Symptoms
I get the following Error from time to time on our Dev/Test All-in-One K2 Server.
61012 Exception from message source k2service@denallix.com: System.Net.WebException: The request failed with HTTP status 503: Service Unavailable.
at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall)
at System.Web.Services.Protocols.SoapHttpClientProtocol.InvokeAsyncCallback(IAsyncResult result)
Diagnoses
This error may be related to email/notification sending/Smartactions processing if Smartactions is enable or if you are using EWS to send email.
Resolution
Please check the "K2hostserver.exe.config" file located at "C:Program Files(x86)K2 blackpearlHost ServerBin" on the K2 server. How does the following nodes look in your environment:
<sourceCode.smartActions.directoryCatalog>
<catalogs>
<add path="SmartActions" />
</catalogs>
</sourceCode.smartActions.directoryCatalog>
<system self="K2:DENALLIXK2Service" enableListeners="true" allowAmbiguity="true" />
Please also run the "ConnectionStringEditor.exe" located in that same "C:Program Files(x86)K2 blackpearlHost ServerBin" directory. How does the EWS destinations and connection string look with regards to AutoDiscovery and the EWS URL?
If the EWS is load balanced, it may also be that there is a bad EWS node in which causes intermittent 503 Service Unavailable error when K2 attempts to access/interact with the EWS.
Customer discovered that some Exchange Server maintenance had occurred that likely resulted in 503 Service Unavailable to the EWS.
