优雅搭建redis-cluster

前言

记得年方二八时候，数数还是数得过来的，如今年逾二十八，数都数不清了，前几天在狗东哪里整了《算法导论》、《概率导论》两本教科书看看学学，也好在研究机器学习的时候有解惑的根本。redis-cluster正好成功的引起了我的兴趣，就当着等书之前的休闲折腾

redis早前没有现成的集群模块，如今流行起来了，功能也越来越强大了，下面我就来部署一下，当然这中间也会遇到很多问题的。不过没关系，有问题咱们解决即可

手动部署

根据官网介绍，手动部署集群需要进行一下操作

cd /usr/local/redis
mkdir -p cluster/7000
cp ./etc/redis.conf  cluster/7000
vi cluster/7000/redis.conf

这里我们针对关键的地方修改即可，具体情况如下

port 7000
cluster-enabled yes
cluster-config-file nodes-7000.conf
cluster-node-timeout 5000
appendonly yes

修改完成后，复制

cp -r cluster/7000 cluster/7001
cp -r cluster/7000 cluster/7002
cp -r cluster/7000 cluster/7003
cp -r cluster/7000 cluster/7004
cp -r cluster/7000 cluster/7005

然后依次修改每个节点配置文件的端口号，修改好配置，最后启动所有的节点

redis-server cluster/7000/redis.conf
redis-server cluster/7001/redis.conf
redis-server cluster/7002/redis.conf
redis-server cluster/7003/redis.conf
redis-server cluster/7004/redis.conf
redis-server cluster/7005/redis.conf

这个时候虽然所有节点启动了,但是还不能称之为集群。下面我们要使用ruby的辅助工具redis-trib来将所有的节点联系起来,这个工具就是我们的redis安装源文件的src目录下的redis-trib.rb文件，但是这个文件运行需要ruby版redis的驱动

yum install ruby
gem install redis

安装失败，redis依赖的ruby版本必须要大于2.2.0，下面我们来手动安装ruby2.4.2
先清理yum安装的ruby

yum remove ruby

下面通过RVM（Ruby Version Manager）来安装ruby

gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E37D2BAF1CF37B13E2069D6956105BD0E739499BDB
curl -sSL https://get.rvm.io | bash -s stable
rvm install 2.4.2
gem install redis

安装成功后

./src/redis-trib.rb create --replicas 1 127.0.0.1:7000 127.0.0.1:7001 127.0.0.1:7002 127.0.0.1:7003 127.0.0.1:7004 127.0.0.1:7005

自动部署

以上是手动创建集群的方法，下面还有自动启动节点，创建集群，停止集群的服务，文件在redis安装目录下，为utils/create-cluster/create-cluster

cp utils/create-cluster/create-cluster /etc/init.d/create-cluster
vi /etc/init.d/create-cluster

修改PROT并添加ROOT=/usr/local/redis

#!/bin/bash
# Settings
PORT=6999
TIMEOUT=2000
NODES=6
REPLICAS=1
ROOT=/usr/local/redis
# You may want to put the above config parameters into config.sh in order to
# override the defaults without modifying this script.

if [ -a config.sh ]
then
    source "config.sh"
fi

# Computed vars
ENDPORT=$((PORT+NODES))

if [ "$1" == "start" ]
then
    while [ $((PORT < ENDPORT)) != "0" ]; do
        PORT=$((PORT+1))
        echo "Starting $PORT"
        $ROOT/bin/redis-server --port $PORT --cluster-enabled yes --cluster-config-file nodes-${PORT}.conf --cluster-node-timeout $TIMEOUT --appendonly yes --appendfilename appendonly-${PORT}.aof --dbfilename dump-${PORT}.rdb --logfile ${PORT}.log --daemonize yes
    done
    exit 0
fi

if [ "$1" == "create" ]
then
    HOSTS=""
    while [ $((PORT < ENDPORT)) != "0" ]; do
        PORT=$((PORT+1))
        HOSTS="$HOSTS 127.0.0.1:$PORT"
    done
    $ROOT/src/redis-trib.rb create --replicas $REPLICAS $HOSTS
    exit 0
fi

if [ "$1" == "stop" ]
then
    while [ $((PORT < ENDPORT)) != "0" ]; do
        PORT=$((PORT+1))
        echo "Stopping $PORT"
        $ROOT/bin/redis-cli -p $PORT shutdown nosave
    done
    exit 0
fi

if [ "$1" == "watch" ]
then
    PORT=$((PORT+1))
    while [ 1 ]; do
        clear
        date
        $ROOT/bin/redis-cli -p $PORT cluster nodes | head -30
        sleep 1
    done
    exit 0
fi

if [ "$1" == "tail" ]
then
    INSTANCE=$2
    PORT=$((PORT+INSTANCE))
    tail -f ${PORT}.log
    exit 0
fi

if [ "$1" == "call" ]
then
    while [ $((PORT < ENDPORT)) != "0" ]; do
        PORT=$((PORT+1))
        $ROOT/bin/redis-cli -p $PORT $2 $3 $4 $5 $6 $7 $8 $9
    done
    exit 0
fi

if [ "$1" == "clean" ]
then
    rm -rf *.log
    rm -rf appendonly*.aof
    rm -rf dump*.rdb
    rm -rf nodes*.conf
    exit 0
fi

if [ "$1" == "clean-logs" ]
then
    rm -rf *.log
    exit 0
fi

echo "Usage: $0 [start|create|stop|watch|tail|clean]"
echo "start       -- Launch Redis Cluster instances."
echo "create      -- Create a cluster using redis-trib create."
echo "stop        -- Stop Redis Cluster instances."
echo "watch       -- Show CLUSTER NODES output (first 30 lines) of first node."
echo "tail <id>   -- Run tail -f of instance at base port + ID."
echo "clean       -- Remove all instances data, logs, configs."
echo "clean-logs  -- Remove just instances logs."

启动节点，创建集群就可以用一下命令来实现了

service create-cluster start
service create-cluster create

停止集群

service create-cluster stop

还有watch、tail、clean、clean-logs命令，这里就不一一说明了，这个教程就写到这吧