Please help, HAProxy keeps switching between servers

user41094 · 06-23-2014, 03:03 PM

I'm building an application in PHP + MySQL Database that allows college students to register an account and build up their university schedule for the current semester.
- In page 1, students fill in their personal information
- In page 2, they choose the classes they want to sign-up for
- In page 3, they can see what their schedule will look like based on the classes they chose

I have a HAProxy that balances the requests using roundrobin algorithm to one of my two webservers.
E.g: When client1 connects to my application, his request will be sent to webserver1.
Afterwards, client2 connects to my application, his request will be sent to webserver2.
And so on..

My problem is the way that my HAProxy is switching between webservers, is messing with my users sessions.
Take this for example:
- Client1 connects to application. HAproxy sends his request to Webserver1
- Client1 fills in information, and clicks next
- HAProxy sends request to webserver 2 instead of 1!
And since all the information was passed in webserver 1, webserver 2 won't display any of it!

My question is:
If a client connects to webserver 1, how can I make it so HAProxy forces that client to stay always in webserver 1?
And vice-versa for webserver 2.

This is my HAProxy config file:

Code:

global
	log 127.0.0.1 local0
	log 127.0.0.1 local0 notice
	maxconn 2000
	user haproxy
	group haproxy
	daemon

defaults
	log global
	mode http
	option httplog
	option dontlognull
	retries 3
	option redispatch
	timeout connect 5000
	timeout client 10000
	timeout server 1000


listen haproxy001 192.168.1.100:80
	mode http
	stats enable
	stats uri /haproxy?stats
	stats realm Strictly\ Private
	stats auth admin:admin
	cookie JSESSIONID prefix
	balance roundrobin
	option httpclose
	option forwardfor
	option httpchk HEAD / HTTP/1.0
	server server1 192.168.1.93:80 cookie A weight 50 check
	server server2 192.168.1.94:80 cookie B weight 50 check

dijetlo · 06-24-2014, 06:20 AM

Quote:

And since all the information was passed in webserver 1, webserver 2 won't display any of it!

If the pages were being populated from a centralized database, then it wouldn't really matter which webserver you were reaching, the page information would be pulled from the database based on the users index entry.
If you're counting on stored information on the web server to populate the pages, on the other hand, you'd have to point the "next" page to a one that can only be reached on the same webserver they started the process on.

Server A
Index -->next=nexta
Server B
Index -->next=nextb

Though I'd go with the database solution, for ease of maintenance if for no other reason.