etcd: etcd 3.5 db_size problem

What happened?

I have 3-node etcd cluster version 3.5.2. I noticed a sitituation that endpoint’s db_size is constantly growing. I have to perform compaction and defrag manually so that the db_size value cannot reach to limitation. I have not faced any similar problem in 3.2 version.

±-------------------±-----------------±--------±--------±----------±-----------±----------±-----------±-------------------±-------+ | ENDPOINT | ID | VERSION | DB SIZE | IS LEADER | IS LEARNER | RAFT TERM | RAFT INDEX | RAFT APPLIED INDEX | ERRORS | ±-------------------±-----------------±--------±--------±----------±-----------±----------±-----------±-------------------±-------+ | 10.201.64.106:2379 | 6af28eee6b8fd63a | 3.5.2 | 18 MB | true | false | 3 | 7509221 | 7509221 | | | 10.201.64.107:2379 | 8t2ae31d2c14413e | 3.5.2 | 18 MB | false | false | 3 | 7509221 | 7509221 | | | 10.222.82.121:2379 | c6131f42ed372576 | 3.5.2 | 18 MB | false | false | 3 | 7509221 | 7509221 | | ±-------------------±-----------------±--------±--------±----------±-----------±----------±-----------±-------------------±-------+

What did you expect to happen?

I expect the db size to not increase that fast. Or I shouldn’t do the defrag process manually.

How can we reproduce it (as minimally and precisely as possible)?

Anything else we need to know?

No response

Etcd version (please run commands below)

$ etcd --version
# paste output here

$ etcdctl version
etcdctl version: 3.5.2
API version: 3.5

</details>


### Etcd configuration (command line flags or environment variables)

<details>

# paste your configuration here
 --name milano01 \
 --data-dir /var/lib/etcd \
 --initial-advertise-peer-urls http://10.201.64.106:2380 \
 --listen-peer-urls http://10.201.64.106:2380 \
 --listen-client-urls http://10.201.64.106:2379,http://127.0.0.1:2379 \
 --advertise-client-urls http://10.201.64.106:2379 \
 --initial-cluster-token etcd-cluster-1 \
 --initial-cluster milano01=http://10.201.64.106:2380,milano02=http://10.201.64.107:2380,milano03=http://10.222.82.121:2380 \
 --initial-cluster-state new \
 --heartbeat-interval 1000 \
 --election-timeout 5000

</details>


### Etcd debug information (please run commands blow, feel free to obfuscate the IP address or FQDN in the output)

<details>

```console
$ etcdctl member list -w table
# paste output here

$ etcdctl --endpoints=<member list> endpoint status -w table
# paste output here

Relevant log output

No response