ubuntu - 是否有任何 HAProxy 负载平衡算法仅将连接路由到一台服务器？

Question

我在它们前面有三台服务器(MariaDB 服务)和一台 HAProxy 服务器，HAProxy 使用循环分配与这些服务器的连接。但我希望 HAProxy 服务器必须将所有连接路由到 server1。如果 server1 不可达，它必须路由到 server2 .. 是否有任何负载平衡算法使它成为可能？

Answer 1

您可能正在寻找故障转移/备份配置，请在此处查看更多详细信息 (https://www.haproxy.com/blog/failover-and-worst-case-management-with-haproxy/)，这是一个基本示例:

backend mysql
    mode tcp
    balance leastconn
    server s1 10.0.0.1:3306 check 
    server s2 10.0.0.2:3306 check backup
    server s3 10.0.0.3:3306 check backup

来自 HAProxy docs :

backup

When "backup" is present on a server line, the server is onlyused in load balancing when all other non-backup servers areunavailable. Requests coming with a persistence cookie referencing theserver will always be served though. By default, only the firstoperational backup server is used, unless the "allbackups" option isset in the backend. See also the "no-backup" and "allbackups" options.

如果您的服务器属于 galera 集群，您可以尝试 httpwsrep :

backend mysql
    mode tcp
    option httpchk
    default-server check port 9200
    server s1 10.0.0.1:3306 
    server s2 10.0.0.2:3306
    server s3 10.0.0.3:3306