Troubleshooting Connectivity problems between Web Front End and Conversion servers

The Muhimbi Document Converter for SharePoint is generally deployed using a distributed architecture where one or more Web Front End Servers communicate with one or more separate servers that run the Muhimbi Conversion Service. As the communication medium is HTTP (web services) over port 41734 this is generally very efficient and easy to troubleshoot.

The location / address of the Conversion Server can be configured in our Central Administration Screen (Application Management / Muhimbi Document Converter Settings in SP2007 or General Application Settings / Muhimbi Document Converter Settings in SP2010). By default this setting is set to

              http://localhost:41734/Muhimbi.DocumentConverter.WebService/

If Central Administration and the Conversion Service run on the same system then carrying out a connectivity test in Central Admin will succeed as ‘localhost’ is a correct address and the Conversion Service is running on the same system.

However, when trying to communicate with the Conversion Service from one of the Web Front End Servers ‘localhost’ points to the WFE, not the server that runs the Conversion Service. As a result you will get an error like “ An unexpected error occurred while processing your request, for details see the server’s Windows Application Event Log”

To solve this problem change ‘localhost’ to the name of the server that runs the conversion Service (or the name of the virtual host defined on your load balancer when running multiple conversion servers).

If you are still getting errors after changing the host name then there may be another connectivity problem. The main reason for this is the outgoing TCP port 41734 being blocked on the Front End Servers or the incoming port 41734 being blocked on the Conversion Server. You can confirm this as follows:

  1. Log in to the desktop of the WFE. Preferably using the account the Application Pool runs under.

  2. Open a web browser and navigate to: http://Conversion Server Host Name:41734/Muhimbi.DocumentConverter.WebService/

Check that a page is opened with the title “DocumentConverterService Service”

Although the above described connectivity test proves that your environment has been configured correctly in 99% of the cases, we have encountered one situation where McAfee Intrusion Detection Software was blocking requests from our software while allowing the same requests from Internet Explorer. If you are running Intrusion Detection Software, and are experiencing problems with our software, then please temporarily disable the IDS to see if that resolves the situation.