设置：
2 or more nginx machines
each machine has the same virtual hosts
traffic is load balanced via DNS to each machine
我需要弄清楚什么是最好的工具来获取一些流量统计数据，最感兴趣的是点击量和以千兆字节为单位的总流量。显然，日志信息会来自 nginx，格式如下：
log_format main '$remote_addr $host $remote_user [$time_local] "$request" '
'$status $body_bytes_sent "$http_referer" "$http_user_agent" "$gzip_ratio"';