I am getting several exceptions on the CMS Master server, such as the one shown below.

ManagedPoolThread #12 00:08:09 ERROR Exception in UrlAgent (url: /sitecore/service/keepalive.aspx)
Exception: System.Net.WebException
Message: The remote server returned an error: (503) Server Unavailable.
Source: System
   at System.Net.WebClient.DownloadDataInternal(Uri address, WebRequest& request)
   at System.Net.WebClient.DownloadData(Uri address)
   at Sitecore.Web.WebUtil.ExecuteWebPage(String url, NameValueCollection headers)
   at Sitecore.Tasks.UrlAgent.Run()

My Sitecore CMS is version 7.0 I have separate Master Server and Content Delivery servers configured as well. This error does not occur within the Content Delivery servers

Any ideas what could be be causing this?

  • Have you tried the solutions provided on Sitecore's knowledge base website? See kb.sitecore.net/articles/376036.
    – Thomas D
    Nov 10, 2016 at 10:26
  • I am getting a HTTP 503, which is not one of the scenarios in your reference article
    – Julius A
    Nov 10, 2016 at 11:18
  • Just a thought...if this is an internal environment, check if the app_pool identity is an AD/Domain user account and the password has expired. - That is only if your organization has password policy in place.
    – hdvti
    Dec 2, 2016 at 1:53
  • Check information information agents and tasks here: community.sitecore.net/technical_blogs/b/sitecorejohn_blog/… You can find agent in sitecore.config
    – user16181
    Aug 28, 2018 at 3:29

1 Answer 1


You need to add localhost as a binding and scheduled the UrlAgent to use the localhost address.

  • 1
    Could you please add an example of what you mean by "scheduled the UrlAgent to use the localhost address"? With a configuration example, preferably. Dec 2, 2016 at 15:06

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