Clustering with Cisco LD

Question

The on-line documents regarding clustering talks about using a single
          web server front-end with the WLS plug-in and the plug-in sending the
          WLS request to multiple WLSs in a cluster.
          The environment that Im dealing with involves a Cisco LD load balancing
          for two Netscape Servers .... and the two hosts where Netscape Servers
          are loaded are also loaded with the NES plug-in and with WLS 5.1. ( Why
          WLS is
          not on a different host is another matter ... mostly cost, some politics
          ... client environment, not ours).
          How do you configure WLS cluster in this environment? ( can the plug-in
          on one host "share" its info with a plug-in on another host? ).
          Currently, the plug-ins are configured to talk to WLS on localhost.
          Im only interested in replicating servlet session states. No EJBs are
          involved.
          Thanks,
          John
          

Answer 1

Take a look at:
          http://www.weblogic.com/docs51/cluster/planning.html#1035562
          "The proxy plug-in contains the load balancing logic for accessing servlets and JSPs in a WebLogic
          Server cluster. Proxy plug-ins also contain the logic for accessing the replica of a client's
          session state if the primary WebLogic Server hosting their session state fails"
          Gene Chuang
          Join Kiko.com!
          "Jesus M. Salvo Jr." <[email protected]> wrote in message
          news:[email protected]...
          > Gene,
          >
          > How does the "plugin will handle the load-balancing between the
          > clustered web servers" when "attaching the plugin to the WLS on the same
          > host" means ( on netscape's obj.conf file ):
          >
          > WebLogicHost=localhost WebLogicPort=7001
          >
          > ... therefore "attaching" the plugin ONLY to the WLS on the same host,
          > and NOT to the WLS on the other host?
          >
          >
          > With this, if I get to the page on host A, session is created, and if I
          > reload the page and by chance goes to host B ( as determined by Cisco LD
          > ), I get a new session and weblogic.log on host B does say ( as I have
          > instructed it when calling getSession( true ) ) "New session created".
          >
          > I first try getSession( false ), and if its null, as in this sample
          > scenario above, I call getSession( true ) at which I write toe the log
          > "New session created".
          >
          >
          > I know I could have tried in the obj.conf file:
          >
          > WebLogicCluster=<non-local-IP1>,<non-local-IP2>
          >
          >
          > ... but if I do this on both hosts, WLS / plug-in may get confused as it
          > said in the doc that the plug-in determines which one is the primary and
          > secondary servers. But what if one plug-in said that the main server is
          > host A while the other said the main server is host B?
          >
          >
          > Thanks,
          >
          > John
          >
          > Gene Chuang wrote:
          > >
          > > Each plugin should attach to the WLS on the same host; once attached, the plugin will handle
          the
          > > load-balancing between the clustered web servers.
          > >
          > > Our architecture is similar to yours; we have Cisco LD, Apache, Apache plugin, Weblogic web and
          > > Weblogic app.
          > > --
          > > Gene Chuang
          > > Join Kiko.com!
          > >
          > > "Jesus M. Salvo Jr." <[email protected]> wrote in message
          > > news:[email protected]...
          > > > The on-line documents regarding clustering talks about using a single
          > > > web server front-end with the WLS plug-in and the plug-in sending the
          > > > WLS request to multiple WLSs in a cluster.
          > > >
          > > > The environment that Im dealing with involves a Cisco LD load balancing
          > > > for two Netscape Servers .... and the two hosts where Netscape Servers
          > > > are loaded are also loaded with the NES plug-in and with WLS 5.1. ( Why
          > > > WLS is
          > > > not on a different host is another matter ... mostly cost, some politics
          > > > ... client environment, not ours).
          > > >
          > > > How do you configure WLS cluster in this environment? ( can the plug-in
          > > > on one host "share" its info with a plug-in on another host? ).
          > > > Currently, the plug-ins are configured to talk to WLS on localhost.
          > > >
          > > > Im only interested in replicating servlet session states. No EJBs are
          > > > involved.
          > > >
          > > >
          > > > Thanks,
          > > >
          > > > John