实战案例：基于Redis 5 的 redis cluster 部署
官方文档：https://redis.io/topics/cluster-tutorial
redis cluster 相关命令
[root@redis-node1 ~]# redis-cli --cluster help
Cluster Manager Commands:
create host1:port1 ... hostN:portN
--cluster-replicas <arg>
check host:port
--cluster-search-multiple-owners
info host:port
fix host:port
--cluster-search-multiple-owners
reshard host:port
--cluster-from <arg>
--cluster-to <arg>
--cluster-slots <arg>
--cluster-yes
--cluster-timeout <arg>
--cluster-pipeline <arg>
--cluster-replace
rebalance host:port
--cluster-weight <node1=w1...nodeN=wN>
--cluster-use-empty-masters
--cluster-timeout <arg>
--cluster-simulate
--cluster-pipeline <arg>
--cluster-threshold <arg>
--cluster-replace
add-node new_host:new_port existing_host:existing_port
--cluster-slave
--cluster-master-id <arg>
del-node host:port node_id
call host:port command arg arg .. arg
set-timeout host:port milliseconds
import host:port
--cluster-from <arg>
--cluster-copy
--cluster-replace
help
For check, fix, reshard, del-node, set-timeout you can specify the host and port of any working node in the cluster.
[root@redis-node1 ~]#redis-cli -a 123456 CLUSTER HELP
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
1) CLUSTER <subcommand> arg arg ... arg. Subcommands are:
2) ADDSLOTS <slot> [slot ...] -- Assign slots to current node.
3) BUMPEPOCH -- Advance the cluster config epoch.
4) COUNT-failure-reports <node-id> -- Return number of failure reports for <node-id>.
5) COUNTKEYSINSLOT <slot> - Return the number of keys in <slot>.
6) DELSLOTS <slot> [slot ...] -- Delete slots information from current node.
7) FAILOVER [force|takeover] -- Promote current replica node to being a master.
8) FORGET <node-id> -- Remove a node from the cluster.
9) GETKEYSINSLOT <slot> <count> -- Return key names stored by current node in a slot.
10) FLUSHSLOTS -- Delete current node own slots information.
11) INFO - Return onformation about the cluster.
12) KEYSLOT <key> -- Return the hash slot for <key>.
13) MEET <ip> <port> [bus-port] -- Connect nodes into a working cluster.
14) MYID -- Return the node id.
15) NODES -- Return cluster configuration seen by node. Output format:
16) <id> <ip:port> <flags> <master> <pings> <pongs> <epoch> <link> <slot> ... <slot>
17) REPLICATE <node-id> -- Configure current node as replica to <node-id>.
18) RESET [hard|soft] -- Reset current node (default: soft).
19) SET-config-epoch <epoch> - Set config epoch of current node.
20) SETSLOT <slot> (importing|migrating|stable|node <node-id>) -- Set slot state.
21) REPLICAS <node-id> -- Return <node-id> replicas.
22) SLOTS -- Return information about slots range mappings. Each range is made of:
23) start, end, master and replicas IP addresses, ports and ids
创建redis cluster集群的环境准备
1.每个redis 节点采用相同的硬件配置、相同的密码、相同的redis版本
2.所有redis服务器必须没有任何数据
3.先启动为单机redis且没有任何key value
4.准备六台主机，地址如下：
10.0.0.8
10.0.0.18
10.0.0.28
10.0.0.38
10.0.0.48
10.0.0.58
10.0.0.68启用redis cluster 配置
所有6台主机都执行以下配置
[root@centos8 ~]#dnf -y install redis-每个节点修改redis配置，必须开启cluster功能的参数
#手动修改配置文件
[root@redis-node1 ~]vim /etc/redis.conf
masterauth 123456 #建议配置，否则后期的master和slave无法成功，还需再配置
requirepass 123456
cluster-enabled yes #必须开启集群状态，开启后redis 进程会有cluster显示
cluster-config-file nodes-6379.conf #此文件有redis cluster集群自动创建和维护
appendonly yes
#或者执行下面命令,批量修改
[root@redis-node1 ~]#sed -i.bak -e 's/bind 127.0.0.1/bind 0.0.0.0/' -e '/masterauth/a masterauth 123456' -e '/# requirepass/a requirepass 123456' -e '/# cluster-enabled yes/a cluster-enabled yes' -e '/# cluster-config-file nodes-6379.conf/a cluster-config-file nodes-6379.conf' -e '/appendonly no/c appendonly yes' /etc/redis.conf
[root@redis-node1 ~]#systemctl restart redis-验证当前Redis服务状态：
#开启了16379的cluster的端口
[root@centos8 ~]#ss -ntl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
LISTEN 0 100 127.0.0.1:25 0.0.0.0:*
LISTEN 0 128 0.0.0.0:16379 0.0.0.0:*
LISTEN 0 128 0.0.0.0:6379 0.0.0.0:*
LISTEN 0 128 [::]:22 [::]:*
LISTEN 0 100 [::1]:25 [::]:*
#注意进程的状态
[root@centos8 ~]#ps -ef|grep redis
redis 1939 1 0 10:54 ? 00:00:00 /usr/bin/redis-server 0.0.0.0:6379 [cluster]
root 1955 1335 0 10:57 pts/0 00:00:00 grep --color=auto redis创建集群
# --cluster-replicas 1 表示每个master对应一个slave节点
[root@redis-node1 ~]#redis-cli -a 123456 --cluster create 10.0.0.8:6379 10.0.0.18:6379 10.0.0.28:6379 10.0.0.38:6379 10.0.0.48:6379 10.0.0.58:6379 --cluster-replicas 1
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
>>> Performing hash slots allocation on 6 nodes...
Master[0] -> Slots 0 - 5460
Master[1] -> Slots 5461 - 10922
Master[2] -> Slots 10923 - 16383
Adding replica 10.0.0.38:6379 to 10.0.0.8:6379
Adding replica 10.0.0.48:6379 to 10.0.0.18:6379
Adding replica 10.0.0.58:6379 to 10.0.0.28:6379
M: cb028b83f9dc463d732f6e76ca6bbcd469d948a7 10.0.0.8:6379 #带M的为master
slots:[0-5460] (5461 slots) master #当前master的槽位起始和结束位
M: 99720241248ff0e4c6fa65c2385e92468b3b5993 10.0.0.18:6379
slots:[5461-10922] (5462 slots) master
M: d34da8666a6f587283a1c2fca5d13691407f9462 10.0.0.28:6379
slots:[10923-16383] (5461 slots) master
S: f9adcfb8f5a037b257af35fa548a26ffbadc852d 10.0.0.38:6379 #带S的slave
replicates cb028b83f9dc463d732f6e76ca6bbcd469d948a7
S: d04e524daec4d8e22bdada7f21a9487c2d3e1057 10.0.0.48:6379
replicates 99720241248ff0e4c6fa65c2385e92468b3b5993
S: 9875b50925b4e4f29598e6072e5937f90df9fc71 10.0.0.58:6379
replicates d34da8666a6f587283a1c2fca5d13691407f9462
Can I set the above configuration? (type 'yes' to accept): yes #输入yes自动创建集群
>>> Nodes configuration updated
>>> Assign a different config epoch to each node
>>> Sending CLUSTER MEET messages to join the cluster
Waiting for the cluster to join
....
>>> Performing Cluster Check (using node 10.0.0.8:6379)
M: cb028b83f9dc463d732f6e76ca6bbcd469d948a7 10.0.0.8:6379
slots:[0-5460] (5461 slots) master #已经分配的槽位
1 additional replica(s) #分配了一个slave
S: 9875b50925b4e4f29598e6072e5937f90df9fc71 10.0.0.58:6379
slots: (0 slots) slave #slave没有分配槽位
replicates d34da8666a6f587283a1c2fca5d13691407f9462 #对应的master的10.0.0.28的ID
S: f9adcfb8f5a037b257af35fa548a26ffbadc852d 10.0.0.38:6379
slots: (0 slots) slave
replicates cb028b83f9dc463d732f6e76ca6bbcd469d948a7 #对应的master的10.0.0.8的ID
S: d04e524daec4d8e22bdada7f21a9487c2d3e1057 10.0.0.48:6379
slots: (0 slots) slave
replicates 99720241248ff0e4c6fa65c2385e92468b3b5993 #对应的master的10.0.0.18的ID
M: 99720241248ff0e4c6fa65c2385e92468b3b5993 10.0.0.18:6379
slots:[5461-10922] (5462 slots) master
1 additional replica(s)
M: d34da8666a6f587283a1c2fca5d13691407f9462 10.0.0.28:6379
slots:[10923-16383] (5461 slots) master
1 additional replica(s)
[OK] All nodes agree about slots configuration. #所有节点槽位分配完成
>>> Check for open slots... #检查打开的槽位
>>> Check slots coverage... #检查插槽覆盖范围
[OK] All 16384 slots covered. #所有槽位(16384个)分配完成
[root@redis-node1 ~]#
观察以上结果，可以看到3组master/slave
master:10.0.0.8---slave:10.0.0.38
master:10.0.0.18---slave:10.0.0.48
master:10.0.0.28---slave:10.0.0.58查看主从状态
[root@redis-node1 ~]#redis-cli -a 123456 INFO replication
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
# Replication
role:master
connected_slaves:1
slave0:ip=10.0.0.38,port=6379,state=online,offset=896,lag=1
master_replid:3a388865080d779180ff240cb75766e7e57877da
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:896
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:896
[root@redis-node2 ~]#redis-cli -a 123456 INFO replication
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
# Replication
role:master
connected_slaves:1
slave0:ip=10.0.0.48,port=6379,state=online,offset=980,lag=1
master_replid:b9066d3cbf0c5fecc7f4d1d5cb2433999783fa3f
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:980
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:980
[root@redis-node3 ~]#redis-cli -a 123456 INFO replication
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
# Replication
role:master
connected_slaves:1
slave0:ip=10.0.0.58,port=6379,state=online,offset=980,lag=0
master_replid:53208e0ed9305d721e2fb4b3180f75c689217902
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:980
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:980
[root@redis-node4 ~]#redis-cli -a 123456 INFO replication
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
# Replication
role:slave
master_host:10.0.0.8
master_port:6379
master_link_status:up
master_last_io_seconds_ago:1
master_sync_in_progress:0
slave_repl_offset:1036
slave_priority:100
slave_read_only:1
connected_slaves:0
master_replid:3a388865080d779180ff240cb75766e7e57877da
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:1036
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:1036
[root@redis-node5 ~]#redis-cli -a 123456 INFO replication
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
# Replication
role:slave
master_host:10.0.0.18
master_port:6379
master_link_status:up
master_last_io_seconds_ago:2
master_sync_in_progress:0
slave_repl_offset:1064
slave_priority:100
slave_read_only:1
connected_slaves:0
master_replid:b9066d3cbf0c5fecc7f4d1d5cb2433999783fa3f
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:1064
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:1064
[root@redis-node6 ~]#redis-cli -a 123456 INFO replication
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
# Replication
role:slave
master_host:10.0.0.28
master_port:6379
master_link_status:up
master_last_io_seconds_ago:7
master_sync_in_progress:0
slave_repl_offset:1078
slave_priority:100
slave_read_only:1
connected_slaves:0
master_replid:53208e0ed9305d721e2fb4b3180f75c689217902
master_replid2:0000000000000000000000000000000000000000
master_repl_offset:1078
second_repl_offset:-1
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1
repl_backlog_histlen:1078验证集群状态
[root@redis-node1 ~]#redis-cli -a 123456 CLUSTER INFO
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
cluster_state:ok
cluster_slots_assigned:16384
cluster_slots_ok:16384
cluster_slots_pfail:0
cluster_slots_fail:0
cluster_known_nodes:6 #节点数
cluster_size:3 #三个集群
cluster_current_epoch:6
cluster_my_epoch:1
cluster_stats_messages_ping_sent:837
cluster_stats_messages_pong_sent:811
cluster_stats_messages_sent:1648
cluster_stats_messages_ping_received:806
cluster_stats_messages_pong_received:837
cluster_stats_messages_meet_received:5
cluster_stats_messages_received:1648
#查看任意节点的集群状态
[root@redis-node1 ~]#redis-cli -a 123456 --cluster info 10.0.0.38:6379
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
10.0.0.18:6379 (99720241...) -> 0 keys | 5462 slots | 1 slaves.
10.0.0.28:6379 (d34da866...) -> 0 keys | 5461 slots | 1 slaves.
10.0.0.8:6379 (cb028b83...) -> 0 keys | 5461 slots | 1 slaves.
[OK] 0 keys in 3 masters.
0.00 keys per slot on average.
查看集群node对应关系
[root@redis-node1 ~]#redis-cli -a 123456 CLUSTER NODES
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
9875b50925b4e4f29598e6072e5937f90df9fc71 10.0.0.58:6379@16379 slave d34da8666a6f587283a1c2fca5d13691407f9462 0 1582344815790 6 connected
f9adcfb8f5a037b257af35fa548a26ffbadc852d 10.0.0.38:6379@16379 slave cb028b83f9dc463d732f6e76ca6bbcd469d948a7 0 1582344811000 4 connected
d04e524daec4d8e22bdada7f21a9487c2d3e1057 10.0.0.48:6379@16379 slave 99720241248ff0e4c6fa65c2385e92468b3b5993 0 1582344815000 5 connected
99720241248ff0e4c6fa65c2385e92468b3b5993 10.0.0.18:6379@16379 master - 0 1582344813000 2 connected 5461-10922
d34da8666a6f587283a1c2fca5d13691407f9462 10.0.0.28:6379@16379 master - 0 1582344814780 3 connected 10923-16383
cb028b83f9dc463d732f6e76ca6bbcd469d948a7 10.0.0.8:6379@16379 myself,master - 0 1582344813000 1 connected 0-5460
[root@redis-node1 ~]#redis-cli -a 123456 --cluster check 10.0.0.38:6379
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
10.0.0.18:6379 (99720241...) -> 0 keys | 5462 slots | 1 slaves.
10.0.0.28:6379 (d34da866...) -> 0 keys | 5461 slots | 1 slaves.
10.0.0.8:6379 (cb028b83...) -> 0 keys | 5461 slots | 1 slaves.
[OK] 0 keys in 3 masters.
0.00 keys per slot on average.
>>> Performing Cluster Check (using node 10.0.0.38:6379)
S: f9adcfb8f5a037b257af35fa548a26ffbadc852d 10.0.0.38:6379
slots: (0 slots) slave
replicates cb028b83f9dc463d732f6e76ca6bbcd469d948a7
S: d04e524daec4d8e22bdada7f21a9487c2d3e1057 10.0.0.48:6379
slots: (0 slots) slave
replicates 99720241248ff0e4c6fa65c2385e92468b3b5993
M: 99720241248ff0e4c6fa65c2385e92468b3b5993 10.0.0.18:6379
slots:[5461-10922] (5462 slots) master
1 additional replica(s)
S: 9875b50925b4e4f29598e6072e5937f90df9fc71 10.0.0.58:6379
slots: (0 slots) slave
replicates d34da8666a6f587283a1c2fca5d13691407f9462
M: d34da8666a6f587283a1c2fca5d13691407f9462 10.0.0.28:6379
slots:[10923-16383] (5461 slots) master
1 additional replica(s)
M: cb028b83f9dc463d732f6e76ca6bbcd469d948a7 10.0.0.8:6379
slots:[0-5460] (5461 slots) master
1 additional replica(s)
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.
验证集群写入key
#经过算法计算，当前key的槽位需要写入指定的node
[root@redis-node1 ~]#redis-cli -a 123456 -h 10.0.0.8 SET key1 values1
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
(error) MOVED 9189 10.0.0.18:6379 #槽位不在当前node所以无法写入
[root@redis-node1 ~]#redis-cli -a 123456 -h 10.0.0.18 SET key1 values1
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
OK
#指定node可写入
[root@redis-node1 ~]#redis-cli -a 123456 -h 10.0.0.18 GET key1
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
"values1"
#对应的slave节点可以KEYS *,但GET key1失败
[root@redis-node1 ~]#redis-cli -a 123456 -h 10.0.0.48 KEYS "*"
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
1) "key1"
[root@redis-node1 ~]#redis-cli -a 123456 -h 10.0.0.48 GET key1
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
(error) MOVED 9189 10.0.0.18:6379python脚本实现RedisCluster集群写入
[root@redis-node1 ~]#dnf -y install python3
[root@redis-node1 ~]#pip3 install redis-py-cluster
[root@redis-node1 ~]#vim redis_cluster_test.py
[root@redis-node1 ~]#cat ./redis_cluster_test.py
#!/usr/bin/env python3
from rediscluster import RedisCluster
startup_nodes = [
{"host":"10.0.0.8", "port":6379},
{"host":"10.0.0.18", "port":6379},
{"host":"10.0.0.28", "port":6379},
{"host":"10.0.0.38", "port":6379},
{"host":"10.0.0.48", "port":6379},
{"host":"10.0.0.58", "port":6379}
]
redis_conn= RedisCluster(startup_nodes=startup_nodes,password='123456', decode_responses=True)
for i in range(0, 10000):
redis_conn.set('key'+str(i),'value'+str(i))
print('key'+str(i)+':',redis_conn.get('key'+str(i)))
[root@redis-node1 ~]#chmod +x redis_cluster_test.py
[root@redis-node1 ~]#./redis_cluster_test.py
......
key9998: value9998
key9999: value9999
[root@redis-node1 ~]#redis-cli -a 123456 -h 10.0.0.8
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
10.0.0.8:6379> DBSIZE
(integer) 3331
10.0.0.8:6379> GET key1
(error) MOVED 9189 10.0.0.18:6379
10.0.0.8:6379> GET key2
"value2"
10.0.0.8:6379> GET key3
"value3"
10.0.0.8:6379> KEYS *
......
3329) "key7832"
3330) "key2325"
3331) "key2880"
10.0.0.8:6379>
[root@redis-node1 ~]#redis-cli -a 123456 -h 10.0.0.18 DBSIZE
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
(integer) 3340
[root@redis-node1 ~]#redis-cli -a 123456 -h 10.0.0.18 GET key1
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
"value1"
[root@redis-node1 ~]#redis-cli -a 123456 -h 10.0.0.28 DBSIZE
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
(integer) 3329
[root@redis-node1 ~]#redis-cli -a 123456 -h 10.0.0.18 GET key5
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
"value5"
[root@redis-node1 ~]#
模拟master故障，对应的slave节点自动提升为新master
#模拟node2节点出故障,需要相应的数秒故障转移时间
[root@redis-node2 ~]#tail -f /var/log/redis/redis.log
[root@redis-node2 ~]#redis-cli -a 123456
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
127.0.0.1:6379> shutdown
not connected> exit
[root@redis-node2 ~]#ss -ntl
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
LISTEN 0 100 127.0.0.1:25 0.0.0.0:*
LISTEN 0 128 [::]:22 [::]:*
LISTEN 0 100 [::1]:25 [::]:*
[root@redis-node2 ~]# redis-cli -a 123456 --cluster info 10.0.0.8:6379
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
Could not connect to Redis at 10.0.0.18:6379: Connection refused
10.0.0.8:6379 (cb028b83...) -> 3331 keys | 5461 slots | 1 slaves.
10.0.0.48:6379 (d04e524d...) -> 3340 keys | 5462 slots | 0 slaves. #10.0.0.48为新的master
10.0.0.28:6379 (d34da866...) -> 3329 keys | 5461 slots | 1 slaves.
[OK] 10000 keys in 3 masters.
0.61 keys per slot on average.
[root@redis-node2 ~]# redis-cli -a 123456 --cluster check 10.0.0.8:6379
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
Could not connect to Redis at 10.0.0.18:6379: Connection refused
10.0.0.8:6379 (cb028b83...) -> 3331 keys | 5461 slots | 1 slaves.
10.0.0.48:6379 (d04e524d...) -> 3340 keys | 5462 slots | 0 slaves.
10.0.0.28:6379 (d34da866...) -> 3329 keys | 5461 slots | 1 slaves.
[OK] 10000 keys in 3 masters.
0.61 keys per slot on average.
>>> Performing Cluster Check (using node 10.0.0.8:6379)
M: cb028b83f9dc463d732f6e76ca6bbcd469d948a7 10.0.0.8:6379
slots:[0-5460] (5461 slots) master
1 additional replica(s)
S: 9875b50925b4e4f29598e6072e5937f90df9fc71 10.0.0.58:6379
slots: (0 slots) slave
replicates d34da8666a6f587283a1c2fca5d13691407f9462
S: f9adcfb8f5a037b257af35fa548a26ffbadc852d 10.0.0.38:6379
slots: (0 slots) slave
replicates cb028b83f9dc463d732f6e76ca6bbcd469d948a7
M: d04e524daec4d8e22bdada7f21a9487c2d3e1057 10.0.0.48:6379
slots:[5461-10922] (5462 slots) master
M: d34da8666a6f587283a1c2fca5d13691407f9462 10.0.0.28:6379
slots:[10923-16383] (5461 slots) master
1 additional replica(s)
[OK] All nodes agree about slots configuration.
>>> Check for open slots...
>>> Check slots coverage...
[OK] All 16384 slots covered.
[root@redis-node2 ~]#redis-cli -a 123456 -h 10.0.0.48
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
10.0.0.48:6379> INFO replication
# Replication
role:master
connected_slaves:0
master_replid:0000698bc2c6452d8bfba68246350662ae41d8fd
master_replid2:b9066d3cbf0c5fecc7f4d1d5cb2433999783fa3f
master_repl_offset:2912424
second_repl_offset:2912425
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1863849
repl_backlog_histlen:1048576
10.0.0.48:6379>
#恢复故障节点node2
[root@redis-node2 ~]#systemctl start redis
#查看自动生成的配置文件，可以查看node2自动成为slave节点
[root@redis-node2 ~]#cat /var/lib/redis/nodes-6379.conf
99720241248ff0e4c6fa65c2385e92468b3b5993 10.0.0.18:6379@16379 myself,slave d04e524daec4d8e22bdada7f21a9487c2d3e1057 0 1582352081847 2 connected
f9adcfb8f5a037b257af35fa548a26ffbadc852d 10.0.0.38:6379@16379 slave cb028b83f9dc463d732f6e76ca6bbcd469d948a7 1582352081868 1582352081847 4 connected
cb028b83f9dc463d732f6e76ca6bbcd469d948a7 10.0.0.8:6379@16379 master - 1582352081868 1582352081847 1 connected 0-5460
9875b50925b4e4f29598e6072e5937f90df9fc71 10.0.0.58:6379@16379 slave d34da8666a6f587283a1c2fca5d13691407f9462 1582352081869 1582352081847 3 connected
d04e524daec4d8e22bdada7f21a9487c2d3e1057 10.0.0.48:6379@16379 master - 1582352081869 1582352081847 7 connected 5461-10922
d34da8666a6f587283a1c2fca5d13691407f9462 10.0.0.28:6379@16379 master - 1582352081869 1582352081847 3 connected 10923-16383
vars currentEpoch 7 lastVoteEpoch 0
[root@redis-node2 ~]#redis-cli -a 123456 -h 10.0.0.48
Warning: Using a password with '-a' or '-u' option on the command line interface may not be safe.
10.0.0.48:6379> INFO replication
# Replication
role:master
connected_slaves:1
slave0:ip=10.0.0.18,port=6379,state=online,offset=2912564,lag=1
master_replid:0000698bc2c6452d8bfba68246350662ae41d8fd
master_replid2:b9066d3cbf0c5fecc7f4d1d5cb2433999783fa3f
master_repl_offset:2912564
second_repl_offset:2912425
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:1863989
repl_backlog_histlen:1048576
10.0.0.48:6379>
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