Hi,
according to http://haproxy.1wt.eu/knownbugs-1.3.html
the bug "(M) appsession lookup in URL does not work" is true up to 1.3.14.2.
I'm currently testing the "appsession" feature with 1.3.22, 1.3.24 and 1.4.4.
Only 1.4.4 seems to work the way the documentation suggests, using the
following test config:
global
log /dev/log daemon debug
pidfile /var/run/haproxy.pid
maxconn 8192
user haproxy
group haproxy
defaults
log global
retries 3
option redispatch
maxconn 8192
frontend my-frontend x.x.x.x:80
mode http
log /dev/log daemon info
option httplog
option dontlognull
option httpclose
default_backend my-backend
backend my-backend
mode http
option httpclose
#balance roundrobin
#balance url_param JSESSIONID check_post
#cookie JSESSIONID prefix
appsession JSESSIONID len 10 timeout 3h request-learn mode query-string
server s01 x.x.x.10:80 cookie AAAAAA check inter 5000 weight 22
server s02 x.x.x.20:80 cookie BBBBBB check inter 5000 weight 22
("mode query-string" only used with 1.4.4, "cookie xxxx" are remains from the
"cookie" parameter)
My test script is setting a cookie. I call it with
http://test/cookie.php?JSESSIONID=xxxxx
Dumping the hash table with 1.4.4 shows a "get_srv_from_appsession" for the
appsession in the get
string and a "manage_server_side_cookies" for the cookie from the server (at
least that's what I guess).
With 1.3.22 and .24 I just get the "manage_server_side_cookies". When I
constantly deny the cookie,
the requests are round robbed, while with 1.4.4 they are sticky from the first
request on, because
the url appsession lookup in the url is working.
Will this be fixed in 1.3.x or do you suggest to upgrade to 1.4?
I know about the drawbacks of appsession, i.e. in memory hash lost on reload or
failover. Will there
be some kind of hash table dump and failover to another system?
Why am I even thinking about using appsession? I'm testing appsession because
this seems to be the
best way to overcome stickiness problems which might occur with "cookie" +
"balance url_param" (see
commented out part in the config) on the very first request of a new user.
Maybe there's an option
to this?
The problem I'm seeing: With "cookie" + "balance url_param" the very first
request will be round
robbed, if both cookie and url_param are not present. So if a user has cookies
disabled, after the
first request, the user will click on a link, which includes his session ID as
a parameter. So with
"balance url_param" the value of the session ID will be hashed and the user
might end up on a
different server, hence information created locally on the system of the first
request will be
unavailable. Further requests will be directed to the same system. I know, in a
cluster user related
data should be kept redundant, but in this case this is not an option.
Best regards,
Michael
