Great! Thank you! From: Action Request System discussion list(ARSList) [mailto:arslist@ARSLIST.ORG] On Behalf Of Axton Sent: Tuesday, September 20, 2011 11:21 AM To: arslist@ARSLIST.ORG Subject: Re: Software load balancer with AR Server and Mistier
** http://documents.bmc.com/supportu/documents/61/98/186198/186198.pdf The information is a bit vague in regards to load balancer configuration in front of the midtier/web servers, but note that in the whitepaper, everywhere it says that session persistence is not required, it refers to it as the load balancer between the midtier and arservers or in front of the arservers. The release notes make the following statement: http://documents.bmc.com/supportu/documents/43/74/184374/184374.pdf New load balancer configuration options If your AR System uses a hardware load balancer between the mid tier servers and AR System servers, BMC recommends configuring that load balancer without using a sticky bit by using the Connection Settings page in the BMC Remedy Mid Tier Configuration tool. Note that it does not state to turn it off for the load balancer in front of the mid-tier. You might be able to get away without setting up session persistence with the later versions of the midtier since the API does not have a native library dependency (assuming they implemented the serializable interface for all the non-native session specific things), but there is extra configuration you need to do with your J2EE container. For Tomcat, see here: http://tomcat.apache.org/tomcat-6.0-doc/cluster-howto.html To run session replication in your Tomcat 6.0 container, the following steps should be completed: - All your session attributes must implement java.io.Serializable - Uncomment the Cluster element in server.xml - If you have defined custom cluster valves, make sure you have the ReplicationValve defined as well under the Cluster element in server.xml - If your Tomcat instances are running on the same machine, make sure the tcpListenPort attribute is unique for each instance, in most cases Tomcat is smart enough to resolve this on it's own by autodetecting available ports in the range 4000-4100 - Make sure your web.xml has the <distributable/> element - If you are using mod_jk, make sure that jvmRoute attribute is set at your Engine <Engine name="Catalina" jvmRoute="node01" > and that the jvmRoute attribute value matches your worker name in workers.properties - Make sure that all nodes have the same time and sync with NTP service! - Make sure that your loadbalancer is configured for sticky session mode. So even with Tomcat cluster configurations the load balancer must have session persistence. I imagine the strategy with the above statements is to support a session moving from one node to another node in the event a node fails, not to simply allow any random request to go to any node. Again, the J2EE container cluster configuration may or may not work. I can't find anything stating experimentation either way. Axton On Tue, Sep 20, 2011 at 9:21 AM, Richard Copits <richard....@bwc.state.oh.us<mailto:richard....@bwc.state.oh.us>> wrote: ** How can I get a copy of the whitepaper? Thanks. From: Action Request System discussion list(ARSList) [mailto:arslist@ARSLIST.ORG<mailto:arslist@ARSLIST.ORG>] On Behalf Of Axton Sent: Tuesday, September 20, 2011 10:18 AM To: arslist@ARSLIST.ORG<mailto:arslist@ARSLIST.ORG> Subject: Re: Software load balancer with AR Server and Mistier ** I believe you still need session persistence with the mid-tier in 7.6. You do not (and have not really) required session persistence with the ARServer. A whitepaper available for 7.6 details this. The timeout on the load balancer needs to match or exceed the session timeout of your mid-tier application. If you are using a single sign on solution the mid-tier session timeout needs to be less than or equal to the SSO session timeout. So this would be a valid combination: Mid-tier Session Timeout: 60 minutes SSO Session Timeout: 120 minutes Load Balancer Session Persistence Expiration: 60 minutes In order for a J2EE application to not require session persistence a number of things have to be in place: - all objects in the container must be serializable - the container nodes in the farm must be configured as a cluster (session information must be serialized) There are some things that make me believe this is not possible with the midtier. Some information that is session specific is written to disk. I doubt these can be properly replicated between the J2EE containers. Axton On Tue, Sep 20, 2011 at 4:53 AM, debug ars <debug....@gmail.com<mailto:debug....@gmail.com>> wrote: ** Thanks Ken. We have search all articles and also went through documentation related to this. [We found that in 7.6.04 Midtier there are few additional configuration parameters available in which may not require stickiness to be set on load balancer. I have not tried those options yet though.] We have finalized on crossroads after careful review of all three. I will post my comments once we complete our testing. On Tue, Sep 20, 2011 at 7:10 AM, Cecil, Ken <kce...@hubbell.com<mailto:kce...@hubbell.com>> wrote: ** I have not done any testing but do recall seeing several Mistier related BMC knowledge base articles where the cause of the issues were related to Load Balancer use and settings like stickiness. Make sure you do a search on the support sight for load balancer and review them... Ken Cecil Hubbell Incorporated From: Action Request System discussion list(ARSList) [mailto:arslist@ARSLIST.ORG<mailto:arslist@ARSLIST.ORG>] On Behalf Of debug ars Sent: Monday, September 19, 2011 5:56 AM To: arslist@ARSLIST.ORG<mailto:arslist@ARSLIST.ORG> Subject: Software load balancer with AR Server and Midtier ** We are exploring various options to setup our test environment in server group with load balancer. Does anyone tried to use software load balancer for AR Server Group and Midtier? If yes, can you share details like, which software, version, configuration parameters like stickiness, timeout etc? [We have identified three with which we will be experimenting - crossroads, balanceAG and haproxy] -- Cheers Amen _attend WWRUG11 www.wwrug.com<http://www.wwrug.com> ARSlist: "Where the Answers Are"_ ******************************************************************* This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. 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