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Web tier: servlets, JSP, Web frameworks: Info about clustering

  1. Info about clustering (3 messages)

    Hi,
    I have a servlet which authenticates the user while he is logging in.If another person logs in with the same name , the first user will be displayed a message saying that the same user has logged on in another machine with the same login(The same scenario as in Yahoo messenger and AOL chat).

    For this to achieve I am using HTTPSession to know the username who all have logged on

    If I use clusters for load balancing and failover, whether my info in HTTPSession will be validated(replicated) for all the servers in the cluster so that any point of time only one user with the same username can log on.

    Its urgent

    Thanx in advance

    Threaded Messages (3)

  2. Info about clustering[ Go to top ]

    If you are using clustering than depending
    on internal implementation :
    a) the session object will be replicated across all the server (or set of servers)
    or
    b) automatically the users request for a session
    will be routed (pinned) to the same server
    which created it.. (eg weblogic does this plus
    having another server having the backup of
    session information
    )





    If you want to prevent another user from using
    the same user name/password than you need to
    maintain the "users Login status" in the
    database and prevent another new user to
    login to the site based on the login status..

    Thanks,
    Zahid
  3. Info about clustering[ Go to top ]

    Hi Zaheed,

    Thanks for your suggestion

    I have a doubt.

    If we are storing the login status in the database, what if the user closes the browser without logging out.
    He cannot login again.So how can this problem be solved

    Do reply
  4. Info about clustering[ Go to top ]

    Normally you should log out the user after
    certain period of inactivity.. This can
    be done by storing last accessed time in
    the Session and have background thread to
    clean up session/database information..

    Normally most of the web site allow two
    logins to occur... But if you intend to
    have only one user to login at a time
    (and only the recently logged in user) than
    you may store the session id of latest logged
    in user in the database... This id will prevent
    first login from hitting the server ...