)
                  .MaxDegreeOfParallelism(2)
                  .RefreshOnCompleted()));

the ReIndex method returns a cold IObservable on which you have to call .Subscribe() to kick off everything.

So, you need to add it to your code:

var o = new ReindexObserver(
            onError: (e) => { //do something },
            onCompleted: () => { //do something });
reindex.Subscribe(o);

Useful links to check this are:

Documentation

Issue 2660 on GitHub

Issue 2771 on GitHub