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Test network load balancing RRS feed

  • Question

  • User91826606 posted

    Greetings,

    We have setup three Servers with Windows Server 2003 Standard Edition SP2. Each machine has the IP address of 192.168.1.2(Server1), 192.168.1.3(Server2) and 192.168.1.4(Server3). The Cluster IP is set on Server3 with IP address of 192.168.1.5 using Network Load Balancing Manager installed on Server3 itself. The subnet mask is configured as 255.255.255.0. The diagram connectivity is as follow:

    Server1(192.168.1.2) ----> Server3(192.168.1.4/[ClusterIP:192.168.1.5]) <----- Server2 (192.168.1.3)

    The two scenarios we wish to test are:

    1. Failover.- If  Server 1 down, Server 2 should take up the process. [Tested successfully].

    2. Load Balance. - send files(e.g. 10 files) through http and load balance by having 5 files in Server1 and 5 files in Server2.

    We have tested the above scenarios but failed to fully test scenario 2. The files or messages are sent to a single server only, which is dependent on the Priority that is set. For an example, if the Priority is set to 1 for Server1, all the files or messages will be sent to Server1.

    We appreciate if you could shine some light on how to test the second scenario to load balance the files or messages sent to the cluster IP configured on Server3 to both Server1 and Server2.

     Please correct me if my understanding of the load balancing as described above is wrong.

     Thanks

    Viknes

     

                                             

    Tuesday, January 5, 2010 12:01 AM

Answers

  • User989702501 posted

    What's the load weight configuration in NLB? by default is equal, so if you got 3 nodes then it is ~33% each and technically you will get first request node1, 2nd request node2, 3rd request node3, 4th request node1 and so on. Yet the request must be sort of in processing or transaction still ongoing, else if request is too fast, node1 may repick it again. so normally, I setup WCAT to send 100 requests to cluster..... then check the log files at my nodes to see how it split.. thought not exactly 50/50, but it was pretty ok, 58,42 or so.. Sometime I just open few browsers windows or machines, then keep pressing f5 to see the content changed. (put a simple html file which indicated the node name/etc)

    • Marked as answer by Anonymous Tuesday, September 28, 2021 12:00 AM
    Tuesday, January 5, 2010 5:05 AM

All replies

  • User989702501 posted

    What's the load weight configuration in NLB? by default is equal, so if you got 3 nodes then it is ~33% each and technically you will get first request node1, 2nd request node2, 3rd request node3, 4th request node1 and so on. Yet the request must be sort of in processing or transaction still ongoing, else if request is too fast, node1 may repick it again. so normally, I setup WCAT to send 100 requests to cluster..... then check the log files at my nodes to see how it split.. thought not exactly 50/50, but it was pretty ok, 58,42 or so.. Sometime I just open few browsers windows or machines, then keep pressing f5 to see the content changed. (put a simple html file which indicated the node name/etc)

    • Marked as answer by Anonymous Tuesday, September 28, 2021 12:00 AM
    Tuesday, January 5, 2010 5:05 AM
  • User-348984809 posted

    Thnask qbernard, interesting thoughts. what tools do you use for testing ?

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    Monday, March 29, 2010 5:26 PM
  • User989702501 posted
    tool ? typically WCAT.
    Friday, April 2, 2010 2:37 AM
  • User1779485512 posted
    Hi viknes21, Just want to ask some questions. I'm a beginner about Network Load Balancing, and i'm currently building a network load balancing for my assignment, did you install Network Load Balancing features into your server1 and server2 (webserver IIS)? Help Urgent. Thank You
    Saturday, September 25, 2010 10:36 PM
  • User989702501 posted
    You need to the NLB feature on the OS perspective and then configure it. Google Windows Server NLB and read on. If you stuck, post the specific issue you facing.
    Monday, September 27, 2010 6:13 AM
  • User1779485512 posted
    Sorry, I don't really get what you mean. So do I need to add NLB features on my Webserver 1 and Webserver2 ? Or only one NLB feature is enough on my NLB computer ? I have tried not to install NLB feature into webserver1 and webserver2, the NLB computer are not able to connect both webserver. Once I installs NLB feature into webserver1 and webserver2, then both webserver can be connect with NLB computer. *Confuse*. May I know what are the problem here ? I requested four computers Two web server running IIS, one computer handle NLB, and one computer act as internal client, so basically all computer within the same subnet. -Okay. Thank you for the reply. I will screen shot my work tomorrow and show the problem Im facing.
    Tuesday, September 28, 2010 4:30 AM
  • User989702501 posted
    Are you using the OS NLB feature included? like W2k3 NLB. if yes, each of the cluster node will need to have the NLB and configure with the same virtual cluster IP, depending on whether you use multicast or unicast, you may need to configure arp mac address mapping at switch level. so in your case your web1 and web2 will need to have NLB installed and configured. read this article. http://technet.microsoft.com/en-us/library/cc758834(WS.10).aspx
    Tuesday, September 28, 2010 9:07 AM
  • User1779485512 posted
    Hi, Im using Windows Server 2008 operating system. --- Four computers in a network. Two Web server IIS + NLB, one computer for DNS, and one computer act as external client for testing purposes. --- All servers and external client is connected to a switch. And the switch is connected to a Cisco Router. External Client IP = 192.168.1.2, Gateway 192.168.1.1. Web Server 1 = 10.0.35.11, Web Server 2 = 10.0.35.12. DNS = 10.0.35.15. Other than using WCat tools, do you have other tool to test NLB ? I'm planning to add some additional/add-on security features or any thing which can work with NLB into my DNS Server, such as monitoring NLB traffic tools ? Can you recommend me some tools which can work with NLB ? Thank You.
    Thursday, September 30, 2010 4:06 AM
  • User1779485512 posted
    Hi. I tried WCAT tools on my client computer, but not sure how it works. I installed and configured it based on this web site http://blogs.msdn.com/b/alikl/archive/2008/03/09/stress-test-asp-net-web-application-with-free-wcat-tool.aspx . -How should I configure the script.txt, distribution.txt and config.txt if I want a single client computer to send 100 request to my web server1 and webserver2 ? - And the RUN THE TEST part, the command is wcctl -c config.txt -d distribution -s script.txt -a localhost (May I know what is the localhost means ? Is it My cluster IP ? or www.abc.com (DNS) ? ) After that open second command prompt and enter wcclient.exe localhost (May I know what is the localhost means ? Is it My client computer IP address ?) Confuse. Thank You for the reply
    Saturday, October 2, 2010 5:32 AM
  • User989702501 posted
    You don't need wcat to test your NLB, you can just do a simple browse to test it. WCAT is more on web app stress testing. there are no native nlb traffic monitoring tools, you can either look at the OS native network interface counter data or IIS log file/etc.
    Hi, Im using Windows Server 2008 operating system. --- Four computers in a network. Two Web server IIS + NLB, one computer for DNS, and one computer act as external client for testing purposes. --- All servers and external client is connected to a switch. And the switch is connected to a Cisco Router. External Client IP = 192.168.1.2, Gateway 192.168.1.1. Web Server 1 = 10.0.35.11, Web Server 2 = 10.0.35.12. DNS = 10.0.35.15. Other than using WCat tools, do you have other tool to test NLB ? I'm planning to add some additional/add-on security features or any thing which can work with NLB into my DNS Server, such as monitoring NLB traffic tools ? Can you recommend me some tools which can work with NLB ? Thank You.
    Friday, October 8, 2010 9:36 PM
  • User989702501 posted
    Unless you are trying to stress your app in NLB mode, you can skip WCAT. and to stress test it then you should configure WCAT against the NLB IP. it depends on what your want to test, you need read more about WCAT setup, about the controller and client and the ubr env file on the scripts, etc.
    Friday, October 8, 2010 9:38 PM
  • User1779485512 posted
    Hi. Oh I see. Thanks qbernard. I have two question, the first question is Do you have any features or tools which can work with Microsoft Network Load Balancing ? for example to improve the Network Load Balancing security? And the second question is Other than these two (failover and load balance) testing, do you have other ways to test Network Load Balancing? To show my lecturer about the benefits of having Network Load Balancing. -Thank You-
    Saturday, October 9, 2010 12:16 PM
  • User989702501 posted
    1. Not sure what tool you referring, but at command line you can use 'wlbs.exe' or 'nlb.exe' to check the status and manage the NLB cluster. you can also go to the NLB adapter to configure or in w2k3 you can use NLB Manager (UI based) 2. NLB is more load balance, failover only at network level as this is not an app level NLB. so if your app is not working say crash/etc. traffic will still get route to the app stack via network. as at network layer the ip is still listening file. To test it, typically i have a script that display the physical host name at a page. so when i browse i know which host it is serving the request. you can also look at the iis log files to see if both nodes are getting the requests.
    Monday, October 11, 2010 9:18 PM
  • User-42981448 posted

    Hello,

     

    Can your please tell me, is there any use of cluster IP to test the NLB based web application?

    Wednesday, December 19, 2012 6:56 AM
  • User989702501 posted

    Errr.. of coz. in order to test NLB setup, you will need to test against the virtual or cluster IP.

    You can test individual node IP, however to see if the cluster really load balancing, virtual IP is the way to go and it supposes to redirect requests to each node depending on the cluster setup/etc.

    Tuesday, January 1, 2013 8:12 PM
  • User1852639975 posted

    Hi,

    I'm trying to do the same thing. I've got IIS hosting my test pages on two different 2008 clustered servers.

    Design:

    1. Server 1 = servera = 192.168.42.51

    2. Server 2 = serverb = 192.168.42.52

    3. Cluster (created using NLB manager on serverA) = test.cluster.com = 192.168.42.250

    Now how do i test my cluster ? when i do a wlbs query, I get proper response that my clusters are ok.

    What I tried was, I stopped http service on my IIS on serverA and tried browsing, but then I get a page cannot be displayed, where If I'm right, I should get a test page from serverB. Then I re-enabled the HTTP service on serverA and then disabled the NIC card, then to I get a page cannot be displayed error.

    I'm kinda stuck here, and cannot think of a way to try out this cluster before deploying it at a production site. Which will be hosting my Web Application.

    Can someone please shed some light on this ? I have a project I need to finish.

    Is there a way that I can configure a policy where I can assign a set number of rule, that diverts clients to serverB if a limit is reached on serverA or if number of users are reached ?

    Thanks and Regards,

    Aj.

    Sunday, November 10, 2013 2:43 AM