tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Sumedh Sakdeo <sumedhsak...@gmail.com>
Subject Re: Apache Server failover and session replication
Date Thu, 03 Sep 2009 12:57:31 GMT
Can anyone help in these regards?
Thanks in advance,
Sumedh

On Thu, Sep 3, 2009 at 8:52 AM, Sumedh Sakdeo <sumedhsakdeo@gmail.com>wrote:

> http://tomcat.apache.org/tomcat-6.0-doc/cluster-howto.html
> *How it Works
> *
>
>    1. TomcatA starts up
>    2. TomcatB starts up (Wait that TomcatA start is complete)
>    3. TomcatA receives a request, a session S1 is created.
>    4. TomcatA crashes
>    5. TomcatB receives a request for session S1
>    6. TomcatA starts up
>    7. TomcatA receives a request, invalidate is called on the session (S1)
>    8. TomcatB receives a request, for a new session (S2)
>    9. TomcatA The session S2 expires due to inactivity.
>
> section describes the steps.7-9 steps confusing.
> Does tomcat 6 even support such scenario?
>
> --Sumedh
>
>
>
> On Thu, Sep 3, 2009 at 6:29 AM, Shaun Senecal <ssenecal.work@gmail.com>wrote:
>
>> After re-reading your initial post, the problems might not be as related
>> as
>> I thought since at no point did replication "stop" for me.
>>
>>
>> On Thu, Sep 3, 2009 at 9:56 AM, Shaun Senecal <ssenecal.work@gmail.com
>> >wrote:
>>
>> > We had a similar problem with Tomcat 6 using clustering.  It turns out
>> that
>> > the SSO information is only propagated while all instances are running.
>>  If
>> > Instance-A fails, several users then log in to Instance-B, then
>> Instance-A
>> > comes back up, all of the SSO information for the users that logged in
>> > during the downtime is not included in Instance-A so those users are
>> forced
>> > to re-login once the load balancer sends them to that instance.
>> >
>> > I wrote a fix for it, which might be useful for you.  However, it hasnt
>> > been fully tested and is designed to only share the SSO information at
>> > startup, not all Session information.  If Tomcat doenst handle this
>> case,
>> > then the fix I wrote should be easily extended to handle that.
>>  Basically,
>> > when an instance comes up it broadcasts a request for all known SSO
>> > information to the cluster.  It then takes the first response it gets
>> and
>> > continues processing as normal.
>> >
>> > Let me know if you dont find a proper solution to the problem and I will
>> > try to dig up that fix.  My intention was to post it back to the group,
>> but
>> > I got sidetracked once we (temporarily) stopped using clustering.
>> >
>> >
>> > Shaun
>> >
>> >
>> > On Thu, Sep 3, 2009 at 3:52 AM, Sumedh Sakdeo <sumedhsakdeo@gmail.com
>> >wrote:
>> >
>> >> Hi Rainer,
>> >>
>> >> I am using Tomcat session clustering and Apache Http Server for
>> LB(using
>> >> mod_jk module).  Also, using Tomcat 6. I have made appropriate changes
>> to
>> >> worker.properties and httpd.conf. Also I have made appropriate changes
>> to
>> >> server.xml on each tomcat.
>> >>
>> >> Thanks,
>> >> Sumedh
>> >>
>> >> On Thu, Sep 3, 2009 at 12:15 AM, Rainer Jung <rainer.jung@kippdata.de
>> >> >wrote:
>> >>
>> >> > On 02.09.2009 19:57, Sumedh Sakdeo wrote:
>> >> > > Hello All,
>> >> > >             I have a setup with two tomcat instances(A&B).
I have
>> >> > configured
>> >> > > an apache web server 2.2 for load balancing and fail over. Setup
>> looks
>> >> > fine
>> >> > > as per the configurations suggested. Let tomcat A be handling
some
>> >> > request
>> >> > > at sometime. When tomcat instance(A) goes down, the session is
>> >> replicated
>> >> > to
>> >> > > another tomcat instance(B) successfully. Now tomcat instance B
is
>> >> > handling
>> >> > > those requests. Till this point everything goes fine, but when
I
>> bring
>> >> up
>> >> > > tomcat instance(A) and after that tomcat instance(B) goes down,
the
>> >> > session
>> >> > > is no longer replicated. What might be the issue? In status page
of
>> >> > apache
>> >> > > server I see even if node status is OK session is not replicated
to
>> >> fail
>> >> > > over node for second time.
>> >> >
>> >> > How do you replicate? Are you using Tomcat session clustering? Tomcat
>> >> > 5.5 or Tomcat 6?
>> >> >
>> >> > Regards,
>> >> >
>> >> > Rainer
>> >> >
>> >> > ---------------------------------------------------------------------
>> >> > To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
>> >> > For additional commands, e-mail: users-help@tomcat.apache.org
>> >> >
>> >> >
>> >>
>> >
>> >
>>
>
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message