Multiple dm-master become leader at the same time

[GMHDBJD]

What did you do?

kill dm leader

What did you expect to see?

one dm-master becomes leader

What did you see instead?

two dm-master become leader at the same time
dm-master1:

[2024/08/14 23:16:47.974 +00:00] [INFO] [election.go:273] ["successful manually clean election key"] [component=election] ["campaign error"="rpc error: code = Unknown desc = malformed header: missing HTTP content-type"]
[2024/08/14 23:16:47.975 +00:00] [INFO] [election.go:278] ["fail to campaign"] [component=election] ["current member"="{\"id\":\"xxx\",\"addr\":\"xxx-dm-master-1.xxx-dm-master-peer:8261\"}"] [error="rpc error: code = Unknown desc = malformed header: missing HTTP content-type"]
[2024/08/14 23:16:47.975 +00:00] [INFO] [election.go:300] ["get response from election observe"] [component=election] [key=/dm-master/leader/76e2914ca9fdb304] [value="{\"id\":\"xxx-dm-master-1\",\"addr\":\"xxx-dm-master-1.xxx-dm-master-peer:8261\"}"]
[2024/08/14 23:16:47.975 +00:00] [INFO] [election.go:331] ["become leader"] [component=election] ["current member"="{\"id\":\"xxx-dm-master-1\",\"addr\":\"xxx-dm-master-1.xxx-dm-master-peer:8261\"}"]

[2024/08/14 23:16:47.975 +00:00] [INFO] [election.go:331] ["become leader"] [component=election] ["current member"="{\"id\":\"xxx\",\"addr\":\"xxx-dm-master-1.xxx-dm-master-peer:8261\"}"]
dm-master-0: [2024/08/14 23:16:48.045 +00:00] [INFO] [election.go:331] ["become leader"] [component=election] ["current member"="{\"id\":\"xxx-dm-master-0\",\"addr\":\"xxx-dm-master-0.xxx-dm-master-peer:8261\"}"]

Versions of the cluster

DM version (run dmctl -V or dm-worker -V or dm-master -V):

(paste DM version here, and you must ensure versions of dmctl, DM-worker and DM-master are same)

Upstream MySQL/MariaDB server version:

(paste upstream MySQL/MariaDB server version here)

Downstream TiDB cluster version (execute SELECT tidb_version(); in a MySQL client):

(paste TiDB cluster version here)

How did you deploy DM: tiup or manually?

(leave TiUP or manually here)

Other interesting information (system version, hardware config, etc):

>
>

current status of DM cluster (execute query-status <task-name> in dmctl)

(paste current status of DM cluster here)