Behaviour of staic variables in clustered environment.

Question

HI,
          I have a class "XYZ" with a static variable "number".
          This holds some information vital to the application.
          Say there are two weblogic servers in a cluster.
          Now what will happen if a server(say server1) in a cluster goes down.
          Will the other server(say server2) which takes up the work of server1 ,
          have the same value for the static variable "number" of class "XYZ" ??
          Regards
          Suchak Jani
          

Answer 1

FWIW ... only thing to remember is that if two servers bind the same name at
          the same time, they will both see their binding (meaning that each one will
          not see the other's binding). Best way to work around is to bind a
          semaphore (e.g. use the server's bind address as a JNDI name) and then scan
          for others (using a timeout) to make sure that only one server binds.
          Cameron Purdy
          Tangosol, Inc.
          http://www.tangosol.com
          +1.617.623.5782
          WebLogic Consulting Available
          "suchak jani" <[email protected]> wrote in message
          news:[email protected]...
          > Hi Cameron
          >
          > As Always , Great to hear from you !
          > Congratulations on winning the Award !
          > May God Bless You !
          >
          > Yes i guess i will try JNDI binding .
          > If the application dies it is not a problem
          > if the information is lost.
          >
          > Thank you so much.
          >
          > Regards
          > Suchak Jani
          >
          >
          >
          > Cameron Purdy wrote:
          >
          > > No. Statics are scoped by the instance of Class that represents their
          > > storage, and thus by class loader, so you are not even guaranteed that
          there
          > > will be only one instance of that static variable on one of those two
          > > Weblogic servers.
          > >
          > > > I have a class "XYZ" with a static variable "number".
          > > > This holds some information vital to the application.
          > >
          > > I believe you need to look for different options for holding information
          > > that is vital to the application. For example, entity EJBs were
          designed to
          > > maintain such information.
          > >
          > > Failover (in Weblogic) only applies to HttpSessions. (In 6.0, it also
          > > applies to stateful session EJBs.) Failover does not imply a single
          > > synchronization point, which is what it sounds like you want. If the
          data
          > > is non-transactional, you may be able to use a Weblogic workspace or
          JNDI
          > > binding to share the data across the cluster, however, I know the JNDI
          > > information is lost on server death and I am not sure about workspaces.
          > >
          > > Peace,
          > >
          > > --
          > > Cameron Purdy
          > > Tangosol, Inc.
          > > http://www.tangosol.com
          > > +1.617.623.5782
          > > WebLogic Consulting Available
          > >
          > > "suchak jani" <[email protected]> wrote in message
          > > news:[email protected]...
          > > > HI,
          > > >
          > > > I have a class "XYZ" with a static variable "number".
          > > > This holds some information vital to the application.
          > > >
          > > > Say there are two weblogic servers in a cluster.
          > > >
          > > > Now what will happen if a server(say server1) in a cluster goes down.
          > > >
          > > > Will the other server(say server2) which takes up the work of server1
          > > > have the same value for the static variable "number" of class "XYZ" ??
          > > >
          > > > Regards
          > > > Suchak Jani
          > > >
          > > >
          >