Input a document triggers a task

Elastic Stack Elasticsearch
1

In ElasticSearch, is there a way that when a document is added it will trigger some other task?
For example, a document has contents “reader_count" is 3.
When that document is added to Elastic, Elastic (or triggers a task to) updates another document’s “total_reader_count” as += 3.

Wonder if this kind of thing is possible without querying.
Thanks in advance,

2

It's not directly, no.
You could do something with Watcher, or perhaps Percolator.

3

It seems I can use Percolator to do what is needed.
Thanks for the information.