1.现状描述
集群其中一台物理机未知原因导致单用户无法登陆机器，该物理机需要重启修改密码或者重装系统。该台为master节点，运行正常。
配置策略为：
-
异步刷盘
-
主从异步复制
如果直接下线该master，由于主从异步复制，可能导致部分消息来不及复制到slave造成消息丢失。所以该方案不可行。
另一种方案选择：关闭该broker的写入权限，待该broker不再有写入和消费时，再下线该节点。
2.关闭broker写权限
2表示只写权限，4表示只读权限，6表示读写权限
bin/mqadmin updateBrokerConfig -b 192.168.x.x:10911 -n 192.168.x.x:9876 -k brokerPermission -v 4
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=128m; support was removed in 8.0
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=128m; support was removed in 8.0
update broker config success, 192.168.x.x:10911
3.观察节点流量
bin/mqadmin clusterList -n 192.168.x.x:9876
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=128m; support was removed in 8.0
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=128m; support was removed in 8.0
#Cluster Name #Broker Name #BID #Addr #Version #InTPS(LOAD) #OutTPS(LOAD) #PCWait(ms) #Hour #SPACE
ZmsClusterA broker-a 0 192.168.x.x:10911 V4_1_0_SNAPSHOT 2492.95(0,0ms) 2269.27(1,0ms) 0 137.57 0.1861
ZmsClusterA broker-a 1 192.168.x.x:10911 V4_1_0_SNAPSHOT 2485.45(0,0ms) 0.00(0,0ms) 0 125.26 0.3055
ZmsClusterA broker-b 0 192.168.x.x:10911 V4_1_0_SNAPSHOT 26.47(0,0ms) 26.08(0,0ms) 0 137.24 0.1610
ZmsClusterA broker-b 1 192.168.x.x:10915 V4_1_0_SNAPSHOT 20.47(0,0ms) 0.00(0,0ms) 0 125.22 0.3055
ZmsClusterA broker-c 0 192.168.x.x:10911 V4_1_0_SNAPSHOT 2061.09(0,0ms) 1967.30(0,0ms) 0 125.28 0.2031
ZmsClusterA broker-c 1 192.168.x.x:10911 V4_1_0_SNAPSHOT 2048.20(0,0ms) 0.00(0,0ms) 0 137.51 0.2789
ZmsClusterA broker-d 0 192.168.x.x:10911 V4_1_0_SNAPSHOT 2017.40(0,0ms) 1788.32(0,0ms) 0 125.22 0.1261
ZmsClusterA broker-d 1 192.168.x.x:10915 V4_1_0_SNAPSHOT 2026.50(0,0ms) 0.00(0,0ms) 0 137.61 0.2789
观察InTPS和OutTPS，理想情况都为零时，并不再变化时，则该节点可下线了。
然而，在实际过程中并没有出现为零的情况，InTPS和OutTPS总是有值，有时个位数字有时是两位数字，大部分时间在20多的值。此刻要分析下broker目前的消费状态。
4.观察broker消费状态
sh bin/mqadmin brokerConsumeStats -b 192.168.x.x:10911 -n 192.168.x.x:9876 >> brokerConsumeStats.tmp
查看brokerConsumeStats.tmp，主要查看#LastTime和#Diff。发现%RETRY%重试类队列#Diff有很微小（1或者3）的数据，而其他topic均为0. LastTime时间最新也是发生在%RETRY%队列中。此时可以让该节点下线操作。
#Topic #Group #Broker Name #QID #Broker Offset #Consumer Offset #Diff #LastTime
SV_Multi_Message ZTO_SV_EmchatWebConsumerGroup broker-b 0 2171742 2171742 0 2019-04-24 23:38:09
SV_Multi_Message ZTO_SV_EmchatWebConsumerGroup broker-b 1 2171756 2171756 0 2019-04-24 23:38:50
SV_Multi_Message ZTO_SV_EmchatWebConsumerGroup broker-b 2 2171740 2171740 0 2019-04-24 23:42:58
SV_Multi_Message ZTO_SV_EmchatWebConsumerGroup broker-b 3 2171759 2171759 0 2019-04-24 23:40:44
SV_Multi_Message ZTO_SV_EmchatWebConsumerGroup broker-b 4 2171743 2171743 0 2019-04-24 23:32:48
SV_Multi_Message ZTO_SV_EmchatWebConsumerGroup broker-b 5 2171740 2171740 0 2019-04-24 23:35:58
SV_Multi_Message ZTO_SV_EmchatWebConsumerGroup broker-b 6 2171758 2171758 0 2019-04-24 23:36:23
SV_Multi_Message ZTO_SV_EmchatWebConsumerGroup broker-b 7 2171740 2171740 0 2019-04-24 23:37:50
%RETRY%ZTO_SV_EmchatWebConsumerG ZTO_SV_EmchatWebConsumerGroup broker-b 0 61876 61876 0 2019-04-24 10:09:04
%RETRY%SVC_TRACK_CONSUMER SVC_TRACK_CONSUMER broker-b 0 497968 497968 0 2019-04-19 12:51:24
SVC_TRACK_TOPIC SVC_TRACK_CONSUMER broker-b 0 191710 191710 0 2019-04-24 23:44:22
SVC_TRACK_TOPIC SVC_TRACK_CONSUMER broker-b 1 191706 191706 0 2019-04-24 23:44:25
SVC_TRACK_TOPIC SVC_TRACK_CONSUMER broker-b 2 191697 191697 0 2019-04-24 23:44:44
SVC_TRACK_TOPIC SVC_TRACK_CONSUMER broker-b 3 191695 191695 0 2019-04-24 23:44:47
SVC_TRACK_TOPIC SVC_TRACK_CONSUMER broker-b 4 191688 191688 0 2019-04-24 23:44:47
SVC_TRACK_TOPIC SVC_TRACK_CONSUMER broker-b 5 191683 191683 0 2019-04-24 23:44:48
SVC_TRACK_TOPIC SVC_TRACK_CONSUMER broker-b 6 191676 191676 0 2019-04-24 23:44:49
SVC_TRACK_TOPIC SVC_TRACK_CONSUMER broker-b 7 191672 191672 0 2019-04-24 23:44:49
5.borker读写权限恢复
bin/mqadmin updateBrokerConfig -b 192.168.x.x:10911 -n 192.168.x.x:9876 -k brokerPermission -v 6
观察各节点流量是否正常
bin/mqadmin clusterList -n 192.168.x.x:9876
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option PermSize=128m; support was removed in 8.0
Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=128m; support was removed in 8.0
#Cluster Name #Broker Name #BID #Addr #Version #InTPS(LOAD) #OutTPS(LOAD) #PCWait(ms) #Hour #SPACE
ZmsClusterA broker-a 0 192.168.x.x:10911 V4_1_0_SNAPSHOT 2492.95(0,0ms) 2269.27(1,0ms) 0 137.57 0.1861
ZmsClusterA broker-a 1 192.168.x.x:10911 V4_1_0_SNAPSHOT 2485.45(0,0ms) 0.00(0,0ms) 0 125.26 0.3055
ZmsClusterA broker-b 0 192.168.x.x:10911 V4_1_0_SNAPSHOT 2299.47(0,0ms) 2226.08(0,0ms) 0 137.24 0.1610
ZmsClusterA broker-b 1 192.168.x.x:10915 V4_1_0_SNAPSHOT 2280.47(0,0ms) 0.00(0,0ms) 0 125.22 0.3055
ZmsClusterA broker-c 0 192.168.x.x:10911 V4_1_0_SNAPSHOT 2061.09(0,0ms) 1967.30(0,0ms) 0 125.28 0.2031
ZmsClusterA broker-c 1 192.168.x.x:10911 V4_1_0_SNAPSHOT 2048.20(0,0ms) 0.00(0,0ms) 0 137.51 0.2789
ZmsClusterA broker-d 0 192.168.x.x:10911 V4_1_0_SNAPSHOT 2017.40(0,0ms) 1788.32(0,0ms) 0 125.22 0.1261
ZmsClusterA broker-d 1 192.168.x.x:10915 V4_1_0_SNAPSHOT 2026.50(0,0ms) 0.00(0,0ms)