Redis服务之Redis Cluster
redis cluster 把所有的 redis node 映射到 0-16383 个槽位(slot)上，读写需要到指定的 redis node 上进行操作，因此有多少个 reids node 相当于 redis 并发扩展了多少倍。Redis cluster 预先分配 16384 个(slot)槽位，当需要在 redis 集群中写入一个 key -value 的时候，会使用 CRC16(key) mod 16384 之后的值，决定将 key 写入值哪一个槽位从而决定写入哪一个 Redis 节点上，从而有效解决redis单机读写瓶颈。
在上一篇博客中我们聊到了redis的高可用组件sentinel的相关配置，回顾请参考https://www.cnblogs.com/qiuhom-1874/p/13429776.html；sentinel在redis主从同步架构中主要起到了监控集群master是否正常，如果master不正常，或者宕机，那么sentinel会提升一个slave当选新的master，从而保证了redis服务的正常使用；但对于redis的单机写入问题还是一直存在；在sentinel+主从同步架构中，程序写数据，始终是把读写请求发送给master（当然，如果有语句路由器读写请求是可以分开的）；这样一来对于master来讲它就承担了所有的写操作，很显然这种在写操作非常的频繁的场景，单台master肯定无法承受这么大的压力；为了解决单机master写入数据的瓶颈问题， redis 官方在 redis 3.0 版本之后推出了无中心架构的 redis cluster 机制；所谓无中心架构的cluster意思是集群中的每一个成员都是中心节点，每个成员拥有整个集群的状态元数据，但各自又只存储整个集群的部分数据；对于redis cluster这种架构来讲，所有redis节点使用（ping机制）互联，如果集群中某个节点的失败，是需要整个集群中超过半数的节点监测都失效才算真正的失效；客户端不需要 proxy 即可直接连接 redis，应用程序需要写全部的 redis 服务器 IP。redis cluster 把所有的 redis node 映射到 0-16383 个槽位(slot)上，读写需要到指定的 redis node 上进行操作，因此有多少个 reids node 相当于 redis 并发扩展了多少倍。Redis cluster 预先分配 16384 个(slot)槽位，当需要在 redis 集群中写入一个 key -value 的时候，会使用 CRC16(key) mod 16384 之后的值，决定将 key 写入值哪一个槽位从而决定写入哪一个 Redis 节点上，从而有效解决redis单机读写瓶颈。如下所示
提示：客户端每次读写都要经过CRC16对读写的KEY做hash计算，然后把hash后的结果再和16384做取模运算，最终结果会落到0-16383的某一个槽位上；我们事先在定义集群时，就把0-5460号槽位都分给了master01，意思就是只要读写的数据的KEY通过CRC16hash计算取得的结果%16384，最后的结果在0-5460这个范围内，就把本次的读/写请求调度到master01上；以此类推，范围在5461-10922就把读/写请求调度到master02,范围在10923-16383就把读/写请求调度到master03;通过上面的图我们也能看出各个master都只保存整个集群的一部分数据，如果某一个master宕机，那么就会导致对应master上分的槽位对应数据丢失；为了解决各个master单点的问题，我们还需要对每个master做主从，如下图
提示：为了防止某个master宕机后导致数据丢失和写操作不能执行，对应slave应该能够及时的提升为master，类似sentinel的功能，但是我们不需要在部署sentinel了，因为redis cluster就支持主从切换；这样一来我们的集群就变成了3主3从的集群；接下我们就准备一个实验环境来部署上面的架构；
部署redis集群
环境说明
| 角色 | ip地址 | 端口 |
| Master01 | 192.168.0.41 | 6379 |
| Slave01 | 192.168.0.42 | 6380 |
| Master02 | 192.168.0.42 | 6379 |
| Slave02 | 192.168.0.43 | 6380 |
| Master03 | 192.168.0.43 | 6379 |
| Slave03 | 192.168.0.41 | 6380 |
准备启动3台服务器，每个服务器上启动两个redis实例，端口分别是6379（master）和6380（slave)，为了防止master和slave落在同一个节点，有意将他们交叉组合，如上表格；
创建redis cluster我们需要注意每个 redis node 节点尽量采用相同的硬件配置，相同的密码；所有 redis 服务器必须没有任何数据；
在node01上编译安装redis，有关redis的编译安装和部署请参考https://www.cnblogs.com/qiuhom-1874/p/13378138.html；
创建目录结构
[root@node01 ~]# tree /usr/local/redis/
/usr/local/redis/
├── 6379
│ ├── etc
│ │ ├── redis.conf
│ │ └── sentinel.conf
│ ├── logs
│ └── run
├── 6380
│ ├── etc
│ │ ├── redis.conf
│ │ └── sentinel.conf
│ ├── logs
│ └── run
└── bin
├── redis-benchmark
├── redis-check-aof
├── redis-check-rdb
├── redis-cli
├── redis-sentinel -> redis-server
└── redis-server
9 directories, 10 files
[root@node01 ~]#
提示：在/usr/local/redis目录下分别创建6379和6380,然后在其下都创建etc,logs,run 等子目录，如上所示
修改配置文件
[root@node01 ~]# grep -E "^(bind|requirepass|masterauth|cluster)" /usr/local/redis/6379/etc/redis.conf bind 0.0.0.0 masterauth admin requirepass admin cluster-enabled yes cluster-config-file redis-cluster_6379.conf [root@node01 ~]# grep -E "^(bind|requirepass|masterauth|cluster)" /usr/local/redis/6380/etc/redis.conf bind 0.0.0.0 masterauth admin requirepass admin cluster-enabled yes cluster-config-file redis-cluster_6380.conf [root@node01 ~]#
提示：6379和6380的配置文件内容都是一样的，唯一区别是端口不同，主要修改bind 监听地址，设置密码，开启集群以及指定对应集群生成的配置文件名称；
把node01上的/usr/local/redis复制给node02和node03并保存到/usr/local/目录下
提示：我上面的三台主机都是做了免密登录，所以互相拷贝数据不需要输入密码；有关免密登录的说明和配置可以参考https://www.cnblogs.com/qiuhom-1874/p/11783371.html；
分别在node01 node02 node03上启动redis
到此我们就把6个redis实例启动了；接下来我们来创建集群；Redis 3 和 4 版本需要使用到集群管理工具 redis-trib.rb，这个工具是 redis 官方推出的管理 redis 集群的工具，集成在redis 的源码 src 目录下，是基于 redis 提供的集群命令封装成简单、便捷、实用的操作工具，redis-trib.rb是 redis 作者用 ruby 开发完成的，所以我们要使用redis-trib.rb首先要解决ruby环境的问题；
安装ruby环境
[root@node01 ~]# rz
rz waiting to receive.
zmodem trl+C ȡ
100% 15621 KB 15621 KB/s 00:00:01 0 Errors
[root@node01 ~]# ls
redis-4.0.9.tar.gz ruby-2.5.5.tar.gz
[root@node01 ~]# tar xf ruby-2.5.5.tar.gz -C /usr/local/src/
[root@node01 ~]# cd /usr/local/src/
[root@node01 src]# cd ruby-2.5.5/
[root@node01 ruby-2.5.5]# ./configure
checking for ruby... false
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking target system type... x86_64-pc-linux-gnu
checking for gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables...
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking for g++... g++
checking whether we are using the GNU C++ compiler... yes
……省略部分内容……
checking for setjmp type... __builtin_setjmp
checking for prefix of external symbols... NONE
checking pthread.h usability... yes
checking pthread.h presence... yes
checking for pthread.h... yes
checking if make is GNU make... yes
.ext/include/x86_64-linux/ruby/config.h updated
configure: ruby library version = 2.5.0
configure: creating ./config.status
config.status: creating GNUmakefile
config.status: creating Makefile
config.status: creating ruby-2.5.pc
---
Configuration summary for ruby version 2.5.5
* Installation prefix: /usr/local
* exec prefix: ${prefix}
* arch: x86_64-linux
* site arch: ${arch}
* RUBY_BASE_NAME: ruby
* ruby lib prefix: ${libdir}/${RUBY_BASE_NAME}
* site libraries path: ${rubylibprefix}/${sitearch}
* vendor path: ${rubylibprefix}/vendor_ruby
* target OS: linux
* compiler: gcc
* with pthread: yes
* enable shared libs: no
* dynamic library ext: so
* CFLAGS: ${optflags} ${debugflags} ${warnflags}
* LDFLAGS: -L. -fstack-protector -rdynamic \
-Wl,-export-dynamic
* optflags: -O3
* debugflags: -ggdb3
* warnflags: -Wall -Wextra -Wno-unused-parameter \
-Wno-parentheses -Wno-long-long \
-Wno-missing-field-initializers \
-Wno-tautological-compare \
-Wno-parentheses-equality \
-Wno-constant-logical-operand -Wno-self-assign \
-Wunused-variable -Wimplicit-int -Wpointer-arith \
-Wwrite-strings -Wdeclaration-after-statement \
-Wimplicit-function-declaration \
-Wdeprecated-declarations \
-Wno-packed-bitfield-compat \
-Wsuggest-attribute=noreturn \
-Wsuggest-attribute=format
* strip command: strip -S -x
* install doc: yes
* man page type: doc
---
[root@node01 ruby-2.5.5]#
提示：redis-trib.rb这个工具在集群任意一台安装即可，不需要每台都安装；
编译
[root@node01 ruby-2.5.5]# make -j 2
CC = gcc
LD = ld
LDSHARED = gcc -shared
CFLAGS = -O3 -ggdb3 -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wno-tautological-compare -Wno-parentheses-equality -Wno-constant-logical-operand -Wno-self-assign -Wunused-variable -Wimplicit-int -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration -Wdeprecated-declarations -Wno-packed-bitfield-compat -Wsuggest-attribute=noreturn -Wsuggest-attribute=format -std=gnu99
XCFLAGS = -D_FORTIFY_SOURCE=2 -fstack-protector -fno-strict-overflow -fvisibility=hidden -fexcess-precision=standard -DRUBY_EXPORT -fPIE
CPPFLAGS = -I. -I.ext/include/x86_64-linux -I./include -I. -I./enc/unicode/10.0.0
DLDFLAGS = -fstack-protector -pie
SOLIBS =
LANG = en_US.UTF-8
LC_ALL =
LC_CTYPE =
gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
compiling ./main.c
compiling dmydln.c
compiling miniinit.c
compiling dmyext.c
compiling miniprelude.c
making dummy probes.h
compiling bignum.c
compiling class.c
compiling compar.c
compiling compile.c
compiling complex.c
compiling cont.c
compiling debug.c
compiling debug_counter.c
compiling dir.c
compiling dln_find.c
compiling encoding.c
compiling enum.c
compiling enumerator.c
……省略部分内容……
*** Fix the problems, then remove these directories and try again if you want.
make[1]: Leaving directory `/usr/local/src/ruby-2.5.5'
Generating RDoc documentation
Parsing sources...
100% [871/871] vsnprintf.c
Generating RI format into /usr/local/src/ruby-2.5.5/.ext/rdoc...
Files: 871
Classes: 1324 ( 565 undocumented)
Modules: 286 ( 121 undocumented)
Constants: 2181 ( 555 undocumented)
Attributes: 1066 ( 251 undocumented)
Methods: 10080 (2161 undocumented)
Total: 14937 (3653 undocumented)
75.54% documented
Elapsed: 25.0s
[root@node01 ruby-2.5.5]#
安装ruby环境
[root@node01 ruby-2.5.5]# make install
CC = gcc
LD = ld
LDSHARED = gcc -shared
CFLAGS = -O3 -ggdb3 -Wall -Wextra -Wno-unused-parameter -Wno-parentheses -Wno-long-long -Wno-missing-field-initializers -Wno-tautological-compare -Wno-parentheses-equality -Wno-constant-logical-operand -Wno-self-assign -Wunused-variable -Wimplicit-int -Wpointer-arith -Wwrite-strings -Wdeclaration-after-statement -Wimplicit-function-declaration -Wdeprecated-declarations -Wno-packed-bitfield-compat -Wsuggest-attribute=noreturn -Wsuggest-attribute=format -std=gnu99
XCFLAGS = -D_FORTIFY_SOURCE=2 -fstack-protector -fno-strict-overflow -fvisibility=hidden -fexcess-precision=standard -DRUBY_EXPORT -fPIE
CPPFLAGS = -I. -I.ext/include/x86_64-linux -I./include -I. -I./enc/unicode/10.0.0
DLDFLAGS = -fstack-protector -pie
SOLIBS =
LANG = en_US.UTF-8
LC_ALL =
LC_CTYPE =
gcc (GCC) 4.8.5 20150623 (Red Hat 4.8.5-39)
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
generating enc.mk
making srcs under enc
make[1]: Entering directory `/usr/local/src/ruby-2.5.5'
make[1]: Nothing to be done for `srcs'.
make[1]: Leaving directory `/usr/local/src/ruby-2.5.5'
generating transdb.h
transdb.h unchanged
generating makefiles ext/configure-ext.mk
ext/configure-ext.mk updated
make[1]: Entering directory `/usr/local/src/ruby-2.5.5'
make[1]: Leaving directory `/usr/local/src/ruby-2.5.5'
generating makefile exts.mk
exts.mk updated
make[1]: Entering directory `/usr/local/src/ruby-2.5.5'
make[2]: Entering directory `/usr/local/src/ruby-2.5.5/ext/fcntl'
make[2]: Leaving directory `/usr/local/src/ruby-2.5.5/ext/fcntl'
make[2]: Entering directory `/usr/local/src/ruby-2.5.5/ext/rubyvm'
……省略部分内容……
installing binary commands: /usr/local/bin
installing base libraries: /usr/local/lib
installing arch files: /usr/local/lib/ruby/2.5.0/x86_64-linux
installing pkgconfig data: /usr/local/lib/pkgconfig
installing command scripts: /usr/local/bin
installing library scripts: /usr/local/lib/ruby/2.5.0
installing common headers: /usr/local/include/ruby-2.5.0
installing manpages: /usr/local/share/man/man1
installing extension objects: /usr/local/lib/ruby/2.5.0/x86_64-linux
installing extension objects: /usr/local/lib/ruby/site_ruby/2.5.0/x86_64-linux
installing extension objects: /usr/local/lib/ruby/vendor_ruby/2.5.0/x86_64-linux
installing extension headers: /usr/local/include/ruby-2.5.0/x86_64-linux
installing extension scripts: /usr/local/lib/ruby/2.5.0
installing extension scripts: /usr/local/lib/ruby/site_ruby/2.5.0
installing extension scripts: /usr/local/lib/ruby/vendor_ruby/2.5.0
installing extension headers: /usr/local/include/ruby-2.5.0/ruby
installing default gems from lib: /usr/local/lib/ruby/gems/2.5.0 (build_info, cache, doc, extensions, gems, specifications)
cmath 1.0.0
csv 1.0.0
fileutils 1.0.2
ipaddr 1.2.0
rdoc 6.0.1
scanf 1.0.0
webrick 1.4.2
installing default gems from ext: /usr/local/lib/ruby/gems/2.5.0 (build_info, cache, doc, extensions, gems, specifications)
bigdecimal 1.3.4
date 1.0.0
etc 1.0.0
fcntl 1.0.0
fiddle 1.0.0
io-console 0.4.6
json 2.1.0
psych 3.0.2
sdbm 1.0.0
stringio 0.0.1
strscan 1.0.0
installing bundled gems: /usr/local/lib/ruby/gems/2.5.0 (build_info, cache, doc, extensions, gems, specifications)
minitest 5.10.3
rake 12.3.0
xmlrpc 0.3.0
did_you_mean 1.2.0
net-telnet 0.1.1
power_assert 1.1.1
test-unit 3.2.7
installing rdoc: /usr/local/share/ri/2.5.0/system
installing capi-docs: /usr/local/share/doc/ruby
[root@node01 ruby-2.5.5]#
提示：到此ruby环境就安装好了，这里注意一点，yum安装的ruby版本有点低，所以我们这里选择编译安装；
gem安装redis包
[root@node01 ruby-2.5.5]# gem install redis
ERROR: Loading command: install (LoadError)
cannot load such file -- zlib
ERROR: While executing gem ... (NoMethodError)
undefined method `invoke_with_build_args' for nil:NilClass
[root@node01 ruby-2.5.5]#
提示：gem安装提示我们没有zlib，遇到这个问题我们用yum安装zlib-devel包，然后在把zlib集成到ruby环境即可；
[root@node01 ruby-2.5.5]# yum install zlib-devel Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.aliyun.com * extras: mirrors.aliyun.com * updates: mirrors.aliyun.com Resolving Dependencies --> Running transaction check ---> Package zlib-devel.x86_64 0:1.2.7-18.el7 will be installed --> Processing Dependency: zlib = 1.2.7-18.el7 for package: zlib-devel-1.2.7-18.el7.x86_64 --> Running transaction check ---> Package zlib.x86_64 0:1.2.7-17.el7 will be updated ---> Package zlib.x86_64 0:1.2.7-18.el7 will be an update --> Finished Dependency Resolution Dependencies Resolved =========================================================================================================== Package Arch Version Repository Size =========================================================================================================== Installing: zlib-devel x86_64 1.2.7-18.el7 base 50 k Updating for dependencies: zlib x86_64 1.2.7-18.el7 base 90 k Transaction Summary =========================================================================================================== Install 1 Package Upgrade ( 1 Dependent package) Total download size: 140 k Is this ok [y/d/N]: y Downloading packages: Delta RPMs disabled because /usr/bin/applydeltarpm not installed. (1/2): zlib-devel-1.2.7-18.el7.x86_64.rpm | 50 kB 00:00:00 /2): zlib-1.2.7-18.el7.x86_64.rpm | 90 kB 00:00:00 ----------------------------------------------------------------------------------------------------------- Total 509 kB/s | 140 kB 00:00:00 Running transaction check Running transaction test Transaction test succeeded Running transaction Updating : zlib-1.2.7-18.el7.x86_64 1/3 Installing : zlib-devel-1.2.7-18.el7.x86_64 2/3 Cleanup : zlib-1.2.7-17.el7.x86_64 3/3 Verifying : zlib-devel-1.2.7-18.el7.x86_64 1/3 Verifying : zlib-1.2.7-18.el7.x86_64 2/3 Verifying : zlib-1.2.7-17.el7.x86_64 3/3 Installed: zlib-devel.x86_64 0:1.2.7-18.el7 Dependency Updated: zlib.x86_64 0:1.2.7-18.el7 Complete! [root@node01 ruby-2.5.5]#
集成zlib库到Ruby环境
[root@node01 ruby-2.5.5]# cd ext/zlib/ [root@node01 zlib]# ruby extconf.rb checking for deflateReset() in -lz... yes checking for zlib.h... yes checking for crc32_combine() in zlib.h... yes checking for adler32_combine() in zlib.h... yes checking for z_crc_t in zlib.h... yes creating Makefile [root@node01 zlib]# make make: *** No rule to make target `/include/ruby.h', needed by `zlib.o'. Stop. [root@node01 zlib]#
提示：遇到这种问题，我们需要打开上面生成的Makefile 把zlib.o: $(top_srcdir)/include/ruby.h替换为zlib.o: ../../include/ruby.h即可
提示：修改好Makefile，再次make
"Makefile" 282L, 8468C written [root@node01 zlib]# make compiling zlib.c linking shared-object zlib.so [root@node01 zlib]# make install /usr/bin/install -c -m 0755 zlib.so /usr/local/lib/ruby/site_ruby/2.5.0/x86_64-linux [root@node01 zlib]#
再次使用gem安装redis包
[root@node01 zlib]# gem install redis
ERROR: While executing gem ... (Gem::Exception)
Unable to require openssl, install OpenSSL and rebuild Ruby (preferred) or use non-HTTPS sources
[root@node01 zlib]#
提示：它提示我们缺少openssl库，处理方法安装openssl-devel包，然后把openssl库集成到ruby环境中；
安装openssl-devel包
[root@node01 zlib]# yum install openssl-devel Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: mirrors.aliyun.com * extras: mirrors.aliyun.com * updates: mirrors.aliyun.com Resolving Dependencies --> Running transaction check ---> Package openssl-devel.x86_64 1:1.0.2k-19.el7 will be installed --> Processing Dependency: openssl-libs(x86-64) = 1:1.0.2k-19.el7 for package: 1:openssl-devel-1.0.2k-19.el7.x86_64 --> Processing Dependency: krb5-devel(x86-64) for package: 1:openssl-devel-1.0.2k-19.el7.x86_64 --> Running transaction check ---> Package krb5-devel.x86_64 0:1.15.1-46.el7 will be installed ……省略部分内容…… Installed: openssl-devel.x86_64 1:1.0.2k-19.el7 Dependency Installed: keyutils-libs-devel.x86_64 0:1.5.8-3.el7 krb5-devel.x86_64 0:1.15.1-46.el7 libcom_err-devel.x86_64 0:1.42.9-17.el7 libkadm5.x86_64 0:1.15.1-46.el7 libselinux-devel.x86_64 0:2.5-15.el7 libsepol-devel.x86_64 0:2.5-10.el7 libverto-devel.x86_64 0:0.2.5-4.el7 pcre-devel.x86_64 0:8.32-17.el7 Dependency Updated: e2fsprogs.x86_64 0:1.42.9-17.el7 e2fsprogs-libs.x86_64 0:1.42.9-17.el7 krb5-libs.x86_64 0:1.15.1-46.el7 libcom_err.x86_64 0:1.42.9-17.el7 libselinux.x86_64 0:2.5-15.el7 libselinux-python.x86_64 0:2.5-15.el7 libselinux-utils.x86_64 0:2.5-15.el7 libsepol.x86_64 0:2.5-10.el7 libss.x86_64 0:1.42.9-17.el7 openssl.x86_64 1:1.0.2k-19.el7 openssl-libs.x86_64 1:1.0.2k-19.el7 Complete! [root@node01 zlib]#
集成openssl到ruby环境中
[root@node01 zlib]# cd .. [root@node01 ext]# ls bigdecimal date fcntl json psych ripper Setup.nt -test- cgi dbm fiber nkf pty rubyvm socket win32 configure-ext.mk digest fiddle objspace racc sdbm stringio win32ole continuation etc gdbm openssl rbconfig Setup strscan zlib coverage extmk.rb io pathname readline Setup.atheos syslog [root@node01 ext]# cd openssl/ [root@node01 openssl]# ls depend ossl_asn1.c ossl_digest.c ossl_ocsp.c ossl_pkey_rsa.c ossl_x509ext.c deprecation.rb ossl_asn1.h ossl_digest.h ossl_ocsp.h ossl_rand.c ossl_x509.h extconf.rb ossl_bio.c ossl_engine.c ossl_pkcs12.c ossl_rand.h ossl_x509name.c exts.mk ossl_bio.h ossl_engine.h ossl_pkcs12.h ossl_ssl.c ossl_x509req.c History.md ossl_bn.c ossl.h ossl_pkcs7.c ossl_ssl.h ossl_x509revoked.c lib ossl_bn.h ossl_hmac.c ossl_pkcs7.h ossl_ssl_session.c ossl_x509store.c Makefile ossl.c ossl_hmac.h ossl_pkey.c ossl_version.h ruby_missing.h mkmf.log ossl_cipher.c ossl_kdf.c ossl_pkey_dh.c ossl_x509attr.c openssl.gemspec ossl_cipher.h ossl_kdf.h ossl_pkey_dsa.c ossl_x509.c openssl_missing.c ossl_config.c ossl_ns_spki.c ossl_pkey_ec.c ossl_x509cert.c openssl_missing.h ossl_config.h ossl_ns_spki.h ossl_pkey.h ossl_x509crl.c [root@node01 openssl]# ruby extconf.rb checking for t_open() in -lnsl... no checking for socket() in -lsocket... no checking for openssl/ssl.h... yes checking for OpenSSL version is 1.0.1 or later... yes checking for RAND_egd()... yes ……省略部分内容…… checking for X509_get0_notBefore()... no checking for SSL_SESSION_get_protocol_version()... no checking for EVP_PBE_scrypt()... no creating extconf.h creating Makefile [root@node01 openssl]# make compiling openssl_missing.c make: *** No rule to make target `/include/ruby.h', needed by `ossl.o'. Stop. [root@node01 openssl]#
提示：这个错误和刚才继承zlib库到ruby环境中类似，处理方式同上面的处理方式一样修改Makefile文件，在makefile定义变量的位置增加top_srcdir = ../..
再次make
Makefile" 1458L, 49182C written [root@node01 openssl]# make compiling ossl.c compiling ossl_asn1.c compiling ossl_bio.c compiling ossl_bn.c compiling ossl_cipher.c compiling ossl_config.c compiling ossl_digest.c compiling ossl_engine.c compiling ossl_hmac.c compiling ossl_kdf.c compiling ossl_ns_spki.c compiling ossl_ocsp.c compiling ossl_pkcs12.c compiling ossl_pkcs7.c compiling ossl_pkey.c compiling ossl_pkey_dh.c compiling ossl_pkey_dsa.c compiling ossl_pkey_ec.c compiling ossl_pkey_rsa.c compiling ossl_rand.c compiling ossl_ssl.c compiling ossl_ssl_session.c compiling ossl_x509.c compiling ossl_x509attr.c compiling ossl_x509cert.c compiling ossl_x509crl.c compiling ossl_x509ext.c compiling ossl_x509name.c compiling ossl_x509req.c compiling ossl_x509revoked.c compiling ossl_x509store.c linking shared-object openssl.so [root@node01 openssl]# make install /usr/bin/install -c -m 0755 openssl.so /usr/local/lib/ruby/site_ruby/2.5.0/x86_64-linux installing default openssl libraries [root@node01 openssl]#
再次用gem安装redis包
[root@node01 openssl]# gem install redis Fetching: redis-4.2.1.gem (100%) Successfully installed redis-4.2.1 Parsing documentation for redis-4.2.1 Installing ri documentation for redis-4.2.1 Done installing documentation for redis after 0 seconds 1 gem installed [root@node01 openssl]#
提示：到此ruby环境就准备好了，redis包也安装好了，接下来我们把redis-trib.rb连接到/usr/bin/下，然后执行redis-trib.rb，如果能够正常执行说明ruby环境没有问题，如果不能则还需要调整
软连接redis-trib.rb到/usr/bin/
[root@node01 openssl]# find /usr/local/src/redis-4.0.9/ -name "redis-trib.rb"
/usr/local/src/redis-4.0.9/src/redis-trib.rb
[root@node01 openssl]# ln -s /usr/local/src/redis-4.0.9/src/redis-trib.rb /usr/bin/
[root@node01 openssl]# redis-trib.rb
Usage: redis-trib <command> <options> <arguments ...>
create host1:port1 ... hostN:portN
--replicas <arg>
check host:port
info host:port
fix host:port
--timeout <arg>
reshard host:port
--from <arg>
--to <arg>
--slots <arg>
--yes
--timeout <arg>
--pipeline <arg>
rebalance host:port
--weight <arg>
--auto-weights
--use-empty-masters
--timeout <arg>
--simulate
--pipeline <arg>
--threshold <arg>
add-node new_host:new_port existing_host:existing_port
--slave
--master-id <arg>
del-node host:port node_id
set-timeout host:port milliseconds
call host:port command arg arg .. arg
import host:port
--from <arg>
--copy
--replace
help (show this help)
For check, fix, reshard, del-node, set-timeout you can specify the host and port of any working node in the cluster.
[root@node01 openssl]#
提示：可以看到redis-trib.rb可以正常打印出帮助信息，说明当前ruby环境能够支持redis-trib.rb运行；
添加密码到刚才下载的redis包的库文件中
提示：这里需要把对应密码字符串用引号把它引起来；
创建集群
[root@node01 ~]# redis-trib.rb create --replicas 1 192.168.0.41:6379 192.168.0.42:6379 192.168.0.43:6379 192.168.0.41:6380 192.168.0.42:6380 192.168.0.43:6380 >>> Creating cluster >>> Performing hash slots allocation on 6 nodes... Using 3 masters: 192.168.0.41:6379 192.168.0.42:6379 192.168.0.43:6379 Adding replica 192.168.0.42:6380 to 192.168.0.41:6379 Adding replica 192.168.0.43:6380 to 192.168.0.42:6379 Adding replica 192.168.0.41:6380 to 192.168.0.43:6379 M: 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 192.168.0.41:6379 slots:0-5460 (5461 slots) master M: e99b0b450e78719d63520cb6efc068d5e8d4d081 192.168.0.42:6379 slots:5461-10922 (5462 slots) master M: a7ace08c36f7d55c4f28463d72865aa1ff74829e 192.168.0.43:6379 slots:10923-16383 (5461 slots) master S: 62ece0b80b83c0f1f078b07fc1687bb8376f76b3 192.168.0.41:6380 replicates a7ace08c36f7d55c4f28463d72865aa1ff74829e S: dbfff4c49a94c0ee55d14401ccc9245af3655427 192.168.0.42:6380 replicates 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 S: 91169e71359deed96f8778cf31c823dbd6ded350 192.168.0.43:6380 replicates e99b0b450e78719d63520cb6efc068d5e8d4d081 Can I set the above configuration? (type 'yes' to accept): yes >>> 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 192.168.0.41:6379) M: 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 192.168.0.41:6379 slots:0-5460 (5461 slots) master 1 additional replica(s) S: 91169e71359deed96f8778cf31c823dbd6ded350 192.168.0.43:6380 slots: (0 slots) slave replicates e99b0b450e78719d63520cb6efc068d5e8d4d081 M: e99b0b450e78719d63520cb6efc068d5e8d4d081 192.168.0.42:6379 slots:5461-10922 (5462 slots) master 1 additional replica(s) M: a7ace08c36f7d55c4f28463d72865aa1ff74829e 192.168.0.43:6379 slots:10923-16383 (5461 slots) master 1 additional replica(s) S: dbfff4c49a94c0ee55d14401ccc9245af3655427 192.168.0.42:6380 slots: (0 slots) slave replicates 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 S: 62ece0b80b83c0f1f078b07fc1687bb8376f76b3 192.168.0.41:6380 slots: (0 slots) slave replicates a7ace08c36f7d55c4f28463d72865aa1ff74829e [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. [root@node01 ~]#
提示：从上面的信息可以了解到，我们给指定了6个redis实例的地址和端口，它给我们创建了3个master3个slave，并且在3个master上平均分配了16384个槽位；如果能看到后面的ok all 16384 slots covered,说明集群创建成功；--replicates用来指定集群中每个master的副本数量，1表示每个master有一个副本；
查看集群状态信息
[root@node01 ~]# redis-trib.rb info 192.168.0.41:6379 192.168.0.41:6379 (8c785e6e...) -> 0 keys | 5461 slots | 1 slaves. 192.168.0.42:6379 (e99b0b45...) -> 0 keys | 5462 slots | 1 slaves. 192.168.0.43:6379 (a7ace08c...) -> 0 keys | 5461 slots | 1 slaves. [OK] 0 keys in 3 masters. 0.00 keys per slot on average. [root@node01 ~]# redis-trib.rb check 192.168.0.41:6379 >>> Performing Cluster Check (using node 192.168.0.41:6379) M: 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 192.168.0.41:6379 slots:0-5460 (5461 slots) master 1 additional replica(s) S: 91169e71359deed96f8778cf31c823dbd6ded350 192.168.0.43:6380 slots: (0 slots) slave replicates e99b0b450e78719d63520cb6efc068d5e8d4d081 M: e99b0b450e78719d63520cb6efc068d5e8d4d081 192.168.0.42:6379 slots:5461-10922 (5462 slots) master 1 additional replica(s) M: a7ace08c36f7d55c4f28463d72865aa1ff74829e 192.168.0.43:6379 slots:10923-16383 (5461 slots) master 1 additional replica(s) S: dbfff4c49a94c0ee55d14401ccc9245af3655427 192.168.0.42:6380 slots: (0 slots) slave replicates 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 S: 62ece0b80b83c0f1f078b07fc1687bb8376f76b3 192.168.0.41:6380 slots: (0 slots) slave replicates a7ace08c36f7d55c4f28463d72865aa1ff74829e [OK] All nodes agree about slots configuration. >>> Check for open slots... >>> Check slots coverage... [OK] All 16384 slots covered. [root@node01 ~]#
提示：从上面的信息可以看到192.168.0.41/42/43的6379端口都是master，并且都有一个slave节点；
确认master状态
[root@node01 ~]# redis-cli -h 192.168.0.41 192.168.0.41:6379> AUTH admin OK 192.168.0.41:6379> CLUSTER INFO cluster_state:ok cluster_slots_assigned:16384 cluster_slots_ok:16384 cluster_slots_pfail:0 cluster_slots_fail:0 cluster_known_nodes:6 cluster_size:3 cluster_current_epoch:6 cluster_my_epoch:1 cluster_stats_messages_ping_sent:606 cluster_stats_messages_pong_sent:586 cluster_stats_messages_sent:1192 cluster_stats_messages_ping_received:581 cluster_stats_messages_pong_received:606 cluster_stats_messages_meet_received:5 cluster_stats_messages_received:1192 192.168.0.41:6379> info replication # Replication role:master connected_slaves:1 slave0:ip=192.168.0.42,port=6380,state=online,offset=854,lag=0 master_replid:303943ae1e9f54e3525abda2fd1efff905bf08e3 master_replid2:0000000000000000000000000000000000000000 master_repl_offset:854 second_repl_offset:-1 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:1 repl_backlog_histlen:854 192.168.0.41:6379> quit [root@node01 ~]# redis-cli -h 192.168.0.42 192.168.0.42:6379> auth admin OK 192.168.0.42:6379> info replication # Replication role:master connected_slaves:1 slave0:ip=192.168.0.43,port=6380,state=online,offset=896,lag=0 master_replid:f4e1b75b8f30be622868814fc4618a4584f3aa32 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:896 192.168.0.42:6379> CLUSTER INFO cluster_state:ok cluster_slots_assigned:16384 cluster_slots_ok:16384 cluster_slots_pfail:0 cluster_slots_fail:0 cluster_known_nodes:6 cluster_size:3 cluster_current_epoch:6 cluster_my_epoch:2 cluster_stats_messages_ping_sent:662 cluster_stats_messages_pong_sent:645 cluster_stats_messages_meet_sent:5 cluster_stats_messages_sent:1312 cluster_stats_messages_ping_received:644 cluster_stats_messages_pong_received:667 cluster_stats_messages_meet_received:1 cluster_stats_messages_received:1312 192.168.0.42:6379> quit [root@node01 ~]# redis-cli -h 192.168.0.43 192.168.0.43:6379> AUTH admin OK 192.168.0.43:6379> CLUSTER INFO cluster_state:ok cluster_slots_assigned:16384 cluster_slots_ok:16384 cluster_slots_pfail:0 cluster_slots_fail:0 cluster_known_nodes:6 cluster_size:3 cluster_current_epoch:6 cluster_my_epoch:3 cluster_stats_messages_ping_sent:683 cluster_stats_messages_pong_sent:787 cluster_stats_messages_meet_sent:4 cluster_stats_messages_sent:1474 cluster_stats_messages_ping_received:786 cluster_stats_messages_pong_received:687 cluster_stats_messages_meet_received:1 cluster_stats_messages_received:1474 192.168.0.43:6379> info replication # Replication role:master connected_slaves:1 slave0:ip=192.168.0.41,port=6380,state=online,offset=952,lag=1 master_replid:7cbc7d52452717cd49a0e543f6efdccafe5fe1bd master_replid2:0000000000000000000000000000000000000000 master_repl_offset:952 second_repl_offset:-1 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:1 repl_backlog_histlen:952 192.168.0.43:6379> quit [root@node01 ~]#
提示：可以看到集群状态都是正常ok的，并且41的6379对应42的6380，42的6379对应43的6380，43的6379对应41的6380，刚好master和slave都是错开的；
查看集群各node对应关系
提示：上面的node对应是依据id号来的。到此redis集群就正常的跑起来了；
验证：在master上任意写入一个数据看看会发生什么？
提示：在master01上写入k1，它提示我们到192.168.0.43：6379上去写；这是因为我们写入k1计算的槽位是12706，这个槽位是在master03上，所以在master01上就不能正常的写入；这同时也告诉我们，要使用redis集群，客户端还必须能够智能去理解redis协议，通过集群返回的信息，把对应请求调度到对应master上执行；
验证读请求
提示：从上面的信息可以确定一点，这三个主节点他们互相数据是完全隔离的，也就说master01不知道master02上到底有没有对应的数据，它只知道应该去master02上去查看才知道；这就是我们之前说的，每个节点拥有整个集群的全部状态信息（元数据），而每个节点只拥有部分数据在本节点；
验证：把任意一个master节点宕机，看看对应slave是否能够被提升为master，接管master呢？
提示：可以看到当master01宕机以后，对应slave就被提升为master；
查看master01的配置文件是否有改动？
[root@node01 ~]# cat /usr/local/redis/redis-cluster_6379.conf 91169e71359deed96f8778cf31c823dbd6ded350 192.168.0.43:6380@16380 master - 0 1596648345000 8 connected 5461-10922 dbfff4c49a94c0ee55d14401ccc9245af3655427 192.168.0.42:6380@16380 slave 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 0 1596648345510 9 connected 62ece0b80b83c0f1f078b07fc1687bb8376f76b3 192.168.0.41:6380@16380 slave a7ace08c36f7d55c4f28463d72865aa1ff74829e 0 1596648343893 4 connected e99b0b450e78719d63520cb6efc068d5e8d4d081 192.168.0.42:6379@16379 slave 91169e71359deed96f8778cf31c823dbd6ded350 0 1596648344903 8 connected 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 192.168.0.41:6379@16379 myself,master - 0 1596648345000 9 connected 0-5460 a7ace08c36f7d55c4f28463d72865aa1ff74829e 192.168.0.43:6379@16379 master - 0 1596648345000 3 connected 10923-16383 vars currentEpoch 9 lastVoteEpoch 0 [root@node01 ~]# ps -ef |grep redis root 15980 1 0 Aug05 ? 00:00:17 redis-server 0.0.0.0:6380 [cluster] root 30867 1 0 01:19 ? 00:00:02 redis-server 0.0.0.0:6379 [cluster] root 30949 14690 0 01:30 pts/0 00:00:00 grep --color=auto redis [root@node01 ~]# redis-cli -a admin 127.0.0.1:6379> info replication # Replication role:master connected_slaves:1 slave0:ip=192.168.0.42,port=6380,state=online,offset=4476,lag=0 master_replid:ed690ba2766e6e334ffc298fc6aba8be80465aa8 master_replid2:776b5f996d78171e7c5ab5419d65c6c14a253bda master_repl_offset:4476 second_repl_offset:4071 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:3595 repl_backlog_histlen:882 127.0.0.1:6379> quit [root@node01 ~]# kill -9 30867 [root@node01 ~]# redis-cli -h 192.168.0.42 -p 6380 192.168.0.42:6380> AUTH admin OK 192.168.0.42:6380> info replication # Replication role:master connected_slaves:0 master_replid:d46c0a3761b61352b1fc75986ab3343e04a89b83 master_replid2:ed690ba2766e6e334ffc298fc6aba8be80465aa8 master_repl_offset:4518 second_repl_offset:4519 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:4071 repl_backlog_histlen:448 192.168.0.42:6380> quit [root@node01 ~]# cat /usr/local/redis/redis-cluster_6379.conf 91169e71359deed96f8778cf31c823dbd6ded350 192.168.0.43:6380@16380 master - 0 1596648345000 8 connected 5461-10922 dbfff4c49a94c0ee55d14401ccc9245af3655427 192.168.0.42:6380@16380 slave 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 0 1596648345510 9 connected 62ece0b80b83c0f1f078b07fc1687bb8376f76b3 192.168.0.41:6380@16380 slave a7ace08c36f7d55c4f28463d72865aa1ff74829e 0 1596648343893 4 connected e99b0b450e78719d63520cb6efc068d5e8d4d081 192.168.0.42:6379@16379 slave 91169e71359deed96f8778cf31c823dbd6ded350 0 1596648344903 8 connected 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 192.168.0.41:6379@16379 myself,master - 0 1596648345000 9 connected 0-5460 a7ace08c36f7d55c4f28463d72865aa1ff74829e 192.168.0.43:6379@16379 master - 0 1596648345000 3 connected 10923-16383 vars currentEpoch 9 lastVoteEpoch 0 [root@node01 ~]# grep slaveof /usr/local/redis/6379/etc/redis.conf # Master-Slave replication. Use slaveof to make a Redis instance a copy of # slaveof <masterip> <masterport> [root@node01 ~]#
提示：从上面的信息可以看到，在master01没有宕机前和宕机以后slave被提升为master后，对应的配置信息都没有发生变化；我上面为了验证配置文件是否发生变化，先是把master01上线，然后把对应slave下线在上线，还原master01为master角色；
重新把master上线，看看它的配置文件有什么变化？角色还会是master吗？
[root@node01 ~]# redis-server /usr/local/redis/6379/etc/redis.conf [root@node01 ~]# ss -tnl State Recv-Q Send-Q Local Address:Port Peer Address:Port LISTEN 0 511 *:6379 *:* LISTEN 0 511 *:6380 *:* LISTEN 0 128 *:22 *:* LISTEN 0 100 127.0.0.1:25 *:* LISTEN 0 511 *:16379 *:* LISTEN 0 511 *:16380 *:* LISTEN 0 128 :::22 :::* LISTEN 0 100 ::1:25 :::* [root@node01 ~]# cat /usr/local/redis/redis-cluster_6379.conf 91169e71359deed96f8778cf31c823dbd6ded350 192.168.0.43:6380@16380 master - 1596649311329 1596649311326 8 connected 5461-10922 8c785e6ec3f8f7ff4fb7768765da8b8a93f26855 192.168.0.41:6379@16379 myself,slave dbfff4c49a94c0ee55d14401ccc9245af3655427 0 1596649311326 9 connected e99b0b450e78719d63520cb6efc068d5e8d4d081 192.168.0.42:6379@16379 slave 91169e71359deed96f8778cf31c823dbd6ded350 0 1596649311331 8 connected a7ace08c36f7d55c4f28463d72865aa1ff74829e 192.168.0.43:6379@16379 master - 0 1596649311332 3 connected 10923-16383 62ece0b80b83c0f1f078b07fc1687bb8376f76b3 192.168.0.41:6380@16380 slave a7ace08c36f7d55c4f28463d72865aa1ff74829e 0 1596649311331 4 connected dbfff4c49a94c0ee55d14401ccc9245af3655427 192.168.0.42:6380@16380 master - 0 1596649311332 10 connected 0-5460 vars currentEpoch 10 lastVoteEpoch 0 [root@node01 ~]# redis-cli 127.0.0.1:6379> AUTH admin OK 127.0.0.1:6379> info replication # Replication role:slave master_host:192.168.0.42 master_port:6380 master_link_status:up master_last_io_seconds_ago:5 master_sync_in_progress:0 slave_repl_offset:4686 slave_priority:100 slave_read_only:1 connected_slaves:0 master_replid:d46c0a3761b61352b1fc75986ab3343e04a89b83 master_replid2:0000000000000000000000000000000000000000 master_repl_offset:4686 second_repl_offset:-1 repl_backlog_active:1 repl_backlog_size:1048576 repl_backlog_first_byte_offset:4519 repl_backlog_histlen:168 127.0.0.1:6379>
提示：可以看到，重新把master01上线以后，它自动降级为slave了，并且配置文件也从master需改成slave了；这应该是redis cluster在检测到192.168.0.41：6379上线后，触发把内存中的配置同步到对应文件，使得对应配置文件也被修改了；到此一个redis cluster 就搭建测试完成了；
作者：Linux-1874
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