Setting high and low watermark, but not returned memory issue

Hello. This is Rui

Environment

Version: 4.5.1-2844 Community Edition (build-284)

Bucket count: 3

Number of nodes: 6

I changed mem_high_wat and mem_low_wat from 85%, 75% to 75%, 55%.

I also clicked on the bucket to see that it was applied on the monitoring page. (Check memory size)

The value of ep_exp_pager_time was also changed to 10 minutes (600).

However, memory is used in excess of the mem_high_wat value, but there is no operation at the expiry operation time.

I have a four question.

  1. Is there a water mark trigger?

  2. I’d like to know exactly how above works.

  3. Is there a manual or automated way to return the bucket memory?

  4. When couchbase returns memory, which monitoring metrics should I check?

Please reply.

Thank you.