raftexample deletes nodes and adds old nodes abnormally

[ws-weisb]

Bug report criteria

• This bug report is not security related, security issues should be disclosed privately via etcd maintainers.
• This is not a support request or question, support requests or questions should be raised in the etcd discussion forums.
• You have read the etcd bug reporting guidelines.
• Existing open issues along with etcd frequently asked questions have been checked and this is not a duplicate.

What happened?

raftexample

Q1: Deleting the data on the deleted machine is useless, will replay synced data after restart. All machine configurations need to be removed. Is this expected?

relation issue #15380 (comment)_

steps:

1. run cluster by Procfile
2. curl DELETE /3 on ID 1
3. curl POST /3 on ID 1
4. rm -fr raftexample-3*
5. restart ID 3 by same command

Q2: Why #13645 is not included in v3.5.16
tag v3.5.16

What did you expect to happen?

Q1: only delete the data of the previously removed nodes instead of all nodes
Q2: don't panic when remove unknown id, the previous commit should be in v3.5.16

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

Q1:
run raftexample on v3.5.16

1. run cluster by Procfile
2. curl DELETE /3 on ID 1
3. curl POST /3 on ID 1
4. rm -fr raftexample-3*
5. restart ID 3 by same command

Q2:
run raftexample on v3.5.16
curl DELETE /4 on any node

Anything else we need to know?

No response

Etcd version (please run commands below)

git tag v3.5.16

$ etcd --version
no

$ etcdctl version
no

Etcd configuration (command line flags or environment variables)

paste your configuration here

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

$ etcdctl member list -w table
# paste output here

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

Relevant log output

No response

[ahrtr]

Q1: Deleting the data on the deleted machine is useless, will replay synced data after restart. All machine configurations need to be removed. Is this expected?

It should be expected. A new member will sync data from other members automatically on startup. Note that we are not actively maintaining raftexample. Once etcd-io/raft#2 is resolved, then we will remove it from etcd repo.

Q2: Why #13645 is not included in v3.5.16

Note that issue #13466 could only be reproduced in 3.5.0. So no need to backport the fix to release-3.5. Read https://github.com/ahrtr/etcd-issues/tree/master/issues/13466

But It seems that you are still talking about raftexample.

[maxiloEmmmm]

@ahrtr That’s right. Q2 still refers to raftexample. Is this error still possible in 3.5.16 because raftexample is not maintained?