Karthik, Very elegant. I guess it sums up my experiences in general. NLB will work just fine if you don't have issues with ANY node and you simply want to balance between existing nodes. As long as something goes wrong on a node, you have no ability to automatically pull it out of the balance unless the service is stopped, or the machine is offline.
-----Original Message----- From: Action Request System discussion list(ARSList) [mailto:[email protected]] On Behalf Of Karthik Sent: Monday, September 10, 2012 11:45 AM To: [email protected] Subject: Re: MS Network Load Balancing (NLB) with AR Server Groups ** Hi, I just implemented NLB for server groups. NLB was implemented for Mid-tiers and also for App Server group. As someone has mentioned before, its does not provide all the different modes that other hardware load balancers do. only option is for load balancing based on the server load. However, there are some problems with NLB. For Ex: If Mid Tier 1 is down but the server hosting it still provides a heartbeat, clients are still sent to it. This poses a problem when it comes to balancing load to mid tier servers. But for app servers this can be handled using OOB provided configuration, "Enable lifespan" on mid tier config page. By enabling this, mid-tiers will understand if an app server is down and the requests will not be sent to the app servers. however, if the app servers have performance problems and are services are still up, requests will still be sent to them. Only way to mitigate the negative scenarios described above would be to stop a particular host from the NLB manager, while you are debugging the problem with the mid-tier being down/app server having performance issues. that said, below are some inportant configs you need to keep in mind: 1- load balancer should be configured in Multi cast mode if its NLB. Network guys should understand this. 2 - affinity should be set to None. 3 - load balancer name should be FQDN I.e. fully qualified domain name. Regarding point 2 above: this is applicable for only application load balancer. For mid tier load balancer(if you are planning to have one in place) the affinity parameter should be set to single. Sometimes, NLB is configured in unicast mode. in this case, there is a need to add an additional network adapter and this causes license issues as in unicast mode, the NLB makes the mac address of all the NLB hosts the same. to mitigate this, please follow the attached link to not allow the mac address to be the same for all the hosts: http://technet.microsoft.com/en-us/library/bb742455.aspx <http://technet.microsoft.com/en-us/library/bb742455.aspx> hope this helps. My personal and also per the article found in above link, its good to go for multi-cast mode. Regards, Karthik On 10 September 2012 22:49, Mauricio M. <[email protected]> wrote: ** Hello, thank you, what would be some of those specific configurations or capabilities? -Mauricio 2012/9/10 Longwing, LJ CTR MDA/IC <[email protected]> Mauricio, I recently re-looked at MS NLB and found it to be 'lacking' of proper load balancing configuration capabilities, but I haven't looked real close at it either. I much prefer an independent LB tool. -----Original Message----- From: Action Request System discussion list(ARSList) [mailto:[email protected]] On Behalf Of Mauricio M. Sent: Monday, September 10, 2012 11:06 AM To: [email protected] Subject: MS Network Load Balancing (NLB) with AR Server Groups ** Hello, Does anyone have any experience or feedback using Microsoft NLB for load balancing with AR System 7.6.04? There are a few old posts about NLB but nothing recent Thank you in advance, Mauricio _attend WWRUG12 www.wwrug.com ARSlist: "Where the Answers Are"_ _______________________________________________________________________________ UNSUBSCRIBE or access ARSlist Archives at www.arslist.org attend wwrug12 www.wwrug12.com ARSList: "Where the Answers Are" _attend WWRUG12 www.wwrug.com ARSlist: "Where the Answers Are"_ _attend WWRUG12 www.wwrug.com ARSlist: "Where the Answers Are"_ _______________________________________________________________________________ UNSUBSCRIBE or access ARSlist Archives at www.arslist.org attend wwrug12 www.wwrug12.com ARSList: "Where the Answers Are"
