Shulou(Shulou.com)06/01 Report--

Principle

Cluster technology is the main technology for building highly concurrent websites. The greatest pressure to visit a website is to query the database when visiting a page and respond accordingly. Redis has supported the cluster function since version 3.0. to make the cluster work properly, there must be at least three master nodes.

Redis clustering is based on the concept of hash slot (hash slot). Redis only integrates 16384 slots. When placing a KYE in redis, redis will calculate a value for this KEY using crc16 algorithm, and then surplus this value to 16383, so that each KEY will correspond to a number between 0 and 16383, and redis will allocate hash slots to different nodes according to the number of nodes.

When you want to take the value of a certain KEY, redis will calculate a value through the KYE name you want to get, calculate a value through crc16, and then make a remainder with 16383, find the corresponding node through the remainder, and then find the key value on this node.

Redis continues the feature of read-write separation. Each master node has a slave node, and a slave node can also have a slave node.

The master node is responsible for writing and the slave node is responsible for reading data in memory.

Node and Node listen to each other. Once Node exits, the other Node will automatically share the slot of Node.

Their own slot will not be reassigned, which does not affect the use of other slot

Environment

Three machines A machine can open multiple redis with multiple ports

192.168.123.160:6379192.168.123.160:6380192.168.123.170:6379192.168.123.170:6380192.168.123.180:6379192.168.123.180:6380

The redis cluster tool is included in the Redis installation package

Installation packages required for cluster tools

Zlib-1.2.8.tar.gz http://nchc.dl.sourceforge.net/project/libpng/zlib/1.2.8/zlib-1.2.8.tar.gz

Ruby-2.2.9.tar.gz https://cache.ruby-lang.org/pub/ruby/2.2/ruby-2.2.9.tar.gz

Rubygems-2.5.1.tgz https://rubygems.global.ssl.fastly.net/rubygems/rubygems-2.5.1.tgz

Redis-3.2.2.gem https://rubygems.global.ssl.fastly.net/gems/redis-3.2.2.gem

Redis-3.2.3.tar.gz http://download.redis.io/releases/redis-3.2.3.tar.gz

Configuration

Install zlib

Gunzip zlib-1.2.8.tar.gztar-xvf zlib-1.2.8.tarcd zlib-1.2.8./configuremakemake install

Install ruby

Because the version of yum installation is lower, the higher version of redis cluster is not supported, so we use the high version of

Tar-zxvf ruby-2.2.9.tar.gzcd ruby-2.2.4./configure-prefix=/usr/local/rubymakemaek install cp ruby / bin

Install rubygems

Tar-zxvf rubygems-2.5.1.tgzcd rubygems-2.5.1ruby setup.rbcp bin/gem / bin

Install gem-redis

Gem install-l redis-3.2.2.gem

Redis (all 3 servers need to be installed)

Tar-zxvf redis-3.2.3.tar.gzcd redis-3.2.3make

Configuration file for redis

Redis.conf needs to be modified.

Bind 0.0.0.0 # address that the redis service listens to. If the test is changed to a local address, the port 6379 # startup port will be better. If it is a redis-6380.conf configuration file, change it to 6380daemonize yes # change it to yes, and let redis run pidfile / var/run/redis_6379.pid # in the background. If it is a redis-6380.conf configuration file, Modify the bit redis_6380.pidlogfile / usr/local/redis/logs/redis-6379.log # if it is a redis-6380.conf configuration file, change it to redis_6380.pidcluster-enabled yes # enable the cluster cluster-config-file nodes-51-6379.conf # if it is a redis-6380.conf configuration file, change it to nodes-51-6380.conf

Redis cluster

Copy the tool cp src/redis-server / usr/local/redis/cp src/redis-cli / usr/local/rediscp src/redis-trib.rb / usr/local/redis in the source package

Start redis and create a cluster

Redis-server redis.conf # needs to be started on each machine. Multiple configuration files redis-trib.rb create-replicas 1 192.168.123.160 redis-trib.rb create 6379 192.168.123.160 redis-trib.rb create 6380 192.168.123.170 redis-trib.rb create 6380 192.168.123.180 redis-trib.rb create 6379 192.168.123.180 redis-trib.rb create 6380 # create clusters

Then type yes.

View cluster nodes

Redis-trib.rb check 192.168.123.160:6379

The above information appears, indicating that the cluster has been installed successfully

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