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How to configure redis Master-Slave switch by keepalived

Shulou Source: shulou.com Published: 2022-06-01 10:50:23 10月14日 Update

This article introduces the knowledge of "how to configure redis master-slave switch in keepalived". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

IP Planning:

Master node: 10.0.37.224

Backup node: 10.0.37.225

VIP:10.0.37.226

One 2 nodes install redis

1 installation

[root@ray0redis02 ~] # wget http://download.redis.io/releases/redis-4.0.9.tar.gz

[root@ray0redis02 ~] # tar xzf redis-4.0.9.tar.gz

[root@ray0redis02 ~] # cd redis-4.0.9

[root@ray0redis02 ~] # make

[root@ray0redis02 ~] # make install

[root@ray0redis02] # mkdir-p / usr/local/redis/bin

[root@ray0redis02] # mkdir-p / usr/local/redis/etc

[root@ray0redis02 ~] # cp redis.conf / usr/local/redis/etc

[root@ray0redis02 ~] # cd src/

[root@ray0redis02 ~] # cp mkreleasehdr.sh redis-benchmark redis-check-aof redis-cli redis-server / usr/local/redis/bin

# [root@ray0redis02 ~] $vi / usr/local/redis/etc/redis.conf # change the value of daemonize to yes

[root@ray0redis02] # sed-I 's/daemonize no/daemonize yes/g' / usr/local/redis/etc/redis.conf

# start

[root@ray0redis02] # / usr/local/redis/bin/redis-server / usr/local/redis/etc/redis.conf

2 configure slave information of backup node

[root@ray0redis02 ~] # grep "^ slaveof" / usr/local/redis/etc/redis.conf

Slaveof 10.0.37.224 6379

# start

[root@ray0redis02] # / usr/local/redis/bin/redis-server / usr/local/redis/etc/redis.conf

Second, install keepalived

1 both nodes use yum to install keepalived

[root@ray0redis01 ~] # yum-y install keepalived

[root@ray0redis02 ~] # yum-y install keepalived

2 Primary Node keepalived configuration File

[root@ray0redis01 ~] # cat / etc/keepalived/keepalived.conf

! Configuration File for keepalived

Global_defs {

Router_id redis01

}

Vrrp_script chk_redis

{

Script "/ etc/keepalived/scripts/redis_check.sh"

Interval 2

Timeout 2

Fall 3

}

Vrrp_instance redis {

State MASTER

Interface ens192 # # needs to be modified to the name of the actual network card

Virtual_router_id 60

Priority 100 # # weight, the larger the number, the greater the weight, and the value of the primary node is larger than that of the standby node.

Advert_int 1

Authentication {# all node must same

Auth_type PASS

Auth_pass 1111

}

Virtual_ipaddress {

10.0.37.226 # need to modify the virtual IP that is actually assigned

}

Track_script {

Chk_redis

}

Notify_master "/ etc/keepalived/scripts/redis_master.sh 127.0.0.1 10.0.37.225 6379" # 10.0.37.225 needs to be modified to the actual remote host IP

Notify_backup "/ etc/keepalived/scripts/redis_backup.sh 127.0.0.1 10.0.37.225 6379" # 10.0.37.225 needs to be modified to the actual remote host IP

Notify_fault / etc/keepalived/scripts/redis_fault.sh

Notify_stop / etc/keepalived/scripts/redis_stop.sh

}

3 standby node keepalived configuration file

[root@ray0redis02 ~] # cat / etc/keepalived/keepalived.conf

! Configuration File for keepalived

Global_defs {

Router_id redis02

}

Vrrp_script chk_redis

{

Script "/ etc/keepalived/scripts/redis_check.sh"

Interval 2

Timeout 2

Fall 3

}

Vrrp_instance redis {

State BACKUP

Interface ens192 # # needs to be modified to the name of the actual network card

Virtual_router_id 60

Priority 90

Advert_int 1

Authentication {# all node must same

Auth_type PASS

Auth_pass 1111

}

Virtual_ipaddress {

10.0.37.226 # need to modify the virtual IP that is actually assigned

}

Track_script {

Chk_redis

}

Notify_master "/ etc/keepalived/scripts/redis_master.sh 127.0.0.1 10.0.37.224 6379" # 10.0.37.224 needs to be modified to the actual remote host IP

Notify_backup "/ etc/keepalived/scripts/redis_backup.sh 127.0.0.1 10.0.37.224 6379" # 10.0.37.224 needs to be modified to the actual remote host IP

Notify_fault / etc/keepalived/scripts/redis_fault.sh

Notify_stop / etc/keepalived/scripts/redis_stop.sh

}

Virtual_server 10.0.37.226 6379 {

Delay_loop 6

Lb_algo rr

Lb_kind NAT

Nat_mask 255.255.255.0

Persistence_timeout 50

Protocol TCP

Sorry_server 127.0.0.1 80

Real_server 10.0.37.224 6379 {

Weight 1

TCP_CHECK {

Connect_timeout 3

Nb_get_retry 3

Delay_before_retry 3

Connect_port 6379

}

Real_server 10.0.37.225 6379 {

Weight 1

TCP_CHECK {

Connect_timeout 3

Nb_get_retry 3

Delay_before_retry 3

Connect_port 6379

}

4 all scripts for two nodes

[root@ray0redis01 ~] # cat / etc/keepalived/scripts/redis_check.sh

#! / bin/bash

ALIVE= `/ usr/local/redis/bin/redis-cli-a 123456 PING`

["$ALIVE" = = "PONG"] & & {echo $ALIVE & & exit 0;} | {echo $ALIVE & & exit 1;}

[root@ray0redis01 ~] # cat / etc/keepalived/scripts/redis_master.sh

#! / bin/bash

REDISCLI= "/ usr/local/redis/bin/redis-cli-h $1-p $3"

LOGFILE= "/ var/log/keepalived-redis-state.log"

Echo "[master]" > > $LOGFILE

Date > > $LOGFILE

Echo "Being master...." > > $LOGFILE

Echo "Run MASTER cmd..." > > $LOGFILE

$REDISCLI SLAVEOF $2 $3 > $LOGFILE

Sleep 10 # delay 10 s wait data async cancel sync

Echo "Run SLAVEOF NO ONE cmd..." > > $LOGFILE

${REDISCLI} SLAVEOF NO ONE > > $LOGFILE

[root@ray0redis01 ~] # cat / etc/keepalived/scripts/redis_backup.sh

#! / bin/bash

REDISCLI= "/ usr/local/redis/bin/redis-cli-h $1-p $3"

LOGFILE= "/ var/log/keepalived-redis-state.log"

Echo "[backup]" > > $LOGFILE

Date > > $LOGFILE

Echo "Run SLAVEOF cmd..." > > $LOGFILE

$REDISCLI SLAVEOF $2 $3 > > $LOGFILE 2 > & 1

Sleep 15 # delay 15 s wait data sync exchange role

[root@ray0redis01 ~] # cat / etc/keepalived/scripts/redis_fault.sh

#! / bin/bash

LOGFILE=/var/log/keepalived-redis-state.log

Echo-e "[fault]\ t $(date'+% F% T')" > > $LOGFILE

[root@ray0redis01 ~] # cat / etc/keepalived/scripts/redis_stop.sh

#! / bin/bash

LOGFILE=/var/log/keepalived-redis-state.log

Start keepalived, verify the condition of HA and switch

[root@ray0redis01 ~] # systemctl status keepalived

● keepalived.service-LVS and VRRP High Availability Monitor

Loaded: loaded (/ usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)

Active: active (running) since Mon 2018-12-03 20:41:42 EST; 1h 10min ago

Process: 5122 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)

Main PID: 5124 (keepalived)

CGroup: / system.slice/keepalived.service

├─ 5124 / usr/sbin/keepalived-D

├─ 5125 / usr/sbin/keepalived-D

└─ 5126 / usr/sbin/keepalived-D

Dec 03 20:57:08 ray0redis01 Keepalived_vrrp [5126]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 03 20:57:08 ray0redis01 Keepalived_vrrp [5126]: Opening script file / etc/keepalived/scripts/redis_master.sh

Dec 03 20:57:13 ray0redis01 Keepalived_vrrp [5126]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 03 20:57:13 ray0redis01 Keepalived_vrrp [5126]: VRRP_Instance (redis) Sending/queueing gratuitous ARPs on ens192 for 10.0.37.226

Dec 03 20:57:13 ray0redis01 Keepalived_vrrp [5126]: Sending gratuitous ARP on ens192 for 10.0.37.226

[root@ray0redis01 ~] # / usr/local/redis/bin/redis-cli info | egrep-A11 Replication

# Replication

Role:master

Connected_slaves:1

Slave0:ip=10.0.37.225,port=6379,state=online,offset=4928,lag=1

Master_replid:ac8db2b7075f51c318b978be0a350b7fd987ddbb

Master_replid2:3e93b153857adbdfa981a3f66fd18244b9bfae5c

Master_repl_offset:4928

Second_repl_offset:183

Repl_backlog_active:1

Repl_backlog_size:1048576

Repl_backlog_first_byte_offset:183

Repl_backlog_histlen:4746

# Kill the redis process

[root@ray0redis01] # kill-9 6605

[root@ray0redis01 ~] # systemctl status keepalived

● keepalived.service-LVS and VRRP High Availability Monitor

Loaded: loaded (/ usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)

Active: active (running) since Mon 2018-12-03 20:41:42 EST; 1h 12min ago

Process: 5122 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)

Main PID: 5124 (keepalived)

CGroup: / system.slice/keepalived.service

├─ 5124 / usr/sbin/keepalived-D

├─ 5125 / usr/sbin/keepalived-D

└─ 5126 / usr/sbin/keepalived-D

Dec 03 20:57:08 ray0redis01 Keepalived_vrrp [5126]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 03 20:57:08 ray0redis01 Keepalived_vrrp [5126]: Opening script file / etc/keepalived/scripts/redis_master.sh

Dec 03 20:57:13 ray0redis01 Keepalived_vrrp [5126]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 03 20:57:13 ray0redis01 Keepalived_vrrp [5126]: VRRP_Instance (redis) Sending/queueing gratuitous ARPs on ens192 for 10.0.37.226

Dec 03 20:57:13 ray0redis01 Keepalived_vrrp [5126]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 03 21:54:33 ray0redis01 Keepalived_vrrp [5126]: / etc/keepalived/scripts/redis_check.sh exited with status 1

Dec 03 21:54:34 ray0redis01 Keepalived_healthcheckers [5125]: TCP connection to [10.0.37.224]: 6379 failed.

# observe the status of the slave node and complete the switch

[root@ray0redis02 ~] # systemctl status keepalived

● keepalived.service-LVS and VRRP High Availability Monitor

Loaded: loaded (/ usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)

Active: active (running) since Mon 2018-12-03 20:54:37 EST; 1h 0min ago

Process: 6112 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)

Main PID: 6114 (keepalived)

CGroup: / system.slice/keepalived.service

├─ 6114 / usr/sbin/keepalived-D

├─ 6115 / usr/sbin/keepalived-D

└─ 6116 / usr/sbin/keepalived-D

Dec 03 21:54:39 ray0redis02 Keepalived_vrrp [6116]: Opening script file / etc/keepalived/scripts/redis_master.sh

Dec 03 21:54:41 ray0redis02 Keepalived_healthcheckers [6115]: TCP connection to [10.0.37.224]: 6379 failed.

Dec 03 21:54:41 ray0redis02 Keepalived_healthcheckers [6115]: Check on service [10.0.37.224]: 6379 failed after 1 retry.

Dec 03 21:54:41 ray0redis02 Keepalived_healthcheckers [6115]: Removing service [10.0.37.224]: 6379 from VS [10.0.37.226]: 6379

Dec 03 21:54:44 ray0redis02 Keepalived_vrrp [6116]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 03 21:54:44 ray0redis02 Keepalived_vrrp [6116]: VRRP_Instance (redis) Sending/queueing gratuitous ARPs on ens192 for 10.0.37.226

Dec 03 21:54:44 ray0redis02 Keepalived_vrrp [6116]: Sending gratuitous ARP on ens192 for 10.0.37.226

[root@ray0redis02] # tail-20f / var/log/messages

Dec 3 21:54:38 localhost Keepalived_healthcheckers [6115]: TCP connection to [10.0.37.224]: 6379 failed.

Dec 3 21:54:38 localhost Keepalived_vrrp [6116]: VRRP_Instance (redis) Transition to MASTER STATE

Dec 3 21:54:39 localhost Keepalived_vrrp [6116]: VRRP_Instance (redis) Entering MASTER STATE

Dec 3 21:54:39 localhost Keepalived_vrrp [6116]: VRRP_Instance (redis) setting protocol VIPs.

Dec 3 21:54:39 localhost Keepalived_vrrp [6116]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 3 21:54:39 localhost Keepalived_vrrp [6116]: VRRP_Instance (redis) Sending/queueing gratuitous ARPs on ens192 for 10.0.37.226

Dec 3 21:54:39 localhost Keepalived_vrrp [6116]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 3 21:54:39 localhost NetworkManager: [1543892079.9698] policy: set-hostname: current hostname was changed outside NetworkManager: 'ray0redis02'

Dec 3 21:54:41 localhost Keepalived_healthcheckers [6115]: TCP connection to [10.0.37.224]: 6379 failed.

Dec 3 21:54:41 localhost Keepalived_healthcheckers [6115]: Check on service [10.0.37.224]: 6379 failed after 1 retry.

Dec 3 21:54:41 localhost Keepalived_healthcheckers [6115]: Removing service [10.0.37.224]: 6379 from VS [10.0.37.226]: 6379

Dec 3 21:54:44 localhost Keepalived_vrrp [6116]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 3 21:54:44 localhost Keepalived_vrrp [6116]: VRRP_Instance (redis) Sending/queueing gratuitous ARPs on ens192 for 10.0.37.226

Dec 3 21:54:44 localhost Keepalived_vrrp [6116]: Sending gratuitous ARP on ens192 for 10.0.37.226

# start the master node, and switch keepalived and redis back to the master node

[root@ray0redis01] # / usr/local/redis/bin/redis-server / usr/local/redis/etc/redis.conf

12049:C 03 Dec 21:56:37.698 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo

12049:C 03 Dec 21:56:37.698 # Redis version=4.0.9, bits=64, commit=00000000, modified=0, pid=12049, just started

12049:C 03 Dec 21:56:37.698 # Configuration loaded

[root@ray0redis01 ~] # systemctl status keepalived

● keepalived.service-LVS and VRRP High Availability Monitor

Loaded: loaded (/ usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)

Active: active (running) since Mon 2018-12-03 20:41:42 EST; 1h 14min ago

Process: 5122 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)

Main PID: 5124 (keepalived)

CGroup: / system.slice/keepalived.service

├─ 5124 / usr/sbin/keepalived-D

├─ 5125 / usr/sbin/keepalived-D

├─ 5126 / usr/sbin/keepalived-D

├─ 12057 / usr/sbin/keepalived-D

├─ 12058 / bin/bash / etc/keepalived/scripts/redis_backup.sh 127.0.0.1 10.0.37.225 6379

└─ 12061 sleep 15

Dec 03 21:56:26 ray0redis01 Keepalived_vrrp [5126]: / etc/keepalived/scripts/redis_check.sh exited with status 1

Dec 03 21:56:28 ray0redis01 Keepalived_vrrp [5126]: / etc/keepalived/scripts/redis_check.sh exited with status 1

Dec 03 21:56:30 ray0redis01 Keepalived_vrrp [5126]: / etc/keepalived/scripts/redis_check.sh exited with status 1

Dec 03 21:56:32 ray0redis01 Keepalived_vrrp [5126]: / etc/keepalived/scripts/redis_check.sh exited with status 1

Dec 03 21:56:34 ray0redis01 Keepalived_vrrp [5126]: / etc/keepalived/scripts/redis_check.sh exited with status 1

Dec 03 21:56:36 ray0redis01 Keepalived_vrrp [5126]: / etc/keepalived/scripts/redis_check.sh exited with status 1

Dec 03 21:56:38 ray0redis01 Keepalived_vrrp [5126]: VRRP_Script (chk_redis) succeeded

Dec 03 21:56:38 ray0redis01 Keepalived_vrrp [5126]: VRRP_Instance (redis) Entering BACKUP STATE

Dec 03 21:56:38 ray0redis01 Keepalived_vrrp [5126]: Opening script file / etc/keepalived/scripts/redis_backup.sh

Dec 03 21:56:39 ray0redis01 Keepalived_vrrp [5126]: VRRP_Instance (redis) forcing a new MASTER election

[root@ray0redis01 ~] #

[root@ray0redis01 ~] # systemctl status keepalived

● keepalived.service-LVS and VRRP High Availability Monitor

Loaded: loaded (/ usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)

Active: active (running) since Mon 2018-12-03 20:41:42 EST; 1h 15min ago

Process: 5122 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)

Main PID: 5124 (keepalived)

CGroup: / system.slice/keepalived.service

├─ 5124 / usr/sbin/keepalived-D

├─ 5125 / usr/sbin/keepalived-D

└─ 5126 / usr/sbin/keepalived-D

Dec 03 21:56:41 ray0redis01 Keepalived_vrrp [5126]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 03 21:56:41 ray0redis01 Keepalived_vrrp [5126]: Opening script file / etc/keepalived/scripts/redis_master.sh

Dec 03 21:56:46 ray0redis01 Keepalived_vrrp [5126]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 03 21:56:46 ray0redis01 Keepalived_vrrp [5126]: VRRP_Instance (redis) Sending/queueing gratuitous ARPs on ens192 for 10.0.37.226

Dec 03 21:56:46 ray0redis01 Keepalived_vrrp [5126]: Sending gratuitous ARP on ens192 for 10.0.37.226

[root@ray0redis01] # tail-f / var/log/keepalived-redis-state.log

Mon Dec 3 21:56:38 EST 2018

Run SLAVEOF cmd...

[master]

Mon Dec 3 21:56:41 EST 2018

Being master....

Run MASTER cmd...

OK Already connected to specified master

Run SLAVEOF NO ONE cmd...

[root@ray0redis02 ~] # systemctl status keepalived

● keepalived.service-LVS and VRRP High Availability Monitor

Loaded: loaded (/ usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)

Active: active (running) since Mon 2018-12-03 20:54:37 EST; 1h 2min ago

Process: 6112 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)

Main PID: 6114 (keepalived)

CGroup: / system.slice/keepalived.service

├─ 6114 / usr/sbin/keepalived-D

├─ 6115 / usr/sbin/keepalived-D

└─ 6116 / usr/sbin/keepalived-D

Dec 03 21:54:44 ray0redis02 Keepalived_vrrp [6116]: Sending gratuitous ARP on ens192 for 10.0.37.226

Dec 03 21:56:38 ray0redis02 Keepalived_healthcheckers [6115]: TCP connection to [10.0.37.224]: 6379 success.

Dec 03 21:56:38 ray0redis02 Keepalived_healthcheckers [6115]: Adding service [10.0.37.224]: 6379 to VS [10.0.37.226]: 6379

Dec 03 21:56:39 ray0redis02 Keepalived_vrrp [6116]: VRRP_Instance (redis) Received advert with higher priority 100, ours 90

Dec 03 21:56:39 ray0redis02 Keepalived_vrrp [6116]: VRRP_Instance (redis) Entering BACKUP STATE

Dec 03 21:56:39 ray0redis02 Keepalived_vrrp [6116]: VRRP_Instance (redis) removing protocol VIPs.

Dec 03 21:56:39 ray0redis02 Keepalived_vrrp [6116]: Opening script file / etc/keepalived/scripts/redis_backup.sh