Nginx从入门到实践：场景实践篇- 负载均衡调度器SLB

朴灿烈づ我的快乐病毒、 2023-06-18 10:00 119阅读 0赞

**1.为什么需要负载均衡**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FuZHk3MTA2NjA1NDE_size_16_color_FFFFFF_t_70][]

减轻单点服务器压力，提高系统可用性与并发量

**2.全局负载均衡**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FuZHk3MTA2NjA1NDE_size_16_color_FFFFFF_t_70 1][]

1.   非全局负载均衡SLB，服务节点和调用节点在一个区域 ，Nginx就是一个非全局负载均衡

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FuZHk3MTA2NjA1NDE_size_16_color_FFFFFF_t_70 2][]

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4层负载均衡在数据链路层，完成包转发就可以了， 7层负载均衡在应用层，可以处理更多信息，Nginx是一个典型的7层负载均衡的SLB

**5.实现原理**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FuZHk3MTA2NjA1NDE_size_16_color_FFFFFF_t_70 5][]

将服务放到upsteam server组中，通过proxy\_pass模块实现对三个服务的不断轮询

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FuZHk3MTA2NjA1NDE_size_16_color_FFFFFF_t_70 6][]

需要注意 upsteam必须配置在server层以外

实战

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FuZHk3MTA2NjA1NDE_size_16_color_FFFFFF_t_70 7][]

三个服务节点分别是 8001，8002，8003，在location中将所有的请求都 proxy\_pass到 [http://imooc][http_imooc],当请求 jeson.t.imooc 时，会通过轮询转发到 8001，8002，8003

实战举例

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FuZHk3MTA2NjA1NDE_size_16_color_FFFFFF_t_70 8][]

upstream 后面跟的是我们自定义的虚拟服务的名字，里面对应的是每一个server，支持IP和域名，也可以加端口，同时也支持socket，backup表示这是一个备份节点，weight 表示轮询的权重，

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FuZHk3MTA2NjA1NDE_size_16_color_FFFFFF_t_70 9][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0FuZHk3MTA2NjA1NDE_size_16_color_FFFFFF_t_70 10][]

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[http_imooc]: http://imooc/
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