Too many Temporary failure received from server. Try again later

I have many “Temporary failure received from server. Try again later” error and in the

RAM used/quota = 29.7GiB / 32GiB

Metadata overhead warning. Over 75% of RAM allocated to bucket "xxxxx" on node "xxx.xxx.xxx.xxx" is taken up by keys and metadata. (repeated 1 times, last seen 10.004193 secs ago)

My question is, Why the couchbase server not worked correctly, We have 2GiB free ram and 90% free disk space, currently operation per seconds is less than 2

Whats wrong!

I have 86,322,239 items, the resident is 0.000185% , I don’t know why it’s very low
86,322,239 * 0.000144% ~ 12,430

How 12,430 items consumes 29.7GiB ram? each item must be 2.44MiB in average, and it’s not real, my items are tiny, less than a KiB

Help please
Why the system is not working well with 32G ram

Reply please, what’s wrong here