Issue: PolicySync Fails with Error 503 Server Unavailable

Version 9

    Verified Product Versions

    Endpoint Manager 9.6Endpoint Manager 2016.xEndpoint Manager 2017.x



    • PolicySync.exe.log shows errors


    Request: exception - The remote server returned an error: (503) Server Unavailable. Request: failed get response from APMService. Exit PolicySync.exe with code -3




    POST /ApmService/PolicyRequest.asmx - 80 - - 503 2 0 62





    This is a Microsoft IIS error indicating your environment has maxed out its allowed number of connections to IIS.

    • 503.2 - Concurrent request limit exceeded.




    :  Because this deals with modifying configuration information for IIS, users assume all responsibility when implementing changes or modifications outlined in this information.


    Increase the allowed number of concurrent requests in IIS as outlined by Microsoft in the article:


    Click Start and then click Run.

    In the Run dialog box, type notepad %systemroot%\Microsoft.Net\Framework64\v2.0.50727\CONFIG\machine.config, and then click OK.

    Locate the processModel element that looks like this: <processModel autoConfig="true" />

    Replace the processModel element with the following value: <processModel enable="true" requestQueueLimit="15000" />

    Save and close the Machine.config file.


    For Windows Server 2008, in the Run dialog box, type appcmd.exe set config /section:serverRuntime /appConcurrentRequestLimit:<#of users * 1.5>.


    - Modifying the ASP.NET Request Queue Limit



    Note: appcmd.exe is located at %systemroot%\system32\inetsrv\appcmd.exe. It may be necessary to change directories within the command window to successfully initiate this command.