I have 2 load balanced WFEs. When I take one of them offline then website still works which means load balancer is working. But when I do IIS reset on one of those machines then the website doesn't work while IIS is resetting. Why is that?

  • Is everything running duplicated on both WFE's ? There may be a common service that is only activated on one of them. Taking the website offline leaves it running so you don't notice but when you IISReset nothing runs anymore and it manifests. Just a thought. – Cameron Verhelst Mar 18 '14 at 7:09
  • Have you tried the take offline test and IISreset test on each machine? Have same results? – Mark L Mar 18 '14 at 9:03
  • I did offline test on both machines and website worked. I did iisreset on WFE2 and website worked. But when I did iireset on WFE1 then website didn't work. – Frank Martin Mar 20 '14 at 12:49

It would help to know what load balancer you are using so I can help narrow the possible cause but the likely reason is detailed below.

If you are using a hardware based load balancer such as F5 LTM then it will load balance traffic across the two nodes on the ports you specify. You will need to setup monitors to probe the health of the nodes and based on the health it will react and route traffic to the other node etc. Typically, these monitors can check if a server is down, the port is down and, if the response time of the node is worse than the other, or if the website is serving a 200 response and much more. The capabilities of your load balancer will determine what these monitors can do for you. If your monitors are simply checking for a Ping on the node then it won't pick up that IIS is down while you do the iisreset and will continue to send that node traffic.

If you are using Windows NLB, you don't get features that allow you to route traffic based on health. The NLB isn't aware of the health of IIS. If the server is up, it'll get traffic. There isn't much more you can configure.

Hope this helps. Let me know if you need me to clarify anything further.


  • Oh this could be the reason. Because I am using Windows NLB so it might not know that the IIS is down. And the server itself is up so it thinks that WFE is working so I guess it sends traffic to it. – Frank Martin Mar 20 '14 at 12:50

You should refresh the addresses of the service applications. You can use the Start-SPTimerJob in PowerShell

Try using this command via Power Shell: Start-SPTimerJob job-spconnectedserviceapplication-addressesrefresh

Reference: https://sladescross.wordpress.com/category/load-balancing/

  • Please add more details to this answer – Robert Lindgren Mar 18 '14 at 14:49
  • When a load balancer is offline, web services addresses must change to the other WFE's web services addresses to let sharepoint use them. Try to run this command in PowerShell: Start-SPTimerJob job-spconnectedserviceapplication-addressesrefresh – user3132623 Mar 18 '14 at 16:18
  • Robert is suggesting you add more detail because right now it's not much more than just a link to a blog post. People change hosting providers, delete their blogs, etc all the time. If your link goes dead, then so does your answer. It would be very likely to get upvotes if you add your comment and some code examples as well as the link. – Robert Kaucher Mar 18 '14 at 17:28

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