So many indices for activity_page_xxxxx in elasticsearch

Elastic Stack Elasticsearch
1

why there are so many indices of activity_page_xxxxx in Elasticsearch?
The default parameter of max_shards_per_node is 1000,
The activity_page_xxxxx is nearly 2000.

2

What is this index? I guess it's something you created? Are you using ILM? Datastreams?
What is your use case?

3

Activity_page is not created by ES?
So is there any way to find out it is created by whom, like user,IP any information can help.

4

I don't know.

What's the content of the index?

What other services did you start? What is your version?

5

ES version is 7.9
The ES cluster is an old cluster without maintenance for a long time,
no one knows the activity_page come from where, but it increase daily.

6

What is the content of the index?

GET /index/_search
7

Found some business information and asked other ones with this clue, now don't know data put from where.