apache 2.2 stickysession not working

Question

I configured apache 2.2 httpd.conf as follows:

ProxyPass /xxx balancer://xxx/ stickysession=JSESSIONID|jsessionid nofailover=on
ProxyPassReverse /xxx balancer://xxx/

<Proxy balancer://xxx>
 BalancerMember ajp://localhost:8009/xxx route=www1
        BalancerMember ajp://anotherserver:8009/xxx route=www2
...
</Proxy>

but sticky session is not working. am I missing anything?