混合使用命名服务器和默认服务器时，Nginxstream量将会错误升级

我有nginx的下面的configuration文件。 问题是所有的stream量都会进入上游的clustera。 如何将nginxconfiguration为仅将example.com的stream量发送到clustera，其余的则发送到clusterb？

user www-data; worker_processes 1; error_log /var/log/nginx/error.log; pid /var/run/nginx.pid; events { worker_connections 1024; } http { include /etc/nginx/mime.types; log_format cache '\n*** $remote_addr [$time_local] ' '[$upstream_cache_status] $upstream_response_time ' '$host "$request" ($status) $body_bytes_sent ' '"$http_referer" "$http_user_agent" ' 'Cache-Control: $upstream_http_cache_control ' 'Expires: $upstream_http_expires ' ; access_log /var/log/nginx/access.log cache; sendfile on; keepalive_timeout 65; gzip on; gzip_vary on; gzip_comp_level 6; gzip_proxied any; gzip_disable "MSIE [1-6]\.(?!.*SV1)"; gzip_buffers 16 8k; include /etc/nginx/conf.d/*.conf; proxy_cache_key "$scheme$host$request_uri"; proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=main:10m max_size=1g inactive=30m; upstream clustera { ip_hash; server a.example.com:80; } upstream clusterb { ip_hash; server b.example.com:80; } client_max_body_size 20m; client_body_buffer_size 128k; proxy_connect_timeout 300; proxy_send_timeout 300; proxy_read_timeout 300; # host for example.com should send traffic to clustera server { listen 80; server_name example.com; location ~*(png|jpeg|jpg|gif|ico|css|js)$ { proxy_pass http://clustera; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_cache main; proxy_cache_valid 200 5m; proxy_cache_valid 302 1m; } location / { proxy_pass http://clustera; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; } } # host for everyone else. traffic goes to clusterb server { listen 80; server_name _; if ( $http_user_agent ~* (spider|crawler|slurp) ) { return 503; } set $slow 0; if ( $http_user_agent ~* (bot) ) { set $slow 1; } if ( $slow ) { set $limit_rate 1k; } location ~*(png|jpeg|jpg|gif|ico|css|js)$ { proxy_pass http://clusterb; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_cache main; proxy_cache_valid 200 5m; proxy_cache_valid 302 1m; } location /images { proxy_pass http://clisterb; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; proxy_cache main; proxy_cache_valid 200 5m; proxy_cache_valid 302 1m; } location / { proxy_pass http://clusterb; proxy_set_header Host $host; proxy_set_header X-Real-IP $remote_addr; proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; } } }