guozi058 / balancer

Trafficserver plugin : The balancer balances requests across multiple origin servers.

balancer

具体用法：请参考https://docs.trafficserver.apache.org/en/latest/reference/plugins/balancer.en.html

在roundrobin 模式下新增 backup、weight、max_fails、fail_timeout ,以及add path和开启https回源的功能：

####backup=number marks the server as a backup server. It will be passed requests when the primary servers are unavailable.by default, 0 --(0/1)

####weight=number sets the weight of the server, by default, 1.

####max_fails=number sets the number of unsuccessful attempts to communicate with the server that should happen in the duration set by the fail_timeout parameter to consider the server unavailable for a duration also set by the fail_timeout parameter. By default, the number of unsuccessful attempts is set to 3. The zero value disables the accounting of attempts. What is considered an unsuccessful attempt is defined by the proxy_next_upstream, fastcgi_next_upstream, uwsgi_next_upstream, scgi_next_upstream, and memcached_next_upstream directives.

####fail_timeout=time sets the time during which the specified number of unsuccessful attempts to communicate with the server should happen to consider the server unavailable; and the period of time the server will be considered unavailable. By default, the parameter is set to 10 seconds.

#For example: map http://foo.com http://foo.com @plugin=balancer.so @pparam=--policy=roundrobin @pparam=--https @pparam=one.bar.com:80,0,1,3,10 @pparam=two.bar.com,0,1,3,10

#Add path: map http://foo.com http://foo.com @plugin=balancer.so @pparam=--policy=roundrobin,0/ @pparam=one.bar.com:80,0,1,3,10 @pparam=two.bar.com,0,1,3,10
if client request http://cdnxxx.com/1.jpg then ATS will back to the source server request http://cdnxxx.com/0/1.jpg