Either ACL result is inconsistent or http-server-close isn't working

[Gustavo Pinho Oliveira]

Hello,
I'm trying to use HAProxy as a ssl terminator for HTTP and WebSocket.

My problem is that sometimes (randomly it seems) HAProxy selects the wrong
backend and send my ws upgrade request to the http backend.

Below is my haproxy.cfg:

global
        log 127.0.0.1 local0
        chroot /var/lib/haproxy
        tune.ssl.default-dh-param 2048
        user haproxy
        group haproxy
        daemon

defaults
        log     global
        option  dontlognull
        timeout connect 5000ms
        timeout client 50000ms
        timeout server 50000ms

frontend secure_all
        bind 0.0.0.0:443 ssl crt /etc/ssl/domain.pem
        default_backend lighttpd_backend
        acl is_websocket hdr(Upgrade) -i websocket
        acl is_photo_upload path_beg -i /photo_upload

        use_backend websocket_backend if is_websocket
        use_backend photo_upload_backend if is_photo_upload

frontend all
        bind 0.0.0.0:80
        default_backend lighttpd_backend
        acl is_websocket hdr(Upgrade) -i websocket
        acl is_photo_upload path_beg -i /photo_upload

        use_backend websocket_backend if is_websocket
        use_backend photo_upload_backend if is_photo_upload

backend lighttpd_backend
        option http-server-close
        server lighttpd_server 127.0.0.1:8081 maxconn 2048 check

backend websocket_backend
        timeout queue 5000
        timeout server 86400000
        timeout connect 86400000
        server websocket_server 127.0.0.1:8080 maxconn 2048 check

backend photo_upload_backend
        server photo_upload_server 127.0.0.1:8079 maxconn 2048 check

Regards,
Gustavo