My doubt: Is it true that when there are only two alphas in group2, after zero removes one of the alphas, the alpha-3 in group2 is not perceptible, resulting in the original raft member 0x9 being sent a message but not received The reply caused the subsequent request to be ignored.
alpha-3 log：
I0514 08:01:06.482733 22 node.go:586] Trying to add 0xc to cluster. Addr: dgraph-alpha-4.dgraph-alpha.crm-test.svc.cluster.local:7080
I0514 08:01:06.482749 22 node.go:587] Current confstate at 0x8: nodes:8 nodes:9
I0514 08:01:06.777035 22 log.go:34] 8 is starting a new election at term 29
I0514 08:01:06.777059 22 log.go:34] 8 became pre-candidate at term 29
I0514 08:01:06.777064 22 log.go:34] 8 received MsgPreVoteResp from 8 at term 29
I0514 08:01:06.777079 22 log.go:34] 8 [logterm: 29, index: 62573422] sent MsgPreVote request to 9 at term 29
I0514 08:01:06.777126 22 node.go:258] RaftComm: [0x8] Sending message of type MsgPreVote to 0x9
I0514 08:01:09.482903 22 node.go:586] Trying to add 0xc to cluster. Addr: dgraph-alpha-4.dgraph-alpha.crm-test.svc.cluster.local:7080
I0514 08:01:09.482930 22 node.go:587] Current confstate at 0x8: nodes:8 nodes:9
I0514 08:01:10.177031 22 log.go:34] 8 is starting a new election at term 29
I0514 08:01:10.177051 22 log.go:34] 8 became pre-candidate at term 29
I0514 08:01:10.177056 22 log.go:34] 8 received MsgPreVoteResp from 8 at term 29
I0514 08:01:10.177078 22 log.go:34] 8 [logterm: 29, index: 62573422] sent MsgPreVote request to 9 at term 29
I0514 08:01:10.177119 22 node.go:258] RaftComm: [0x8] Sending message of type MsgPreVote to 0x9
I0514 08:01:12.483026 22 node.go:586] Trying to add 0xc to cluster. Addr: dgraph-alpha-4.dgraph-alpha.crm-test.svc.cluster.local:7080
I0514 08:01:12.483047 22 node.go:587] Current confstate at 0x8: nodes:8 nodes:9
I0514 08:01:13.577030 22 log.go:34] 8 is starting a new election at term 29
I0514 08:01:13.577054 22 log.go:34] 8 became pre-candidate at term 29
I0514 08:01:13.577059 22 log.go:34] 8 received MsgPreVoteResp from 8 at term 29
I0514 08:01:13.577082 22 log.go:34] 8 [logterm: 29, index: 62573422] sent MsgPreVote request to 9 at term 29
I0514 08:01:13.577132 22 node.go:258] RaftComm: [0x8] Sending message of type MsgPreVote to 0x9
W0514 08:01:14.577278 22 node.go:420] Unable to send message to peer: 0x9. Error: Do not have address of peer 0x9
alpha-4 log：
I0514 08:07:40.271103 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:07:45.271590 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:07:50.271731 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:07:55.271872 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:00.272015 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:05.272163 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:10.272317 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:15.272403 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:20.272545 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:25.272698 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:30.272845 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:35.272985 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:40.273123 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:45.273258 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
I0514 08:08:50.273398 21 admin.go:686] Error reading GraphQL schema: Please retry again, server is not ready to accept requests.
The above is the latest alpha-3 and alpha4 log information. Alpha-3 will also continue to send election messages to the old 0x9, because 0x9 has been removed by zero, resulting in election failure, so group2 currently does not have a leader, and query and mutation services are still unavailable. And because there is no timeout limit for joining the cluster, the new alpha-4 has not yet tried to join the cluster, but it still fails.
