Unstable Kudu Master

[#1]

Hello,

In my 3Masters cluster, one Kudu Master is starting and stopping all the time, this is the Log detail from Cloudera Manager: 

Time Log Level Source Log Message
10:14:41.417 AM WARN cc:288
Found duplicates in --master_addresses: the unique set of addresses is Master1:7051, Master2:7051, Master3:7051
10:15:11.823 AM WARN cc:254
Call kudu.consensus.ConsensusService.RequestConsensusVote from 10.157.136.55:55402 (request call id 0) took 4542 ms (4.54 s). Client timeout 1775 ms (1.78 s)
10:15:11.823 AM WARN cc:254
Call kudu.consensus.ConsensusService.RequestConsensusVote from 10.157.136.37:59796 (request call id 0) took 30215 ms (30.2 s). Client timeout 9654 ms (9.65 s)
10:15:11.823 AM WARN cc:260
Trace:
1112 10:15:07.281146 (+ 0us) service_pool.cc:169] Inserting onto call queue
1112 10:15:07.281169 (+ 23us) service_pool.cc:228] Handling call
1112 10:15:11.823245 (+4542076us) inbound_call.cc:171] Queueing success response
Metrics: {"spinlock_wait_cycles":384}
10:15:11.823 AM WARN cc:260
Trace:
1112 10:14:41.607787 (+ 0us) service_pool.cc:169] Inserting onto call queue
1112 10:14:41.607839 (+ 52us) service_pool.cc:228] Handling call
1112 10:15:11.823242 (+30215403us) inbound_call.cc:171] Queueing success response
Metrics: {}
10:15:11.823 AM WARN cc:254
Call kudu.consensus.ConsensusService.RequestConsensusVote from 10.157.136.55:55402 (request call id 1) took 4536 ms (4.54 s). Client timeout 1955 ms (1.96 s)
10:15:11.823 AM WARN cc:260
Trace:
1112 10:15:07.286988 (+ 0us) service_pool.cc:169] Inserting onto call queue
1112 10:15:07.287025 (+ 37us) service_pool.cc:228] Handling call
1112 10:15:11.823244 (+4536219us) inbound_call.cc:171] Queueing success response
Metrics: {}

What does it means???

why is this so unconsistent?