Is there a way to have haproxy send a per-server argument during a health-check? Right now, I do "server A check addr localhost 9000" and "server B check addr localhost 9001" and so on, and have xinetd monitor 9000/TCP and 9001/TCP. When haproxy connects to those, xinetd in turn runs a health-check script I wrote that actually does the checking. When done checking the script returns either HTTP200 or HTTP500 depending on if it's good or not.
This means I start using one port per back-end server. If I have 10 server that haproxy spreads the load across, I have "server ... 9002" and "server ... 9003" and so on through 9009. I then have 10 different copies of my little script, each of which just connects to a different server (A, B, C...) and does the check. If haproxy could do something like "server A check addr localhost 9000 argument A", I could have only one port watched by xinetd, and only one copy of the script, that would simply accept "A" as an argument of the server it should check. I use option httpchk with the above (all in the same "listen" group). But I wasn't sure if I could change option httpchk for every server. Could I do a: listen farm address:port balance roundrobin mode tcp option httpchk GET 1 server A 1.1.1.1:389 check addr localhost port 9000 inter 5s fastinter 1s downinter 120s option httpchk GET 2 server B 1.1.1.2:389 check addr localhost port 9000 inter 5s fastinter 1s downinter 120s Would that do a "GET 1" when it tries a http health check for server A and do a "GET 2" when doing a health check for server B? These are LDAP servers on the back-end, btw. I can't put the health-check script on the back-end server itself. And they wanted to make sure the health-check passed from the actual haproxy load-balancer talking to the back-end server, rather than the back-end server talking to itself. Thank you, PH
