同一个组中只能添加一个redis实例

codis版本：3.2-redis-4.0.1
redis版本：3.2.9
具体情况：
刚开始如上所示，group3下有一个redis实例，再往group3添加一个实例，具体为192.168.1.150:6479

redis实例日志如下：
62206:M 13 Aug 17:18:26.368 # User requested shutdown...
62206:M 13 Aug 17:18:26.368 * Saving the final RDB snapshot before exiting.
62206:M 13 Aug 17:18:26.371 * DB saved on disk
62206:M 13 Aug 17:18:26.371 * Removing the pid file.
62206:M 13 Aug 17:18:26.371 # Redis is now ready to exit, bye bye...

codis日志如下：
2017/08/13 17:18:26 main.go:242: [WARN] [X] group-3 [1] 192.168.1.150:6479
2017/08/13 17:18:26 main.go:286: [WARN] try to group-del-server to dashboard 192.168.1.150:6479
2017/08/13 17:18:26 main.go:294: [WARN] try to shutdown codis-server(slave) 192.168.1.150:6479
2017/08/13 17:18:26 main.go:302: [WARN] try to shutdown codis-server 192.168.1.150:6479 failed
[error]: EOF
3 /root/go/src/github.com/CodisLabs/codis/pkg/utils/redis/client.go:57
github.com/CodisLabs/codis/pkg/utils/redis.(*Client).Do
2 /root/go/src/github.com/CodisLabs/codis/pkg/utils/redis/client.go:105
github.com/CodisLabs/codis/pkg/utils/redis.(*Client).Shutdown
1 /usr/local/gopkg/src/github.com/CodisLabs/codis/cmd/ha/main.go:301
main.(*HealthyChecker).Maintains
0 /usr/local/gopkg/src/github.com/CodisLabs/codis/cmd/ha/main.go:95
main.main
... ...

dashboard日志如下：
2017/08/13 17:18:26 topom_api.go:46: [WARN] [0xc420320360] API call /api/topom/group/del/95b62887719520f17e312eaa76d28f2b/3/192.168.1.150:6479 from 192.168.1.152:40034 []
2017/08/13 17:18:26 topom_api.go:46: [WARN] [0xc420320360] API call /api/topom/group/del/95b62887719520f17e312eaa76d28f2b/3/192.168.1.150:6479 from 192.168.1.151:41947 []
2017/08/13 17:18:26 topom_group.go:529: [WARN] server-[192.168.1.151:6480] action prepare
2017/08/13 17:18:26 topom_cache.go:179: [WARN] update group-[3]:
{
"id": 3,
"servers": [
{
"server": "192.168.1.151:6480",
"datacenter": "",
"action": {
"state": "syncing"
},
"replica_group": true
}
],
"promoting": {},
"out_of_sync": false
}
2017/08/13 17:18:26 topom_action.go:111: [WARN] sync-[192.168.1.151:6480] process action
2017/08/13 17:18:26 topom_group.go:557: [WARN] server-[192.168.1.151:6480] action failed = false
2017/08/13 17:18:26 topom_cache.go:179: [WARN] update group-[3]:
{
"id": 3,
"servers": [
{
"server": "192.168.1.151:6480",
"datacenter": "",
"action": {
"state": "synced"
},
"replica_group": true
}
],
"promoting": {},
"out_of_sync": false
}

看日志redis 192.168.1.151:6479是被客户端通知关闭的，这个是什么原因引起的？