Hi Baptiste Thanks for your replying.
I am using the balance roundrobin algorithm and sticking on src, not the the balance source algorithm. The configuration has been presented in my first mail as below:
>> backend pool >> balance roundrobin. >> stick-table type ip size 200k expire 600s >> stick on src >> server 1 10.128.7.1:80 id 1 cookie srv1 weight 1 maxconn 0 >> slowstart 0s >> server 2 10.128.7.2:80 id 2 cookie srv2 weight 1 maxconn 0 >> slowstart 0s >> Best Regards, Godbach On 2013/5/29 13:35, Baptiste wrote:
Hi Godbach, Before reading HAProxy source code, it worths reading its configuration guide for the options you use. IE, the balance source algorithm would tell you that: "This algorithm is static by default, which means that changing a server's weight on the fly will have no effect, but this can be changed using "hash-type"." Please update your configuration following the recommandation above and let us know your feedback. Baptiste On Wed, May 29, 2013 at 5:22 AM, Godbach <[email protected]> wrote:Hi, all It is expected that new http request will not get response from the server of which weight was changed to 0. It cannot work well with persistence on src but work well without the persistence in lastest snapshot. There are two servers in my backend, and persistence on src ip has been enabled in backend. The configuration in backend as below: backend pool balance roundrobin. stick-table type ip size 200k expire 600s stick on src server 1 10.128.7.1:80 id 1 cookie srv1 weight 1 maxconn 0 slowstart 0s server 2 10.128.7.2:80 id 2 cookie srv2 weight 1 maxconn 0 slowstart 0s During continuous http requset with the same client, the stick table as below: # table: pool, type: ip, size:204800, used:1 0x17d2284: key=172.22.16.250 use=0 exp=599095 server_id=1 Then I set weight of server 1 to 0 use command as below: set weight pool/1 0 And I get the weight of server 1 with command: get weight pool/1 The result is 0 (initial 1) So I think I have set the weight of sever1 to 0 successfully. But the response still comes from server 1 which server 2 is expected. And the stick table keeps the same. I review the code of process_sticking_rules() in session.c. The codes when server is found as below: 1403 ptr = stktable_data_ptr(rule->table.t, ts, STKTABLE_DT_SERVER_ID); 1404 node = eb32_lookup(&px->conf.used_server_id, stktable_data_cast(ptr, server_id)); 1405 if (node) { 1406 struct server *srv; 1407 1408 srv = container_of(node, struct server, conf.id); 1409 if ((srv->state & SRV_RUNNING) || 1410 (px->options & PR_O_PERSIST) || 1411 (s->flags & SN_FORCE_PRST)) { 1412 s->flags |= SN_DIRECT | SN_ASSIGNED; 1413 s->target = &srv->obj_type; 1414 } 1415 } 1416 } 1417 stktable_touch(rule->table.t, ts, 1); Line 1409 used (srv->state & SRV_RUNNING) to check the server status. If I used srv_is_usable() to instead such as below: - if ((srv->state & SRV_RUNNING) || + if (srv_is_usable(srv->state, srv->eweight) || The new request will get response from server 2 once the weight of server 1 is set to 0. But it seems to be just a workaround. Since the manual of haproxy about 'set weight' says that: A typical usage of this command is to disable a server during an update by setting its weight to zero. I am wondering that whether the flag SRV_RUNNING of server should be cleared or not when its weight is set to 0. -- Best Regards, Godbach
-- Best Regards, Godbach
