Session in-memory replication problem

Question

Hi,
          I am running into some cluster HttpSession replication problems. Here is
          the scenario where replication fails (all servers mentioned here are a
          part of a cluster).
          1a - 2 Weblogic servers (A&B) are running - no users logged in,
          2a - user logs in and a new session in server A is created.
          3a - after several interactions, server A is killed.
          4a - after user makes susequent request, Weblogic correctly fails over
          to server B
          Problem: Not entire session data is replicated. The authentication info
          seems to
          be replicated correctly but there are some collections in the session of
          server A
          that did not make it to the session in server B.
          The interesting part is this: If there is only one server A running to
          begin with and a user
          interacts with it for a while and only then server B is started, when
          after server B starts up
          server A dies - the entire session (which is exactly the same as in the
          failing scenario) is
          corretly replicated in B, including collections that were missing in the
          failing scenario.
          How can this be possible ????
          Thanks for any info on this one - it really puzzles me.
          Andrew
          

Answer 1

Yes, you are on the right track. Everytime you modify the object you should call
          putValue. We will make it more clear in the docs.
          - Prasad
          Andrzej Porebski wrote:
          > Everything is Serilizable. I get no exceptions. I did however read some old
          > posts regarding
          > session replication and I hope I found an answer. It basically seems to boil
          > down to what
          > triggers session sync-up between servers. In my case , I store an object into
          > session and
          > later on manipulate that object directly wihotu session involvment and the
          > results of those manipulations
          > are not replicated - no wonder if HttpSession's putValue method is the only
          > trigger.
          > Am i on the right track here?
          >
          > -Andrew
          >
          > Prasad Peddada wrote:
          >
          > > Do you have non serializable data by any chance?
          > >
          > > - Prasad
          > >
          > > Andrzej Porebski wrote:
          > >
          > > > Hi,
          > > > I am running into some cluster HttpSession replication problems. Here is
          > > > the scenario where replication fails (all servers mentioned here are a
          > > > part of a cluster).
          > > > 1a - 2 Weblogic servers (A&B) are running - no users logged in,
          > > > 2a - user logs in and a new session in server A is created.
          > > > 3a - after several interactions, server A is killed.
          > > > 4a - after user makes susequent request, Weblogic correctly fails over
          > > > to server B
          > > >
          > > > Problem: Not entire session data is replicated. The authentication info
          > > > seems to
          > > > be replicated correctly but there are some collections in the session of
          > > > server A
          > > > that did not make it to the session in server B.
          > > >
          > > > The interesting part is this: If there is only one server A running to
          > > > begin with and a user
          > > > interacts with it for a while and only then server B is started, when
          > > > after server B starts up
          > > > server A dies - the entire session (which is exactly the same as in the
          > > > failing scenario) is
          > > > corretly replicated in B, including collections that were missing in the
          > > > failing scenario.
          > > >
          > > > How can this be possible ????
          > > >
          > > > Thanks for any info on this one - it really puzzles me.
          > > >
          > > > Andrew
          > >
          > > --
          > > Cheers
          > >
          > > - Prasad
          >
          > --
          > -------------------------------------------------------------
          > Andrzej Porebski
          > Sailfish Systems, Ltd. Phone 1 + [phone]
          > 44 Wall Street, 17th floor Fax: 1 + [phone]
          > New York, NY 10005
          > -------------------------------------------------------------