Query on Clustering,Load Balancing and Dehydration in Oracle BPEL PM

Hi,
I had a Few queries on Dehydration ,Clustering and Load Balancing:
1) In section 5.1 "Use Case for Asynchronous Web Services",insertion of a dehydration point is mentioned.What do you exactly mean by this.Can a dehydration point be inserted explicitly?OR we have to put a wait activity or something so that dehydration happens?
2) If a dehydration point needs to be inserted explicity arent we assuming that the invoke-reply will take long?But this might not be the case always.Is is a lso possible that an asynchronous process is not a long running one.
3) Can we configure administratively ,how much time the process (say 10 seconds or so)waits after which it gets dehydrated?
4) Consider a load balancing scenario,where we have 2 BPEL PM's (PM1 and PM2) running on 2 different App Servers (SRV1 and SRV2)in an clustered environment.
Scenario:
1)We have an asynchronous process which makes a call to a human task activity.
2)A request from client comes for this process.
3) The load balancing server forwards it to PM1 on SRV1.PM1 processes the request and calls the human task.
4) PM1 has not dehydrated the process.
5) The response from the Human User comes back to the Load Balancer before the process is dehydrated by PM1.It forwards this response to PM2.PM2 searches for the Process based on the Cor-relation ID and does not find it.
Can you tell me how this scenario is handled?
I would be grateful if someone can answer these queries or direct me to some place where it is already explained.
Thanks
Dileep

1) In section 5.1 "Use Case for Asynchronous Web Services",insertion of a dehydration point is mentioned.What do you exactly mean by this.Can a dehydration point be inserted explicitly?OR we have to put a wait activity or something so that dehydration happens?
Insert a java snippet with "checkpoint();"
3) Can we configure administratively ,how much time the process (say 10 seconds or so)waits after which it gets dehydrated?
No, this is due to the performance of your database.

Similar Messages

Load balancing and fault tolerance in BPEL PM

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Have you seen these links?
http://www.oracle.com/technology/products/ias/hi_av/BPEL_HA_Paper.pdf
http://download-uk.oracle.com/docs/cd/B31017_01/integrate.1013/b28980/clusteringsoa.htm#CHDCGIEJ

Load balancing and clustering in sharepoint

Hi,
Still i am confuse about load balancing with cluster in sharepoint level.please let me know how to install and troubleshoot,how it is work, Advantage, etc..
Thanks,
Inguru

Hi Inguru,
Per my knowledge, SharePoint only supports Load balancing and SQL support clustering.
Here is a similar thread for you to take a look:
http://social.technet.microsoft.com/Forums/en-US/2b20d1d5-de35-486e-9b0e-37222a307615/clustering-and-load-balancing?forum=sharepointgeneralprevious
To configure load balancing for SharePoint, please follow the links below:
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Hardware clustering/load balancing/failover with Tomcat

Hello forum!
I recently bought a Cisco 1801, and it sure is capable! Anyhow, I've got a hobby website that is getting a fair bit of traffic - approaching too much for one node to handle and it's time to start thinking about distributing the load.
I'd like to do a little clustering of server nodes running Apache Geronimo, which is J2EE running atop Apache Tomcat. For the sake of keeping things generic, let's just call it Tomcat because it configures the same way.
I do not run Apache HTTP Server as a proxy, I only run Tomcat directly connected to the internet. I do this for performance reasons.
Anyhow, I'm wondering if any of you evil geniuses could suggest a way that I could cluster Tomcat nodes directly using the router to serve as a hardware load balancer and have the whole sticky session thing with failover, etc... All of the documents I find on the subject discuss clustering by way of Apache HTTP with Mod_JK.
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http://CardMeeting.com

This occurs rarely when the Tomcat process is not able to connect to the database. The database connection problem is an internal cause which manifests externally as missing fields in reports.
Workaround: Restart the Apache process and the Tomcat process. From the CLI on your CiscoWorks Server, enter the following commands in the specified sequence:
1. pdterm Apache
2. pdterm Tomcat
3. pdexec Tomcat
4. pdexec Apache

For a true load balancing and high-availability OHS, OPMN, and mod_oc4j

i have read this link of Enabling Clustering on oc4j9.0.4 standalone app server
http://www.oracle.com/technology/docs/tech/java/oc4j/htdocs/getstart.htm#1015479
To test the clustering, start up the load balancer by executing "java -jar loadbalancer.jar".
C:\OC4J_EXTENDED\j2ee\home>java -jar loadbalancer.jar
In a future release of Oracle Application Server, loadbalancer.jar will be
desupported. Because of this, we strongly suggest that you discontinue your use
of loadbalancer.jar in this release. Under high loads, loadbalancer.jar may not
function properly. For a true load balancing and high-availability solution,
please move to use OHS, OPMN, and mod_OC4J. For more information, please see
http://otn.oracle.com/products/ias/ohs/content.html
Balancer initialized...
what load balancer should i use for web clustering
<frontend host="balancer-host" port="balancer-port" />
balancer-host=localhost
balancer-port=80
for all nodes i mentioned same host and port in http-web-site.xml.Is it correct?
i completed all the steps and run http://localhost:6666/session/SessionServlet
i hit 3 times
in the different browser http://localhost:7777/session/SessionServlet
instead of coming 4 it starting from 1 only.

can i use this loadbalancer.jar or not?
how to mod_oc4j in standalone app server

Multiple dgraph clustering (load balancing) OOTB available?

Hello,
We have 2 dgraphs running in parallel having the same data to share the load of the clients.
I would like to know if there is any OOTB solution provided by Endeca where in these two dgraphs can share the load. OR I need to use an external load balancer for the same?
If there is any document that explains the configuration for OOTB Endeca solution, please let me know
Thanks!

Hi,
yes I know...
i tried to check if they were still available...but found none,
that's why I said if you want me to send them email me ...(I downloaded them from Eden ) and the files aren't too big
regards
Saleh
29/11/12 : copy of the document called Simple MDEX Load Balancing with Apache HTTP Server (Endeca)
Endeca Solution Article Simple MDEX Load Balancing with Apache HTTP Server
Endeca Solution Article
Simple MDEX Load Balancing with Apache HTTP Server
By Robert Dennis
Last Updated: December 2010
Endeca Product Versions: 5.0+
This document describes how to set up a simple load balancing and failover solution using Apache HTTP server. This provides a cost effective mechanism leveraging widely available open source technologies to address simple infrastructure needs. This document includes the following sections:
 Introduction
 Configuration Steps
 References
Endeca Solution Article Simple MDEX Load Balancing with Apache HTTP Server
Endeca Confidential 2 of 5
Introduction
Load balancers are the preferred solution for providing scalability, redundancy, and fail-over for MDEX Engine queries. Typically, load balancing and failover are accomplished with the use of dedicated load balancing hardware. For some Endeca implementations, however, a robust mechanism for load balancing may not be available or required by the customer. For more information on the basics of load balancing an Endeca application, see the “Endeca Load Balancing Best Practices” Solution Article available on EDeN.
This document describes the configuration steps involved in leveraging Apache’s default load balancing mechanisms to provide a simple load balancing solution for an Endeca application. In this scenario, Apache will sit between the Endeca presentation API housed in a web application and redundant MDEX engines. Apache performs the duties of a simple load balancer and failover broker, managing query requests from the application tier to specific MDEX engines.
Configuration Steps
The described configuration leverages Apache 2.2 HTTP Server as the load balancing mechanism between two identical MDEX engines all residing on a single server. The sample configuration expects the Apache HTTP server to be listening on port 5555 and the MDEX engines to be listening on ports 8000 and 8001. These can be changed as appropriate for a given environment.
1. In the Apache httpd.conf, enable the server for listening on port 5555.
Endeca Solution Article Simple MDEX Load Balancing with Apache HTTP Server
Endeca Confidential 3 of 5
2. Enable the following modules by un-commenting the appropriate loadmodule statements in the httpd.conf file. These modules include: mod_proxy, mod_proxy_balancer, mod_proxy_connect, mod_proxy_http, mod_negotiation.
3. Include the httpd-vhosts.conf file by un-commenting the appropriate line in the httpd.conf file.
4. Save the httpd.conf file and open the httpd-vhosts.conf file. Append the below information and save the file.
Endeca Solution Article Simple MDEX Load Balancing with Apache HTTP Server
Endeca Confidential 4 of 5
NameVirtualHost *:5555 <VirtualHost *:5555> ServerName localhost ProxyPass / balancer://dgraphs/ ProxyPassReverse / balancer://dgraphs/ <Proxy balancer://dgraphs> BalancerMember http://localhost:8000 loadfactor=1 retry=0 BalancerMember http://localhost:8001 loadfactor=1 retry=0 </Proxy> </VirtualHost> <Location /balancer-manager> SetHandler balancer-manager </Location>
The “retry” parameter associated with Balance Members disables the period of inactivity for a particular worker after Apache determines it is offline. The default is 60 seconds. It is recommended that this is set to a low number such as 0.
In environments where particular MDEX engines are targeted for additional load, the “loadfactor” parameter associated with Balance Members can be adjusted. Higher values ensure that the load balancing algorithm that is used will route the traffic load accordingly to specific Balance Members.
5. Restart Apache.
6. Within the UI application, configure the host and port of the HttpENEConnection to the host and port of the load balancer (e.g. localhost:5555).
Endeca Solution Article Simple MDEX Load Balancing with Apache HTTP Server
Endeca Confidential 5 of 5
Apache HTTP Server is now properly configured to serve as a load balancer for the MDEX Engines.
References
“Endeca Load Balancing Best Practices” Solution Article (EDeN)
Apache Module mod_proxy
Apache Module mod_proxy_balancer
Apache Module mod_proxy_connect
Apache Module mod_proxy_http
Apache Module mod_negotiation
Edited by: sabdelhalim on Nov 28, 2012 5:46 PM

OCS on a cluster with Load balancing and fail safe environment

Dear all,
i want to ask is there any documat or hints on how to do an OCS R2 installaiotn on 3 server with RAC option (clustered Fail Safe), how can i install OCS on a cluster with Load balancing and fail safe environment.
plz i need ur help
thanking u
[email protected]

Dear all,
i want to ask is there any documat or hints on how to do an OCS R2 installaiotn on 3 server with RAC option (clustered Fail Safe), how can i install OCS on a cluster with Load balancing and fail safe environment.
plz i need ur help
thanking u
[email protected]

WLS6.1sp1 stateful EJB problem = load-balancing and fail over

          I have three problem
          1. I have 2 clustered server. my weblogic-ejb-jar.xml is here
          <?xml version="1.0"?>
          <!DOCTYPE weblogic-ejb-jar PUBLIC '-//BEA Systems, Inc.//DTD WebLogic 6.0.0 EJB//EN'
          'http://www.bea.com/servers/wls600/dtd/weblogic-ejb-jar.dtd'>
          <weblogic-ejb-jar>
          <weblogic-enterprise-bean>
               <ejb-name>DBStatefulEJB</ejb-name>
               <stateful-session-descriptor>
               <stateful-session-cache>
                    <max-beans-in-cache>100</max-beans-in-cache>
                    <idle-timeout-seconds>120</idle-timeout-seconds>
               </stateful-session-cache>
               <stateful-session-clustering>
                    <home-is-clusterable>true</home-is-clusterable>
                    <home-load-algorithm>RoundRobin</home-load-algorithm>
                    <home-call-router-class-name>common.QARouter</home-call-router-class-name>
                    <replication-type>InMemory</replication-type>
               </stateful-session-clustering>
               </stateful-session-descriptor>
               <jndi-name>com.daou.EJBS.solutions.DBStatefulBean</jndi-name>
          </weblogic-enterprise-bean>
          </weblogic-ejb-jar>
          when i use "<home-call-router-class-name>common.QARouter</home-call-router-class-name>"
          and deploy this ejb, exception cause
          <Warning> <Dispatcher> <RuntimeException thrown b
          y rmi server: 'weblogic.rmi.cluster.ReplicaAwareServerRef@9 - jvmid: '2903098842
          594628659S:203.231.15.167:[5001,5001,5002,5002,5001,5002,-1]:mydomain:cluster1',
          oid: '9', implementation: 'weblogic.jndi.internal.RootNamingNode@5f39bc''
          java.lang.IllegalArgumentException: Failed to instantiate weblogic.rmi.cluster.B
          asicReplicaHandler due to java.lang.reflect.InvocationTargetException
          at weblogic.rmi.cluster.ReplicaAwareInfo.instantiate(ReplicaAwareInfo.ja
          va:185)
          at weblogic.rmi.cluster.ReplicaAwareInfo.getReplicaHandler(ReplicaAwareI
          nfo.java:105)
          at weblogic.rmi.cluster.ReplicaAwareRemoteRef.initialize(ReplicaAwareRem
          oteRef.java:79)
          at weblogic.rmi.cluster.ClusterableRemoteRef.initialize(ClusterableRemot
          eRef.java:28)
          at weblogic.rmi.cluster.ClusterableRemoteObject.initializeRef(Clusterabl
          eRemoteObject.java:255)
          at weblogic.rmi.cluster.ClusterableRemoteObject.onBind(ClusterableRemote
          Object.java:149)
          at weblogic.jndi.internal.BasicNamingNode.rebindHere(BasicNamingNode.jav
          a:392)
          at weblogic.jndi.internal.ServerNamingNode.rebindHere(ServerNamingNode.j
          ava:142)
          at weblogic.jndi.internal.BasicNamingNode.rebind(BasicNamingNode.java:36
          2)
          at weblogic.jndi.internal.BasicNamingNode.rebind(BasicNamingNode.java:36
          9)
          at weblogic.jndi.internal.BasicNamingNode.rebind(BasicNamingNode.java:36
          9)
          at weblogic.jndi.internal.BasicNamingNode.rebind(BasicNamingNode.java:36
          9)
          at weblogic.jndi.internal.BasicNamingNode.rebind(BasicNamingNode.java:36
          9)
          at weblogic.jndi.internal.RootNamingNode_WLSkel.invoke(Unknown Source)
          at weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:296)
          So do i must use it or not???
          2. When i don't use "<home-call-router-class-name>common.QARouter</home-call-router-class-name>"
          , there's no exception
          but load balancing does not happen. According to the document , there's must load
          balancing when i call home.create() method.
          my client program goes here
               DBStateful the_ejb1 = (DBStateful) PortableRemoteObject.narrow(home.create(),
          DBStateful.class);
               DBStateful the_ejb2 = (DBStateful) PortableRemoteObject.narrow(home.create(3),
          DBStateful.class);
          the result is like that
               the_ejb1 = ClusterableRemoteRef(203.231.15.167 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@4695a6)/397
               the_ejb2 = ClusterableRemoteRef(203.231.15.167 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@acf6e)/398
               or
               the_ejb1 = ClusterableRemoteRef(203.231.15.125 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@252fdf)/380
               the_ejb2 = ClusterableRemoteRef(203.231.15.125 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@6a0252)/381
               I think the result should be like under one... isn't it??
               the_ejb1 = ClusterableRemoteRef(203.231.15.167 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@4695a6)/397
               the_ejb2 = ClusterableRemoteRef(203.231.15.125 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@6a0252)/381
          In this case i think the_ejb1 and the_ejb2 must have instance in different cluster
          server
          but they go to one server .
          3. If i don't use      "<home-call-router-class-name>common.QARouter</home-call-router-class-name>",
          "<replication-type>InMemory</replication-type>" then load balancing happen but
          there's no fail-over
          So how can i get load-balancing and fail over together??


          I have three problem
          1. I have 2 clustered server. my weblogic-ejb-jar.xml is here
          <?xml version="1.0"?>
          <!DOCTYPE weblogic-ejb-jar PUBLIC '-//BEA Systems, Inc.//DTD WebLogic 6.0.0 EJB//EN'
          'http://www.bea.com/servers/wls600/dtd/weblogic-ejb-jar.dtd'>
          <weblogic-ejb-jar>
          <weblogic-enterprise-bean>
               <ejb-name>DBStatefulEJB</ejb-name>
               <stateful-session-descriptor>
               <stateful-session-cache>
                    <max-beans-in-cache>100</max-beans-in-cache>
                    <idle-timeout-seconds>120</idle-timeout-seconds>
               </stateful-session-cache>
               <stateful-session-clustering>
                    <home-is-clusterable>true</home-is-clusterable>
                    <home-load-algorithm>RoundRobin</home-load-algorithm>
                    <home-call-router-class-name>common.QARouter</home-call-router-class-name>
                    <replication-type>InMemory</replication-type>
               </stateful-session-clustering>
               </stateful-session-descriptor>
               <jndi-name>com.daou.EJBS.solutions.DBStatefulBean</jndi-name>
          </weblogic-enterprise-bean>
          </weblogic-ejb-jar>
          when i use "<home-call-router-class-name>common.QARouter</home-call-router-class-name>"
          and deploy this ejb, exception cause
          <Warning> <Dispatcher> <RuntimeException thrown b
          y rmi server: 'weblogic.rmi.cluster.ReplicaAwareServerRef@9 - jvmid: '2903098842
          594628659S:203.231.15.167:[5001,5001,5002,5002,5001,5002,-1]:mydomain:cluster1',
          oid: '9', implementation: 'weblogic.jndi.internal.RootNamingNode@5f39bc''
          java.lang.IllegalArgumentException: Failed to instantiate weblogic.rmi.cluster.B
          asicReplicaHandler due to java.lang.reflect.InvocationTargetException
          at weblogic.rmi.cluster.ReplicaAwareInfo.instantiate(ReplicaAwareInfo.ja
          va:185)
          at weblogic.rmi.cluster.ReplicaAwareInfo.getReplicaHandler(ReplicaAwareI
          nfo.java:105)
          at weblogic.rmi.cluster.ReplicaAwareRemoteRef.initialize(ReplicaAwareRem
          oteRef.java:79)
          at weblogic.rmi.cluster.ClusterableRemoteRef.initialize(ClusterableRemot
          eRef.java:28)
          at weblogic.rmi.cluster.ClusterableRemoteObject.initializeRef(Clusterabl
          eRemoteObject.java:255)
          at weblogic.rmi.cluster.ClusterableRemoteObject.onBind(ClusterableRemote
          Object.java:149)
          at weblogic.jndi.internal.BasicNamingNode.rebindHere(BasicNamingNode.jav
          a:392)
          at weblogic.jndi.internal.ServerNamingNode.rebindHere(ServerNamingNode.j
          ava:142)
          at weblogic.jndi.internal.BasicNamingNode.rebind(BasicNamingNode.java:36
          2)
          at weblogic.jndi.internal.BasicNamingNode.rebind(BasicNamingNode.java:36
          9)
          at weblogic.jndi.internal.BasicNamingNode.rebind(BasicNamingNode.java:36
          9)
          at weblogic.jndi.internal.BasicNamingNode.rebind(BasicNamingNode.java:36
          9)
          at weblogic.jndi.internal.BasicNamingNode.rebind(BasicNamingNode.java:36
          9)
          at weblogic.jndi.internal.RootNamingNode_WLSkel.invoke(Unknown Source)
          at weblogic.rmi.internal.BasicServerRef.invoke(BasicServerRef.java:296)
          So do i must use it or not???
          2. When i don't use "<home-call-router-class-name>common.QARouter</home-call-router-class-name>"
          , there's no exception
          but load balancing does not happen. According to the document , there's must load
          balancing when i call home.create() method.
          my client program goes here
               DBStateful the_ejb1 = (DBStateful) PortableRemoteObject.narrow(home.create(),
          DBStateful.class);
               DBStateful the_ejb2 = (DBStateful) PortableRemoteObject.narrow(home.create(3),
          DBStateful.class);
          the result is like that
               the_ejb1 = ClusterableRemoteRef(203.231.15.167 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@4695a6)/397
               the_ejb2 = ClusterableRemoteRef(203.231.15.167 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@acf6e)/398
               or
               the_ejb1 = ClusterableRemoteRef(203.231.15.125 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@252fdf)/380
               the_ejb2 = ClusterableRemoteRef(203.231.15.125 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@6a0252)/381
               I think the result should be like under one... isn't it??
               the_ejb1 = ClusterableRemoteRef(203.231.15.167 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@4695a6)/397
               the_ejb2 = ClusterableRemoteRef(203.231.15.125 weblogic.rmi.cluster.PrimarySecon
               daryReplicaHandler@6a0252)/381
          In this case i think the_ejb1 and the_ejb2 must have instance in different cluster
          server
          but they go to one server .
          3. If i don't use      "<home-call-router-class-name>common.QARouter</home-call-router-class-name>",
          "<replication-type>InMemory</replication-type>" then load balancing happen but
          there's no fail-over
          So how can i get load-balancing and fail over together??

Load Balancing and WLS primary server offset

I've got a load balancer in front of my WLS cluster, and I'm trying to
          set up load balancing based on WLS clustering. What I need to know to
          do this is the offset within the cookie that's responsible for
          determining which machine within the cluster to direct to.
          Any idea how I can get this information?
          thanks,
          cfraser


Chris Fraser wrote:
          > The proxy/plug-in solution sounds pretty cool, but I've got a high speed
          > Alteon Load Balancer already set up. I would prefer to use that as the load
          > balancer to the WL cluster rather than pay to bring another WLS online to do
          > pretty much what the load balancer, that I already own, can do. I know that
          > going this route means that we're probably not going to be able to do things
          > like failover to the secondary when the primary dies, but we will be able to
          > load balance and also have the ability to dynamically add/delete servers
          > from the list of available servers as they are brought up/down.
          In Memory session replication doesn't work without our plugins. I will have to
          do little bit of investigation to figure out if other persistence mechanism's
          would work without our plugins if you are interested in them. I have to remind
          you though that other types of persistence mechanism's we support are slower
          compared to in memory session replication.
          > Are there any plans to work with an Alteon or a Foundry to have their Load
          > Balancers act as the front end to a WLS cluster?
          Currently none. We are taking steps to make the plugin's and cluster more
          robust, we currently don't have any plans to work with other 3rd party vendors.
          > For us it would be ideal, because we wouldn't have to support another piece of
          > software, we would just
          > have to support the hardware based Alteon, which can handle thousands of
          > transactions per second.
          > I understand that the primary and secondary server information is available
          > in the sessionID, I'm just not quite sure how to extract it.
          This information is saved in the cookie. But I wouldn't count that, as we
          have plans to change this. I cannot give your more details.
          > Is there a particular offset within the session ID where it can always be
          > found?
          I don't quite get what you mean here.
          Hope this helps.
          - Prasad
          > thanks for the help,
          > cfraser
          > ----------
          > C h r i s t o p h e r A . F r a s e r
          > Director, Technology
          > macroplay.com, Inc.
          > [email protected]
          >
          > Viresh Garg wrote:
          >
          > > You should be using
          > > -- NES +NSAPI Plugin
          > > -- IIS + ISAPI Plugin
          > > -- WEblogic server acting as proxy
          > > -- Apache +Apache Plugin ( only in Denali)
          > >
          > > front-ending your Weblogic cluster
          > >
          > > These proxies/plug-ins are smart to do a lot of things like:
          > >
          > > -- Load balancing in weblogic cluster
          > > -- Adding/deleting servers dynamically in cluster when the servers
          > > join/leave Weblogic cluster
          > > -- failover to secondary when primary dies.
          > >
          > > As far as the information about primary and secondary is concerned it is
          > > available in session ID.
          > >
          > > --Viresh Garg
          > >
          > > Chris Fraser wrote:
          > >
          > > > I've got a load balancer in front of my WLS cluster, and I'm trying to
          > > > set up load balancing based on WLS clustering. What I need to know to
          > > > do this is the offset within the cookie that's responsible for
          > > > determining which machine within the cluster to direct to.
          > > >
          > > > Any idea how I can get this information?
          > > >
          > > > thanks,
          > > > cfraser

Load-balancing and fail-over between web containers and EJB containers

When web components and EJB components are run in different OC4J instances, can we achieve load-balancing and fail-over between web containers and EJB containers?
null

It looks like there is clustering, but not loadbalancing available for rmi
from the rmi.xml configuration. The application will treat any ejbs on the
cluster as one-to-one look-ups. Orion will go out and get the first ejb
available on the cluster. See the docs on configuring rmi.xml (and also the
note below).
That is a kind-of failover, because if machine A goes down, and the
myotherAejbs.jar are on machine B too, orion will go out and get the bean
from machine B when it can't find machine A. But it doesn't go machine A
then machine B for each remote instance of the bean. You could also specify
the maximum number of instances of a bean, and as one machine gets "loaded",
orion would go to the next available machine...but that's not really
loadbalancing.
That is, you can set up your web-apps with ejbs, but let all of the ejbs be
remote="true" in the orion-application.xml file:
<?xml version="1.0"?>
<!DOCTYPE orion-application PUBLIC "-//Evermind//DTD J2EE Application
runtime 1.2//EN" "http://www.orionserver.com/dtds/orion-application.dtd">
<orion-application deployment-version="1.5.2">
<ejb-module remote="true" path="myotherAejbs.jar" />
<ejb-module remote="true" path="myotherBejbs.jar" />
<ejb-module remote="true" path="myotherCejbs.jar" />
&ltweb-module id="mysite" path="mysite.war" />
... other stuff ...
</orion-application>In the rmi.xml you would define your clustering:
<cluster host="230.0.0.1" id="123" password="123abc" port="9127"
username="cluster-user" />
Tag that is defined if the application is to be clustered. Used to set up
a local multicast cluster. A username and password used for the servers to
intercommunicate also needs to be specified.
host - The multicast host/ip to transmit and receive cluster data on. The
default is 230.0.0.1.
id - The id (number) of this cluster node to identify itself with in the
cluster. The default is based on local machine IP.
password - The password configured for cluster access. Needs to match that
of the other nodes in the cluster.
port - The port to transmit and receive cluster data on. The default is
9127.
username - The username configured for cluster access. Needs to match that
of the other nodes in the cluster.

VPN load balancing and ASA !!!

Hi netpros,
I have a couple of questions about this and hope you might be able to assist me.
1.- Are VPN load balancing and failover (Active/Active) mutually exclusive ..? I mean they can't be used at the same time correct ..?
2.- How does the ASA handle the return traffic from the Internal LAN towards the remote client .. Because the cluster only requires ONE public virtual IP address, which will work for incoming packets .. but what about the return traffic which has knowledge of the DHCP scope's default gateway IP address only .. ? How gets the returned packet redirected from the default gateway IP address to the respective ASA internal IP address .?
3.- VPN load balancing only applies to remote clients using easy VPN technology (easy vpn client, hardware client , pIX using easy vpn client etc ) and does not work with static LAN-LAN tunnel .. correct ..?
Your comments are much appreciated

Hi Gilbert ..
1.- Thanks I wanted to make sure.
2.- I know that .. my question is in regards the return packets .. for example if I have the below IP schema:
ASA1: Public 20.20.20.20
Private 192.168.1.1
ASA2: Public 20.20.20.21
Private 192.168.1.2
Cluster virutal IP: 20.20.20.10
Default gateway for segment 192.168.1.0 is 192.168.1.1
Let's say that a vpn client tries to connect and the cluster instructs the client to connect to ASA2 20.20.20.21. The packets reach the internal server at 192.168.1.100. The internal server then sends the return packets back to the client by forwarding them to its default gateway which is 192.168.1.1 (ASA1). Here is my question .. how does the cluster handles this because the return packet are supposed to be directed to ASA2 192.168.1.2
3.- Any idea about this one ..?
Cheers,

Load balancing and rfc metadata repository in reciever rfc communication ch

hi.
i want to know the purpose of load balancing and rfc meta data repository in RFC communication channel.
and can u send me any examples on this load balancing.
waiting for your response.
bye.
regards.
seeta ram.

Hi Seeta Ram,
Load distribution is handled by the message server (there is one message server in an SAP System). When a user logs on, the message server assigns him or her to the application server that currently has the <b>smallest load</b>.
Well now you can understand that we use load balancing for better performance by distributing the work to different processes to balance or maintain the work load in SAP system.
For more information refer to this link
http://help.sap.com/saphelp_nw04/helpdata/en/28/75153a1a5b4c2de10000000a114084/content.htm
Regards
Sumit Bhutani

Advantages of using a webserver inbetween a load balancer and application servers

I am building out a new weblogic domain.
I am wondering which one of these configuration to go with:
1. Load balancer > weblogic servers
2. Load balancer > web server > weblogic servers
Could someone tell me what are the specific advantages of having web servers inbetween a load balancer and application servers (besides caching static data content and acting as a proxy)?
Thanks in advance
Srini

Other than hosting the static content, nothing much really. We have our load balancer go straight to WL for applications without static content and route to web server if there is static content. Easy enough to do it both ways, best of both worlds.

Load balancing and High Availability topology

Our Forms 6i client-server application currently runs on Citrix farm of 20 Windows 2000 boxes (IBM Blade Servers 2 CPU and 2 Gig Memory).
Application supports 2000 users.
We are moving to AS 10g r2, forms 10g and the goal is to use same hardware, 20 Windows boxes (or less), for intranet web deployment.
What will be our best choices for application Load balancing and High Availability?
Hardware load balancer, Web Cache, mod-oc4j? Combinations?
Any suggestions, best practices, your experience?

Gerd, I understand, that you are running 10g web forms through the browser, but using Citrix for deployment. This means that in addition to Application Server and Forms runtime sessions, it will be separate browser session opened for each user. What the advantage of this configuration?
Michael, we are aware, that Citrix is not supported by Oracle as a deployment platform. That only means that prior contacting Oracle Support we have to reproduce the problem in standard environment. It was never been a problem to reproduce problem :) We were using Citrix as a deployment platform for Forms 6i client/server for 4 years, but now we are forced to upgrade to 10g.
We are familiar with various Load balancing options available. The question is which option is the most "workable" in our case.

2 ISP load balancing and redundancy

Hello!!
Our small company has about 40 branches spreaded within city. Branches are connected by optic wire supplied by our ISP. So in ISP our branches are located in one VLAN. From every branch we created VPN tunnel to our server room in central office. Central office is like a cetner point. If optic wire fails to central office, there would no VPN tunnels and no network to all branches. Moreover, all the traffice goes through central office.
Now we decided to pave one more optic line to our central office. And that will increase bandwidth and redundancy.
Private network topology: There are no default gateways and ip-addresses. For examle, at first branch I will plug computer directly into media converter and at the second branch plug another computer to the media converter. After that this two computers became in one network. And can assign any ip addresses to them.
What I have: our firewall do enough work, don't want to overload it. But we have some free ports in our new cisco 3750. The question is how to do load balancing and redundanccy? Can it do load balancing according to traffic? And how load balance incoming traffic? For example, connection was established from branche's router, how this router will choose through which line make connection? By the way, at all branches we use noisy cisco
3700 series routers.

Sorry for upping 1 year old threat.
We talked to our Network Provider. They said "these two cables are coming from two different places, so there is no way to use etherchannel. You must use active-standby solution."
Relying on STP we just put two cables into 3750 stack. But with default STP settings, connection was very unstable, many packet losses and disconnections. So we found easy solution with "flex links", making one interface backup of the other. And only now I recognized that this is not a failover solution. Because, if network beyond media converter will down, link from media converter to switch would still up.
What could I do to make our L2 WAN redundant? Are there any additional STP settings.

Query on Clustering,Load Balancing and Dehydration in Oracle BPEL PM

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