Redis安装及主从配置

Redis是一种面向ldquo;键/值rdquo;对类型数据的分布式NoSQL数据库系统，特点是高性能，持久存储，适应高并发的应用场景。它起步

Redis是一种面向“键/值”对类型数据的分布式NoSQL数据库系统，特点是高性能，持久存储，适应高并发的应用场景。它起步较晚，发展迅速，目前已被许多大型机构采用，如google、taobao、sina微博等。本文不对其数据结构做深入的讲解，只是介绍其安装及主从结构的配置过程。如需要更详细的了解请参考其官方网站。 Redis的安装

Redis目前只支持Linux及BSD等系统，不支持Window下的安装。在Linux下安装的过程如下所示：

$ wget

$ tar xzf redis-2.2.12.tar.gz

$ cd redis-2.2.12

$ make

安装成功后的提示为：

Hint: To run 'make test' is a good idea ;)

make[1]: Leaving directory `/usr/alibaba/install/redis-2.2.12/src'

在安装完成后，即可进入至该工程的src下启动服务：

$ src/redis-server

通过内置的build-cli工具进行相应的测试，其测试过程如下：

$ src/redis-cli

redis> set foo bar

OK

redis> get foo

"bar"

redis > getset foo 123

“bar”

redis >get foo

123

主从结构的配置所涉及到的机器及各机器所完成的功能如下所示：

IP地址                                      

角色

10.20.150.205

主结点

10.20.150.208

从结点1

10.20.150.209

从结点2

在进行主从结构配置之前，请确保已经在上述三台机器上已经安装了Redis服务。对于Redis的主从结构的配置相对比较简单，只需修改redis.conf文件，配置上主结点对应的IP及端口。具体如下所示：

Port 6380

bind 10.20.150.205

slaveof 10.20.150.205 6379

l  port 6380表示当前该Redis服务对应的端口号；

l  bind 10.20.150.205 表示当前Redis绑定的主结点的IP地址；

l  slaveof 10.20.150.205 6379 表示当前Redis是哪个主结点的从结点，其中包括IP及端口号。

当只有一台主结点在启动时，会显示如下的信息：

[29028] 26 Sep 18:39:12 * Server started, Redis version 2.2.12

[29028] 26 Sep 18:39:12 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.

[29028] 26 Sep 18:39:12 * DB loaded from disk: 0 seconds

[29028] 26 Sep 18:39:12 * The server is now ready to accept connections on port 6379

[29028] 26 Sep 18:39:12 - 0 clients connected (0 slaves), 790584 bytes in use

其中主结点会自动检测到有新的从结点启动并加入进来，其显示的信息如下：

[29028] 26 Sep 18:40:31 - Accepted 10.20.150.208:44779

[29028] 26 Sep 18:40:31 * Slave ask for synchronization

[29028] 26 Sep 18:40:31 * Starting BGSAVE for SYNC

[29028] 26 Sep 18:40:31 * Background saving started by pid 29091

[29091] 26 Sep 18:40:31 * DB saved on disk

[29028] 26 Sep 18:40:31 * Background saving terminated with success

[29028] 26 Sep 18:40:31 * Synchronization with slave succeeded

[29028] 26 Sep 18:40:32 - 0 clients connected (1 slaves), 798752 bytes in use

[29028] 26 Sep 18:40:37 - 0 clients connected (1 slaves), 798752 bytes in use

[29028] 26 Sep 18:40:42 - 0 clients connected (1 slaves), 798752 bytes in use

[29028] 26 Sep 18:40:47 - 0 clients connected (1 slaves), 798752 bytes in use

对于从结点显示的信息如下：

#[597] 26 Sep 18:40:29 * Server started, Redis version 2.2.12

[597] 26 Sep 18:40:29 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.

[597] 26 Sep 18:40:29 * The server is now ready to accept connections on port 6379

[597] 26 Sep 18:40:29 - 0 clients connected (0 slaves), 790616 bytes in use

[597] 26 Sep 18:40:29 * Connecting to MASTER...

[597] 26 Sep 18:40:29 * MASTER SLAVE sync started: SYNC sent

[597] 26 Sep 18:40:29 * MASTER SLAVE sync: receiving 10 bytes from master

[597] 26 Sep 18:40:29 * MASTER SLAVE sync: Loading DB in memory

[597] 26 Sep 18:40:29 * MASTER SLAVE sync: Finished with success

[597] 26 Sep 18:40:34 - 1 clients connected (0 slaves), 798744 bytes in use

当有另一台从机挂载至主机时，主机显示的信息如下：