Check Services with NLB and Failover Clustering

[fernando_tonial]

Hi,

We have a SIB to do in a customer and we want to know if the NLB (Network Load Balance) checks the SERVICES inside of the WINDOWS?

Thanks a lot

[Anonymous]

Fernando,

The local load balancer normally has a health check process to IIS to verify if the web server is available. Global load balancing is more of a DNS resolve process, I’m unsure how any failover testing is done for that.

Andy Marshall

GinfoS Advanced Technology Group

Hewlett-Packard Ltd

Tel.: +44 1772 652807

+44 560 109 3231

andy.marshall@hp.com<mailto:andy.marshall@hp.com>

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27/09/2013-05/10/2013

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09/05/2014-16/05/2014

[#3 · Accepted solution]

There are probes configured in your NLB to check which servers are accessible. Most of the time they are using ping which only tells the NLB if the server is up (connected to the network). You can set the NLB probes to check a web page on each server for status. If the NLB can access the page, it will get a status code of 200 from the web server which confirms that the web service is running on that server.

QlikView offers a status page (http://servername/QvAjaxZfc/QvsStatus.aspx ) which will return the status code 200 if the QlikView server service is running and other status codes for any issues with the service. With this status page, not only you get to check the web service but also the QlikView server service. However, if you have the web service and QlikView service running on different servers, you should not be using this page. In cases like these, we usually just point the probe to a static page on our web server.