Coincidentally, it is also a short name for the home assistant software in English.
39 karma · joined August 3, 2015
http://hostname:9200/_cat/indices
The 6th column gives you the number of records indexed. Send your request and refresh the browser.
Edit: According to the official ES documentation: "The bulk API makes it possible to perform many index/delete operations in a single API call. This can greatly increase the indexing speed."
They're fairly vague in their documentation about what's going on under the hood. I'm sure you could go dig through the source and find out more about whether it would really speed things up or not for a specific use case.