KB73059364: Connect Automation Engine to WebCenter outside the LAN

Context

Esko officially supports configurations where Automation Engine and WebCenter are not on the same LAN/ WAN. This article describes the limitations and extra efforts needed to optimize the workflow between Automation Engine and WebCenter in this case.

Although clearly an extra complexity, following are some scenarios where such configurations are used:

• Automation Engine and WebCenter are not owned by the same company. It is perfectly possible to upload from the Automation Engine to the WebCenter setup at a business partner.
• WebCenter is hosted.
• WebCenter is shared between multiple sites which are not on the same network.

1. What is different?
   

   WebCenter is designed to work entirely independent of Automation Engine. Therefore, the differences between having both within the same LAN and on different LANs are not that big. In short, following are the most important differences:

   • WebCenter must be reachable by Automation Engine. This is obvious but not always so easy. The Automation Engine computer must have a connection to the internet and have the ability to send HTTP requests through this connection. Specifically in case a proxy server is used, certain extra actions will need to be taken - see point 2 given below.
   • Approval feedback between Automation Engine and WebCenter works with a JMS messaging system. When Automation Engine and WebCenter are not in the same LAN, this needs to be configured separately. See the WebCenter Administration Guide - chapter “WebCenter Configuration” > section “Configure Workflow Approval Clients” for more information.
   • Upload from the Automation Engine to the WebCenter happens more efficiently when both are on the same LAN. In that case, the file transfers are done via simple copy instead of via HTTP uploads. 
   • Automation Engine at one site cannot be used as a graphic engine for a WebCenter on another site. This means that in practice, a WebCenter on a remote site must always be installed with an on-board graphics engine (OBGE).
   • Bitmap files (mostly screened bitmaps) cannot be uploaded by Automation Engine to a remote WebCenter.

   The difference is made based on the WebCenter and Automation Engine are in the same LAN setting in the Automation Engine configure, WebCenter sites. Make sure to always select this setting (it’s switched on by default) when they are in the same LAN since the link is much more performant.

2. Proxy servers and their influence on the WebCenter /Automation Engine configuration
   

   A proxy server services the requests of its clients by forwarding requests to other servers. The client is mostly a browser, but it can also be another computer program like the Automation Engine.

   The proxy server provides the resource by connecting to the specified server and requesting the service on behalf of the client. A proxy server may optionally alter the client's request or the server's response and sometimes, it may serve the request without contacting the specified server.
   
   

   A proxy server that passes all requests and replies unmodified is usually called a gateway or sometimes tunneling proxy.

   For the Automation Engine to WebCenter connectivity, proxy servers that just act as a gateway are ideal. No extra configuration is required.

   In the other case (not a pure gateway), it can happen that the proxy server is programmed to act differently than expected on the Automation Engine calls to WebCenter.

   • It might decide to just not pass them through and the Automation Engine to WebCenter upload fails.
   • It might request authentication and nobody is there to answer the authentication request since Automation Engine is an automatic program.
   • It might bother the JAVA viewing.
   • It might slow down the communication.
   • It might bother the JMS connectivity in the approval feedback.

   Most problems can be solved by bringing the proxy server closer to the ideal gateway situation. However, in many cases it is difficult to convince the local IT people to do any changes to the setup.

Procedure

Proxy problems are mostly detected because certain operations between the Automation Engine and the WebCenter fail:

• Upload from the Automation Engine to WebCenter fails.
• Approval feedback from WebCenter to Automation Engine fails.

Proxy problems are not the only possible reasons why these operations can fail. Other reasons are:

• Wrong parameters in the upload ticket (mistakes with user accounts, passwords, network address of the web server, etc).
• Broken networks.

The best way to troubleshoot is as follows:

• Check whether you can reach WebCenter from a normal internet browser from the Automation Engine computer. If that doesn’t work, first troubleshoot this. Check whether WebCenter itself is on the internet (can you reach it from anywhere?). If that works, try reaching Google from the Automation Engine computer. If that doesn’t work, your Automation Engine computer is not connected to the internet. Contact your local IT to get this fixed. If you can reach Google, but not WebCenter and you can reach WebCenter from outside, then the proxy settings could be the problem.
• If you can reach WebCenter from a browser but upload doesn’t work, then first check the connection in the Automation Engine configure (there is a Check button). If this works, double check the ticket settings. If it doesn’t work, it means that the Automation Engine doesn’t have the same abilities to go to the internet as a browser. Mostly this means that the browser has a proxy setting in use.
  

   

  
  

  In your browser, check the LAN settings for your internet connection. In the Internet Explorer, this is found under Internet Options > Connections. There, you normally can see whether a proxy server is used and what settings it uses for the HTTP connection. These same settings need to be used by the Automation Engine.

  You need:

  • Name of the proxy server for HTTP, further called proxyHost.
  • Port number, further called proxyPort.

  In some cases (not so common) it is also possible that the proxy server demands authentication. You might see this because an authentication window appears when trying to connect to Google or WebCenter via the browser. In that case you’ll also need a username and a password. You should get this from your local IT. This username is further called proxyUser and the password is proxyPassword.

  
  We have a tool (makeurlconnection.jar: http://webcenter2.esko.com/WebCenter_Inst/docdetails.jsp?docVerID=00002_0000004585&menu_file=mailto) to test a connection with these settings even before trying them out of Automation Engine. The tool is used as follows:

  • Save the makeurlconnection.jar file somewhere on a directory on the Automation Engine server.

  • Open a command prompt, go to that directory and type the following command:

    Simplest form: Java.exe -jar makeurlconnection.jar http://the_url_to_the_login_page_of_their_webcenter

    The above command supposes that java.exe is in the path. If not, you need to specify the location of java.exe, for example C:\Program Files\Java\jre1.6.0_01\bin\java.exe ... (other parameters as above). It also supposes that it is a Java 1.6. If not, you need to install Java 1.6 first.

    This checks whether a connection can be made without specifying anything about the proxy server. If this works, you get the webcenter login html code dumped on your screen (scroll back to verify this). If it doesn’t work, you either get an error message or it hangs (press Ctrl+C in that case).

  • In case it doesn’t work, try specifying the just found parameters. The most complex form is:

     

    Java.exe -Dhttp.proxyHost="name of the proxy server"
    
    Dhttp.proxyPort=”80”
    
    Dhttp.proxyUser="the_domain_if_applicable\user name"
    Dhttp.proxyPassword="guess what comes here"
    jar makeurlconnection.jar http://the_url_to_the_login_page_of_their_webcenter

    All the parameters are case-sensitive. Find help from local IT people to get you through this.

  • After performing these settings, you need to use them in the Automation Engine.

  • Run cfsedt2.bat in ..\bg_prog_fastserverctltnt_v070\com_win.

  • Browse to the keys as shown in the screenshot and modify the values. Do a net stop bgmd and net start bgmd to activate the changes. Then the upload from the Automation Engine to the WebCenter should work.