Load balancing not happending but fail over is for Read only Entity beans

Question

          The following are the configuration.
          Two NT servers with WL5.1 sp9 having only EJBs(Read only entity beans)
          One Client with WL5.1 sp9 having servlet/java application as
          EJB client.
          I am trying to make a call like findbyprimarykey in one of the
          entity bean. I could see the request is being directed only to the one of the
          server always. When I bring that server, fail over is happening to the other server.
          Here are the settings I have in the ejb-jar.xml :
                    <entity>
                         <ejb-name>device.StartHome</ejb-name>
                         <home>com.wl.api.device.StartHome</home>
                         <remote>com.wl.api.device.StartRemote</remote>
                         <ejb-class>com.wl.server.device.StartImpl</ejb-class>
                         <persistence-type>Bean</persistence-type>
                         <prim-key-class>java.lang.Long</prim-key-class>
                         <reentrant>False</reentrant>
                         <resource-ref>
                              <res-ref-name>jdbc/wlPool</res-ref-name>
                              <res-type>javax.sql.DataSource</res-type>
                              <res-auth>Container</res-auth>
                         </resource-ref>
                    </entity>
          Here are the settings I have in the weblogic-ejb-jar.xml.
          <weblogic-enterprise-bean>
                    <ejb-name>device.StartHome</ejb-name>
                    <caching-descriptor>
                         <max-beans-in-cache>50</max-beans-in-cache>
                         <cache-strategy>Read-Only</cache-strategy>
                         <read-timeout-seconds>900</read-timeout-seconds>
                    </caching-descriptor>
                    <reference-descriptor>
                         <resource-description>
                              <res-ref-name>jdbc/wlPool</res-ref-name>
                              <jndi-name>weblogic.jdbc.pool.wlPool</jndi-name>
                         </resource-description>
                    </reference-descriptor>
                    <enable-call-by-reference>False</enable-call-by-reference>
                    <jndi-name>device.StartHome</jndi-name>
               </weblogic-enterprise-bean>
          Am I doin any mistake in this?
          Any one's help is appreciated.
          Thanks
          Suresh
          

Answer 1

we are using 5.1
          "Gene Chuang" <[email protected]> wrote in message
          news:[email protected]...
          > Colocation optimization occurs if your client resides in the same
          container (and also in the same
          > EAR for 6.0) as your ejbs.
          >
          > Gene
          >
          > "Suresh" <[email protected]> wrote in message
          news:[email protected]...
          > > Ok....the ejb-call-by-reference set to true is making the call to one
          server
          > > only. i am not sure why it is. I removed the property name and it
          works.
          > > Also I have one question, in our prduct environment, when i cache the
          ejb
          > > home it is not doing the load balancing. can any one help me for that.
          > > thanks
          > >
          > > Mike,
          > > From the sample pgm I sent, even from single client calls get load
          > > balanced.
          > >
          > > Suresh
          > >
          > >
          > > "Gene Chuang" <[email protected]> wrote in message
          > > news:[email protected]...
          > > > In WL, LoadBalancing will ONLY WORK if you reuse your EJBHome! Take
          your
          > > StartEndPointHome lookup
          > > > out of your for loop and see if this fixes your problem.
          > > >
          > > > I've seen this discussion in ejb-interest, and some other vendor
          (Borland,
          > > I believe it is), brings
          > > > up an interesting point: Clustering and LoadBalance is not in the
          J2EE
          > > specs, hence implementation
          > > > is totally up to the vendor. Weblogic loadbalances from the remote
          > > interfaces (EJBObject, EJBHome,
          > > > etc..), while Borland loadbalances from JNDI Context lookup.
          > > >
          > > > Let me suggest a third implmentation: loadbalance from BOTH Context
          > > lookup as well as stub method
          > > > invocation! Or create a smart replica-aware list manager which
          persists
          > > on the client thread
          > > > (ThreadLocal) and is aware of lookup/evocation history. Hence if I do
          the
          > > following in a client
          > > > hitting a 3 node cluster, I'll still get perfect round-robining
          regardless
          > > of what I do on the
          > > > client side:
          > > >
          > > > InitialContext ctxt = new InitialContext();
          > > > EJBHome myHome = ctxt.lookup(MY_BEAN);
          > > > myHome.findByPrimaryKey(pk); <== hits Node #1
          > > > myHome = ctxt.lookup(MY_BEAN);
          > > > myHome.findByPrimaryKey(pk); <== hits Node #2
          > > > myHome.findByPrimaryKey(pk); <== hits Node #3
          > > > myHome = ctxt.lookup(MY_BEAN);
          > > > myHome.findByPrimaryKey(pk); <== hits Node #1
          > > > ...
          > > >
          > > >
          > > > Gene
          > > >
          > > > "Suresh" <[email protected]> wrote in message
          > > news:[email protected]...
          > > > > Mike ,
          > > > >
          > > > > Do you have any reasons for the total number of machines to be 10.
          > > > >
          > > > > I tried with 7 machines.
          > > > >
          > > > >
          > > > > Here is my sample client java application running individual in the
          > > seven
          > > > > machines.
          > > > >
          > > > > StartEndPointHome =
          > > > > (StartEndPointHome)ctx.lookup("dev.StartEndPointHome");
          > > > > for(;;)
          > > > > {
          > > > > // logMsg(" --in loop "+currentTime);
          > > > > if (currentTime > nextRefereshTime)
          > > > > {
          > > > > logMsg("****- going to call");
          > > > > currentTime=getSystemTime();
          > > > > nextRefereshTime=currentTime+timeInterval;
          > > > > StartEndPointHome =
          > > > > (StartEndPointHome)ctx.lookup("dev.StartEndPointHome");
          > > > > long rndno=(long)(Math.random()*10)+range;
          > > > > logMsg(" going to call remotestub"+rndno);
          > > > > retVal =
          > > > >
          > >
          ((StartEndPointHome)getStartHome()).findByNumber("pe"+rndno+"_mportal_dsk36.
          > > > > mportal.com");
          > > > >
          > > > > logMsg("**++- called stub");
          > > > > }
          > > > >
          > > > >
          > > > >
          > > > > The range value is different for each of the machines in the
          cluster.
          > > > >
          > > > > If the first request starts at srv1, all request starts hitting the
          same
          > > > > server.
          > > > > If the first request starts at srv2, all request starts hitting the
          same
          > > > > server.
          > > > >
          > > > > I have the following for the url , user and pwd values for the
          context
          > > .
          > > > >
          > > > > public static String url="t3://10.11.12.14,10.11.12.117:8000";
          > > > > public static String user="guest";
          > > > > public static String password="guest";
          > > > >
          > > > >
          > > > >
          > > > > It would be great if you could help me.
          > > > >
          > > > > Thanks
          > > > > suresh
          > > > >
          > > > >
          > > > > "Mike Reiche" <[email protected]> wrote in message
          > > > > news:[email protected]...
          > > > > >
          > > > > > If you have only one client don't be surprised if you only hit one
          > > server.
          > > > > Try
          > > > > > running ten different clients and see if the hit the same server.
          > > > > >
          > > > > > Mike
          > > > > >
          > > > > >
          > > > > > "suresh" <[email protected]> wrote:
          > > > > > >
          > > > > > >The following are the configuration.
          > > > > > >
          > > > > > > Two NT servers with WL5.1 sp9 having only EJBs(Read only entity
          > > beans)
          > > > > > >
          > > > > > > One Client with WL5.1 sp9 having servlet/java application as
          > > > > > > EJB client.
          > > > > > >
          > > > > > >
          > > > > > >I am trying to make a call like findbyprimarykey in one of the
          > > > > > >entity bean. I could see the request is being directed only to
          the
          > > one
          > > > > > >of the
          > > > > > >server always. When I bring that server, fail over is happening
          to
          > > the
          > > > > > >other server.
          > > > > > >
          > > > > > >
          > > > > > >Here are the settings I have in the ejb-jar.xml :
          > > > > > > <entity>
          > > > > > > <ejb-name>device.StartHome</ejb-name>
          > > > > > > <home>com.wl.api.device.StartHome</home>
          > > > > > > <remote>com.wl.api.device.StartRemote</remote>
          > > > > > > <ejb-class>com.wl.server.device.StartImpl</ejb-class>
          > > > > > > <persistence-type>Bean</persistence-type>
          > > > > > > <prim-key-class>java.lang.Long</prim-key-class>
          > > > > > > <reentrant>False</reentrant>
          > > > > > > <resource-ref>
          > > > > > > <res-ref-name>jdbc/wlPool</res-ref-name>
          > > > > > > <res-type>javax.sql.DataSource</res-type>
          > > > > > > <res-auth>Container</res-auth>
          > > > > > > </resource-ref>
          > > > > > > </entity>
          > > > > > >
          > > > > > >
          > > > > > >Here are the settings I have in the weblogic-ejb-jar.xml.
          > > > > > >
          > > > > > ><weblogic-enterprise-bean>
          > > > > > > <ejb-name>device.StartHome</ejb-name>
          > > > > > >
          > > > > > > <caching-descriptor>
          > > > > > > <max-beans-in-cache>50</max-beans-in-cache>
          > > > > > > <cache-strategy>Read-Only</cache-strategy>
          > > > > > > <read-timeout-seconds>900</read-timeout-seconds>
          > > > > > > </caching-descriptor>
          > > > > > >
          > > > > > > <reference-descriptor>
          > > > > > > <resource-description>
          > > > > > > <res-ref-name>jdbc/wlPool</res-ref-name>
          > > > > > > <jndi-name>weblogic.jdbc.pool.wlPool</jndi-name>
          > > > > > > </resource-description>
          > > > > > > </reference-descriptor>
          > > > > > > <enable-call-by-reference>False</enable-call-by-reference>
          > > > > > > <jndi-name>device.StartHome</jndi-name>
          > > > > > > </weblogic-enterprise-bean>
          > > > > > >
          > > > > > >
          > > > > > >Am I doin any mistake in this?
          > > > > > >
          > > > > > >Any one's help is appreciated.
          > > > > > >Thanks
          > > > > > >Suresh
          > > > > >
          > > > >
          > > > >
          > > >
          > > >
          > >
          > >
          >
          >