Hi, all Here is the partial of the haproxy.cfg
backend receivers mode http balance roundrobin server s0 172.16.0.202:7700 check maxconn 180 server s1 172.16.0.202:7711 check maxconn 180 I add an option maxconn after keyword server. When haproxy face high volume of requests (about 20000 concurrent requests), it return many 503 page: 503 Service Unavailable No server is available to handle this request. Above message is sent by haproxy ( I found this message in ./src/proto_http.c) . why did haproxy send 503 page? I also did not understand the meaning of optioin maxconn. If I remove this option, haproxy will return only very few 503 page. Do option maxconn in above configration mean: if concurrent requests come from frontend is bigger than 180, haproxy will reject these requests and return 503? If the concurrent requests come from frontend is bigger than 180, will haproxy put these requests into a queue? If yes, can I configure the size of the queue? *Additional info* [jj@p2p3 tmp]$ echo "show errors" | sudo socat stdio /tmp/haproxysock Total events captured on [01/Jul/2014:18:49:29.713] : 0 *Full configuration (haproxy-1.5-dev24)* global log 127.0.0.1 local0 err ulimit-n 500000 maxconn 240000 nbproc 1 stats socket /tmp/haproxysock defaults log global option log-separate-errors mode http option httplog option dontlognull retries 3 option redispatch contimeout 3000 clitimeout 50000 srvtimeout 50000 stats uri /haproxy stats enable frontend http_frontend maxconn 240000 bind *:80 mode http option forceclose option forwardfor reqrep ^([^\ :]*)\ /(.*) \1\ /receiver/\2 reqadd X-Forwarded-Proto:\ http default_backend receivers backend receivers mode http balance roundrobin server s0 172.16.0.202:7700 check maxconn 180 server s1 172.16.0.202:7711 check maxconn 180 server s2 172.16.0.202:7722 check maxconn 180 server s3 172.16.0.202:7733 check maxconn 180 server s4 172.16.0.202:7744 check maxconn 180 server s5 172.16.0.202:7755 check maxconn 180 谢谢 金杰 (Jie Jin)
