I’ve written before about how IIS healthchecks can spam application servers because IIS web farms are not directly linked to application pools. IIS is designed that any web application (application pool) can route a request to any web farm defined on the system. This means that all the application pools on a system read in all web farm configurations, and then believe that they are supposed to monitor the healthchecks on the web farms. Because of that, the more application pools on a server the more healthchecks that occur.
The issue was introduced in the first version of Web Farm Framework 1.1, but continues within the latest release of Application Request Routing 3.0 (Latest Release 1/25/2018, Web PI Version 3.0.1988).
I first discovered the problem when working on a Windows 2008 server, and was able to reproduce it on a Windows 2012R2 after that. I then filed a Microsoft Support ticket (#116110914917188) in which the product team did try to create a hotfix. But, the fix didn’t work and the ticket was closed stating that the issue would be fixed in a future release of IIS.
I’ve recently re-tested the feature in Windows Server 2016 and 2019. Both of which have the same problematic behavior. There’s a good chance that Application Request Routing is the subsystem which implements web farms, so it might not be an IIS specific issue. It might be that Application Request Routing needs to be updated.
0 comments:
Post a Comment