I'm using node js elasticsearch library to bulk insert items. I've read in the docs that the recommended bulk size to start from to test performance is 5MB-15MB. But what if I set a header Content-Encoding: gzip, deflate when making the insert? Does it mean in this case 5MB-15MB compressed, or is compression irrelevant here? Thanks.
The encoding that you are going to use will only compress the network traffic, in case compression happens. Elasticsearch will work on the original data only, irrespective of how you send data over network.