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Is the user agent for Traffic Manager guaranteed? RRS feed

  • Question

  • I would like to know if the user agent that Traffic Manager sends as part of it's probing for cloud service endpoints is guaranteed to NOT change. Details for this are explained next.

    I use the IIS URL Rewrite module and its rules to ensure canonical URLs and redirect the client to the canonical URL if the incoming request is not to the desired canonical URL. For example, if my site is example.cloudapp.net and my domain is www.example.com, we perform 301 redirects from example.cloudapp.net to www.example.com.

    I see that the user agent traffic manager current sends is:

    Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; GTMProbe 1.0)

    I want to exclude requests by Traffic Manager from the IIS URL Rewrite rule so that the probing behavior doesn't trigger a redirect, to do this I need to know if the user agent string, specifically the "GTMProbe" portion, is *guaranteed to always* be used in current and future versions of Traffic Manager. Without this guarantee, I could set up the redirect rule now, but in the future if the GTMProbe portion of the user agent is removed or renamed, Traffic Manager could start to follow a redirect, think my cloud service is offline due to it being redirected away from the endpoint it's monitoring, and cause problems for the load balancing rules that have been defined.




    • Edited by Alan M. _ Monday, September 22, 2014 6:49 PM
    Monday, September 22, 2014 6:45 PM

Answers

  • Hi Alan,

    An idea on feedback.azure.com (in the Networking section, DNS/Traffic Manager category) is the best way to track requests.

    A question for you: before locking down the UA string, we might want to change it to something more descriptive, e.g.

    Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Azure Traffic Manager 1.0)<o:p></o:p>

    Would you have any concerns about this?

     - Jonathan

    • Marked as answer by Alan M. _ Thursday, September 25, 2014 9:41 PM
    Thursday, September 25, 2014 1:47 PM

All replies

  • Hi,

    We're working on your query. Will get back to you with our findings, at the earliest.

    Thank you,

    Arvind

    Tuesday, September 23, 2014 2:36 AM
  • Hi,

    As of now, there is no assurance that the "GTMProbe" parameter may remain the same.

    However, you may raise a technical support ticket to seek suggestions / best practices around the system architecture that you've setup.

    http://azure.microsoft.com/en-us/support/options/

    Thank you,

    Arvind

    Tuesday, September 23, 2014 4:14 PM
  • That was not the response I was expecting or hoping for.

    I have to consider Azure documentation to be the official description of expectations for users of Traffic Manager. If it isn't documented and published on the web somewhere, I can't expect any back channel support ticket to be official.

    The documentation on http://msdn.microsoft.com/en-us/library/azure/dn339013.aspx, section "How Monitoring Works" has a diagram showing a sequence of interactions between Traffic Manager and an endpoint. From the example in the documentation, the information I'm asking for clarification on is step 1, where it says 'GET – The Traffic Manager monitoring system performs a GET on the path and file you specified in the monitoring settings.'

    Is this the only documentation available that explains the interaction between traffic manager and a cloud service's endpoint? Is there any more official documented information on step 1?

    Tuesday, September 23, 2014 4:47 PM
  • Hi Alan,

    Thank you for the feedback.  Fixing the User Agent string is an interesting request--and not one we've seen before.  I'll discuss with my colleagues whether this is something we can lock down and be happy for customers to take a dependency on.

    Regards,

    Jonathan Tuliani

    Program Manager

    Azure Networking - DNS and Traffic Manager

    Wednesday, September 24, 2014 1:51 PM
  • Hi Jonathan,

    Thank you for considering this. How will we find out if this request has been accepted? Through this forum post or should I create an idea on feedback.azure.com and link to it from here?

    Alan

    Wednesday, September 24, 2014 2:45 PM
  • Hi Alan,

    An idea on feedback.azure.com (in the Networking section, DNS/Traffic Manager category) is the best way to track requests.

    A question for you: before locking down the UA string, we might want to change it to something more descriptive, e.g.

    Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Azure Traffic Manager 1.0)<o:p></o:p>

    Would you have any concerns about this?

     - Jonathan

    • Marked as answer by Alan M. _ Thursday, September 25, 2014 9:41 PM
    Thursday, September 25, 2014 1:47 PM
  • Hi Jonathan,

    I don't personally have any concerns about a more descriptive UA string, as long as the name prior to the version number doesn't change. Something in the UA string needs to be fixed and uniquely identifiable as coming from Traffic Manager.

    I've created the idea on feedback.azure.com, http://feedback.azure.com/forums/217313-networking-dns-traffic-manager-vpn-vnet/suggestions/6486357-formalize-the-traffic-manager-user-agent-string.

    I'll mark your last reply as the answer.

    Thanks!

    Alan



    • Edited by Alan M. _ Thursday, September 25, 2014 9:41 PM
    Thursday, September 25, 2014 9:40 PM