Distributed System-Advanced Chapter-CentOS7-redis Cluster Installation

1. Preparation before installation

Before installing the redis cluster, prepare two centOS 7 hosts, the IP address of host A : 192.168.83.136 , the IP address of host B : 192.168.83.137 ; distribute three redis nodes on hosts A and B ; host A 's three-node redis port is 7000 ,7001,7002 ; The port of the three-node redis of host B is: 7003,7004,7005.

2. Create a node

System redis is installed in the /usr/local/ directory.

1. Create the redis_cluster folder

Create the redis_cluster folder under the /usr/local/redis3.2/ folder

 $:mkdir redis_cluster

2. Create a node

$: mkdir 7000 7001 7002   // represent three nodes and their corresponding ports 7000 7001 7002    

3. Create node redis.conf configuration

Create the redis.conf configuration of the corresponding node, named the port number

$:cp /usr/local/redis-3.2/redis.conf  usr/local/redis-3.2/redis_cluster/7000/ 

Rename

$: Mv reids.conf 7000.conf

4. Modify the node redis.conf configuration

daemonize yes                           //redis runs in the background

pidfile /var/run/redis_ 7000 .pid           //pidfile corresponds to 7000, 7002, 7003

port   7000 // Port 7000 , 7002, 7003                                

cluster-enabled yes                       // Open the cluster and remove the comment #  

cluster-config-file nodes_ 7000 .conf       // The configuration file of the cluster is automatically generated for the first time  

cluster-node-timeout 5000                 // The request timeout setting of 5 seconds is enough  

appendonly yes                  //aof log is turned on as needed, it will record a log for each write operation  

Remarks: The red port above is modified to the corresponding node port number , and the node configuration of redis is also completed according to the above operation , and the following configuration is enabled to start

3. Configuration enable configuration redis7000 , redis7001 , redis7002 ,

1. Create a node startup file

Create startup configuration files for three nodes in the /etc/init.d file directory, named redis7000 , redis7001 , and redis7002 .

$: vi /etc/init.d/redis7000

 

2. Start the file configuration project

Redis7000 startup file configuration content:

#!/bin/sh

# chkconfig: 2345 90 10

# description: Start and Stop redis7000

# Simple Redis init.d script conceived to work on Linux systems

# as it does use of the /proc filesystem.

 

REDISPORT=7000

EXEC=/usr/local/redis3.2/src/redis-server

CLIEXEC=/usr/local/redis3.2/src/redis-cli

 

PIDFILE=/var/run/redis_${REDISPORT}.pid

CONF="/usr/local/redis3.2/redis_cluster/7000/${REDISPORT}.conf"

 

case "$1" in

    start)

        if [ -f $PIDFILE ]

        then

                echo "$PIDFILE exists, process is already running or crashed"

        else

                echo "Starting Redis server..."

                $EXEC $CONF

        be

        ;;

    stop)

        if [ ! -f $PIDFILE ]

        then

                echo "$PIDFILE does not exist, process is not running"

        else

                PID=$(cat $PIDFILE)

                echo "Stopping ..."

                $CLIEXEC -p $REDISPORT shutdown

                while [ -x /proc/${PID} ]

                do

                    echo "Waiting for Redis to shutdown ..."

                    sleep 1

                done

                echo "Redis stopped"

        be

        ;;

    *)

        echo "Please use start or stop as first argument"

        ;;

esac

 

Note: Pay attention to modify the red part in the above content

3 , configure the startup

Change permissions

chmod +x /etc/init.d/redis7000

set to start

chkconfig redis7000 on

 

4. Manually start redis

service redis7000 start

service redis7001 start

service redis7002 start

4. Open the firewall

1. Open the firewall:

firewall-cmd --zone=public --add-port=7000/tcp --permanent

firewall-cmd --zone=public --add-port=17000/tcp --permanent

firewall-cmd --zone=public --add-port=7001/tcp --permanent

firewall-cmd --zone=public --add-port=17001/tcp --permanent

firewall-cmd --zone=public --add-port=7002/tcp --permanent

firewall-cmd --zone=public --add-port=17002/tcp --permanent

2. Restart the firewall

systemctl restart firewalld.service

5. Create a cluster

The redis nodes for building the cluster have been prepared before , and then we need to connect these nodes to build the cluster. An official tool is provided: redis-trib.rb(/usr/local/redis-3.2.1/src/redis-trib.rb) You can see that this bird cannot be executed directly by looking at the suffix. It is a program written in ruby , so we also have to install ruby.

install ruby

1. Install ruby

$:yum -y install ruby ruby-devel rubygems rpm-build

2. Install the redis interface

Then use the gem command to install the redis interface     gem is a toolkit of ruby .

$:gem install redis     // Wait for a while, this is a bit slow

3. Create a cluster

Enter the /usr/local/redis3.2/src/ directory and execute the following command

$:./redis-trib.rb  create  --replicas  1  192.168.83.136:7000 192.168.83.136:7001  192.168.83.136:7002 192.168.83.137:7003  192.168.83.137:7004  192.168.83.137:7005

 

Forgot to take a screenshot here

6. Redis cluster operation command

1. Client connection command

Single client connection command, this command must be in the corresponding redis installation directory src

$: ./redis-cli -h 192.168.83.136 -p 7000

Cluster client connection command

$: ./redis-cli c -h 192.168.83.136 -p 7000

 

2. Cluster command

3. Cluster status

cluster info  : print information about the cluster

cluster nodes  : Lists all nodes ( node ) currently known to the cluster, along with information about these nodes.

cluster forget <node_id>  : Remove the node specified by node_id from the cluster. Columns such as:

CLUSTER FORGET 2ae88288b7bb1a13b959de9abf0c29e5aa185d15

cluster meet <ip> <port>  : Add the node specified by ip and port to the cluster and make it a part of the cluster. For example: CLUSTER MEET 192.168.83.137 7004

 

cluster replicate <node_id>  : Set the current node as the slave node of the node specified by node_id .

 

cluster saveconfig  : Save the configuration file of the node to the hard disk.

1. Slot _

cluster addslots <slot> [slot ...]  : Assign one or more slots ( slot ) to the current node.

cluster delslots <slot> [slot ...]  : Removes the assignment of one or more slots to the current node.
cluster flushslots  : Removes all slots assigned to the current node, making the current node a node with no slots assigned.

cluster setslot <slot> node <node_id>  : assign the slot to the node specified by node_id , if the slot is already assigned to

another node, then let the other node delete the slot > before assigning it.

cluster setslot <slot> migrating <node_id>  : Migrate the slot of this node to the node specified by node_id .

cluster setslot <slot> importing <node_id>  : Import slots from the node specified by node_id to this node.

cluster setslot <slot> stable  : Cancel the import ( import ) or migration ( migrate ) of the slot.

2. Key

cluster keyslot <key>  : In which slot the computed key key should be placed.

cluster countkeysinslot <slot>  : Returns the number of key-value pairs currently contained in the slot .

 

cluster getkeysinslot <slot> <count>  : returns the keys in count slots