Best approach for merging solr indexes of size 60GB and 10GB in minimum time?

Question

Lets say, I have a Solr Index of 60GB. I want to merge with it a 10GB Solr Index. What is the best way to merge them in minimum time. Can somebody give me a performance benchmark for how fast the merging process can be? I'm using JAVA to merge the index directories.

Thank you very much!

Answer 1

I would use Lucene's IndexMergeTool to merge these indexes. This class uses IndexWriter#addIndexes under the hood in case you need to embed this functionality in another tool. If you don't need your index to be optimized in the end, you could even use IndexWriter#addIndexesNoOptimize which may be faster.