What if I have a session clustering mechanism which works asynchronously, so if host A fails, then the sessions will be replicated to server B in several seconds, and if the session is sticky and request is moved to B, only request that will come on that second will fail. But if the load balancer is not sticky, it won't work since the sessions are not replicated realtime
On Tue, Nov 24, 2009 at 2:16 PM, Boyle Owen <owen.bo...@six-group.com>wrote: > > > > > > "The downside is that if the desired server is really down, the > request > > will eventually fail." > > > > I wouldn't want this, the reason why I am using a load balancer > is to have high availability, > > not just to balance a load. > > > > How can I overcome this? > > Aren't there any alternatives? > > > What do you imagine can happen? If you want sessions to be sticky then > if a request has session ID that points to server-A, the request *must* > go there. If server-A is unavailable, the request must wait. > > Alternatively, you can allow failover and then the request will go > straight to server-B, but then it has the wrong session cookie. > > Session affinity and failover are mutually exclusive - there is no way > round it. > > > Also what does it mean to be busy? > > Currently I am using my pc to act as a load balancer in front of > powerfull servers and there > > is only one page request, how can it be busy? > > No idea. It's your server.. You posted that stickysession wasn't working > and I posted back a possible explanation and something to try (did you?) > Maybe it's not the problem - try it and see :-) > > Rgds, > Owen Boyle > Disclaimer: Any disclaimer attached to this message may be ignored. > > > > > On Tue, Nov 24, 2009 at 12:27 PM, Boyle Owen > <owen.bo...@six-group.com> wrote: > > > Try adding "nofailover=On" to the Proxy tag, ie > > > <Proxy balancer://ow1 stickysession=JSESSIONID > lbmethod=byrequests > > nofailover=On> > ... > > By default, if the desired balancer member is busy, the > request will be > routed to another one, even if the stickysession doesn't > match (this is > "failover"). To force apache to hold the request until > the server is > free again, you need to switch this off by switching ON > "nofailover" (so > switching OFF "failover" - confusing, eh? :-) > > The downside is that if the desired server is really > down, the request > will eventually fail. > > Rgds, > Owen Boyle > Disclaimer: Any disclaimer attached to this message may > be ignored. > > > > > ________________________________ > > ? ? ? ?From: Onur Agin [mailto:onura...@gmail.com] > ? ? ? ?Sent: Tuesday, November 24, 2009 11:05 AM > ? ? ? ?To: users@httpd.apache.org > ? ? ? ?Subject: [us...@httpd] Load balancer sticky > session problem > > > > ? ? ? ?Hi, > > ? ? ? ?With the configuration below, sticky sessions > won't work... > ? ? ? ?I checked that both servers get the request with > the same > session IDs. > ? ? ? ?Any ideas? > > > ? ? ? ?<VirtualHost *:8001> > ? ? ? ?# Proxy > ? ? ? ?ProxyRequests Off > ? ? ? ?<Proxy *> > ? ? ? ???Order deny,allow > ? ? ? ???Allow from all > ? ? ? ?</Proxy> > ? ? ? ?<Proxy balancer://ow1 stickysession=JSESSIONID > lbmethod=byrequests> > ? ? ? ???BalancerMember http://10.xxx:7101 > ? ? ? ???BalancerMember http://10.xxx:7102 > ? ? ? ?</Proxy> > > ? ? ? ?ProxyPass / balancer://ow1/ > ? ? ? ?</VirtualHost> > > ? ? ? ?<VirtualHost *:8002> > > ? ? ? ?# Proxy > ? ? ? ?ProxyRequests Off > ? ? ? ?<Proxy *> > ? ? ? ???Order deny,allow > ? ? ? ???Allow from all > ? ? ? ?</Proxy> > ? ? ? ?<Proxy balancer://ow2 stickysession=JSESSIONID > lbmethod=byrequests> > ? ? ? ???BalancerMember http://10.xxx:7103 > ? ? ? ???BalancerMember http://10.xxx:7104 > ? ? ? ?</Proxy> > > ? ? ? ?ProxyPass / balancer://ow2/ > ? ? ? ?</VirtualHost> > > > ? ? ? ?Also my request header is: > > ? ? ? ?GET > > /xxx/resources/org.apache.wicket.markup.html.WicketEventReference/wicket > -event.js;jsessionid=76BF17CE24DB39AC8F6B3639BBA5727D > HTTP/1.1 > ? ? ? ?Accept: */* > ? ? ? ?Referer: > > http://10.xxx:8001/xxx/?class=texan.acq.ui.param.MERPARAM > ? ? ? ?Accept-Language: en-us > ? ? ? ?Accept-Encoding: gzip, deflate > ? ? ? ?User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; > Windows NT 5.1; > SV1; .NET CLR 2.0.50727; MS-RTC LM 8; InfoPath.2) > ? ? ? ?Host: 10.xxx:8001 > ? ? ? ?Connection: Keep-Alive > ? ? ? ?Cookie: > JSESSIONID=76BF17CE24DB39AC8F6B3639BBA5727D > > > This message is for the named person's use only. It may > contain confidential, proprietary or legally privileged information. If > you receive this message in error, please notify the sender urgently and > then immediately delete the message and any copies of it from your > system. Please also immediately destroy any hardcopies of the message. > The sender's company reserves the right to monitor all > e-mail communications through their networks. > > > --------------------------------------------------------------------- > The official User-To-User support forum of the Apache > HTTP Server Project. > See <URL:http://httpd.apache.org/userslist.html> for > more info. > To unsubscribe, e-mail: > users-unsubscr...@httpd.apache.org > ? " ? from the digest: > users-digest-unsubscr...@httpd.apache.org > For additional commands, e-mail: > users-h...@httpd.apache.org > > > > > > --------------------------------------------------------------------- > The official User-To-User support forum of the Apache HTTP Server Project. > See <URL:http://httpd.apache.org/userslist.html> for more info. > To unsubscribe, e-mail: users-unsubscr...@httpd.apache.org > " from the digest: users-digest-unsubscr...@httpd.apache.org > For additional commands, e-mail: users-h...@httpd.apache.org > >
