@bantianys

我猜你所有的 nginx 配所有节点的结果是:前几个后端 Server 在抗大部分流量

来源： http://nginx.org/en/docs/http/ngx_http_upstream_module.html
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By default, requests are distributed between the servers using a weighted round-robin balancing method. In the above example, each 7 requests will be distributed as follows: 5 requests go to backend1.example.com and one request to each of the second and third servers. If an error occurs during communication with a server, the request will be passed to the next server, and so on until all of the functioning servers will be tried. If a successful response could not be obtained from any of the servers, the client will receive the result of the communication with the last server.
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翻译：
默认情况下，使用加权循环平衡方法在服务器之间分配请求。在上面的示例中，每 7 个请求将如下分配：5 个请求转到 backend1.example.com 第二个和第三个服务器中的一个请求。如果在与服务器通信期间发生错误，该请求将被传递到下一个服务器，依此类推，直到尝试所有正常运行的服务器为止。如果无法从任何一台服务器获得成功的响应，则客户端将收到与最后一台服务器的通信结果。