OLE/COM & Connect:Direct

Day 11

Sometimes we want to be able to automate tasks with regard to Connect:Direct.  On Windows we could do this using batch files (.bat or .cmd), or with an application using the Connect:Direct Windows SDK.  My preferred way is to use some form of VBScript and the OLE/COM interface that the Connect:Direct Windows SDK provides.

That sounds more complicated that it really is.  I'll show an example Windows Script Host (WSH) script that uses the OLE/COM interface to connect to the local node and send/receive files  with a remote node.

Start by looking at the example below from the comment "Processing starts here" where you will see the creation of an object of type "CD.Node".  If my memory serves me well this is not well documented in the Connect:Direct Windows SDK manual.

Once we have an object that represents our local node in my case called "NICKE" we can make a connection with our credentials.  In this example the user name and password are empty strings and it makes the connection based on how the "CD Client Connection Utility" is setup.  This utility allows you to define several user credentials and which one is to be used as the default when none are given as in my example below.

The rest of the script then goes on to perform a transfer using the "CDSend" function to a remote node called "CD.OTHER", check for an error and then perform a receive of a file and then another check for an error.  Both "CDSend" & "CDRecv" make use of a generic function "CDTransfer" to perform a file transfer with the direction of the transfer passed as a parameter which is then used to generate a dynamic Connect:Direct process which is the submitted using the "Node.Submit" function and then the statistics for the process just submitted and executed are analysed and the highest condition code returned to the caller of the "CDTransfer" function.

At the end of the script the connection with the local node is disconnected and the "Node" object de-allocated.

The script below can either be run by double-clicking directly on the ".vbs" script in the file explorer or by giving the name of the script as a parameter to the "CSCRIPT.EXE" program as follows:

C:\> cscript cdvbsdk.vbs

In the next post I will an alternative method of driving Connect:Direct from VBScript.

---

' Windows Script Host Sample Connect:Direct Script. 
' 
' Includes ability to push and pull files to/from the other Node. 
 
Dim Node        ' Represents the Connect Direct Node we are using. 
Dim procs       ' A collection of process records. 
Dim proc        ' An individual process record. 
Dim stats       ' A collection of statistic records. 
Dim stat        ' An individual statistic record. 
 
' Connect:Direct condition codes values 
 
warningConditionCode = 4 
errorConditionCode   = 8 
 
 
 
 
Function CDTransfer (fromFile, toFile, otherNode, direc) 
 
        If direct = "PUSH" then 
                localOrRemote = "LOCAL" 
                remoteOrLocal = "REMOTE" 
        else 
                localOrRemote = "REMOTE" 
                remoteOrLocal = "LOCAL" 
        End If 
 
        ' The process text to be submitted. 
 
        txtProcess = "TRANSFER PROCESS"                 + vbCrLf _ 
                + "     MAXDELAY=UNLIMITED"             + vbCrLf _ 
                + "     REMOTE=" & otherNode            + vbCrLf _ 
                + "     HOLD = NO"                      + vbCrLf _ 
                + "STEP01 COPY  FROM ("                 + vbCrLf _ 
                + "     FILE=" & fromFile               + vbCrLf _ 
                + "     " & localOrRemote               + vbCrLf _ 
                + "     TO ("                           + vbCrLf _ 
                + "     " & remoteOrLocal               + vbCrLf _ 
                + "     FILE=" & toFile                 + vbCrLf _ 
                + "     DISP=(RPL))"                    + vbCrLf _ 
                + "PEND"                                + vbCrLf
 
 
        set proc = Node.Submit(txtProcess)             ' Submit the process 
 
        ' Get the statistics regarding the process that has now finished. 
 
        set stats = Node.SelectStats("SELECT STATISTICS PNUMBER=" & proc.ProcessNumber) 
 
        ' If any step in the process has a condition code greater than "warning" we have a problem. 
 
        highestConditionCode =0 
 
        For Each stat in stats
 
                if stat.ConditionCode > highestConditionCode then 
                        highestConditionCode = stat.ConditionCode
                End If 
 
        Next 
 
        If highestConditionCode > warningConditionCode then 
 
                CDTRansfer = highestConditionCode
 
        End If 
 
End Function 
 
 
 
 
Function CDSend ( fromfile, toFile, otherNode ) 
        CDSend = CDTransfer ( fromfile, toFile, otherNode, "PUSH" ) 
End Function 
 
Function CDRecv ( fromfile, toFile, otherNode ) 
        CDRecv = CDTransfer ( fromfile, toFile, otherNode, "PULL" ) 
End Function 
 
 
' ------------------------------------------------------------------------------------------ 
' 
' Processing starts here 
' 
Set Node = CreateObject("CD.Node")              ' Make the OLE/COM connection to Connect:Direct 
 
Node.Connect "NICKE","",""      ' Sign on 
 
exitcode = 0 
 
rtc = CDSend ( "c:\temp\input.txt", "c:\temp\output.txt", "CD.OTHER") 
 
if rtc > warningConditionCode then 
        wscript.echo "Send Failed" 
        exitcode = exitcode + rtc
End If 
 
rtc = CDRecv ( "c:\temp\input.txt", "c:\temp\recv.txt", "CD.OTHER") 
 
if rtc > warningConditionCode then 
        wscript.echo "Recv Failed" 
        exitcode = exitcode + rtc
End If 
 
' You need to disconnect from the Node or you will leave cscript or wscript processes hanging around 
Node.Disconnect 
Set Node=Nothing 
Wscript.Quit(exitcode) 

---

FileAgent: Wood from the trees

Day 10

So last post we were about to start the FileAgent and test our FileAgent rule and associated C:D process.  First check that your Connect:Direct server is up and running.   You can do this on Windows by using the "CD Admin Tool" that you will find in the start menu for Connect:Direct.  It will show you whether or not the Connect:Direct server is started by showing a green traffic light for up and running and a red traffic light for stopped.  You can start the Connect:Direct server by right clicking the traffic light for your node and selecting "Start".  You can alternatively use the "services" control panel to check/start/stop the Connect:Direct service.

 Start the C:D Requester as we will be using that to monitor the activity of Connect:Direct, and also looking at the statistics files for any possible errors.  Double click the "Process Monitor" in the left hand pane of the requester and fill in the form as follows.

Here you can see that I have set it to update the display of what's happening with Connect:Direct every second.  Also double click the "Select Statistics" in the left hand pane of the Requester and fill in the following way:

Here I'm saying that I want the last 5 minutes worth of statistics and I want that list of statistics updated every minute.  So if anything fails while I'm trying to get the FileAgent rule or process working I can find out what happened quickly.  I find it also convenient to tile the "Process Monitor" & "Select Statistics" windows which you can do by using one of the toolbar buttons on the right in the Requester window.

I also open a file explorer on the directory to be watched by the FileAgent.  In our FileAgent rule the source file should be deleted from the watch directory only after successful transmission of the source file to its destination.  I usually create a test file in the directory above the watch directory and update the contents and save the file before dropping it in the watch directory for FileAgent to see.

Above you can see I'm in the directory above with the candidate test file before dropping it into the watch directory "DataABC".

FileAgent looks at the watch directory every minute depending on the configuration and if it finds a candidate that matches one of its rules it records the fact and decides to come back in another minute to see if the file is still growing in size.  If so it waits again until it believes the file has been finished writing to by either a local application or if it was a file being received by Connect:Direct from a remote node.

So you should start FileAgent and then leave it a minute or so to settle before dropping the updated file in the watch directory.  Then you have to be patient and wait a couple of minutes more before you might see some activity in Connect:Direct.

Open a command prompt and navigate to the FileAgent install directory. In my case that is "C:\Program Files\FileAgent".  Although on Windows the FileAgent is installed as a Windows service with manual startup.  However for testing it is often easier to run the FileAgent from the command line in verbose mode and re-directing the output to a log file.

I waited for a minute or so and then updated the data file using my favourite editor and then copied the file into the watch directory. I then watched the "Process Monitor" window and saw the following indicating that the C:D process was being run:

When the "Select Statisics" window refreshed I found the following:

Here I have highlighted the statistic row of interest showing a record type of "CTRC" which stands for Copy Termination ReCord and a condition code "CC" of 0 indicating that the transfer was a success.  Double clicking on that row will give a more detailed view of the statistic record:

So there you can see a successful transfer of the file to the remote node.

You can stop the FileAgent that you started from the command line either by pressing the CTRL+C keys if you are in a hurry and not worried about properly shutting down the FileAgent.  If you were more concerned about that you would create a file in the installation directory of FileAgent called "shut" which signals to FileAgent it should shutdown.  I consider myself working in a test environment so I use CTRL+C as I am the only one using this particular environment.

If you were to look in the FileAgent.log file that the FileAgent created you will see why the option that created the information was called "verbose".  It is sometimes very difficult to see the wood for the trees when looking at this kind of output. I myself use an editor with syntax highlighting to help me more easily see the things I'm looking for.

 Here I have highlighted in green the fact that the C:D process was submited, and in the next few lines you see that submit command was accepted.  You can also see in the lines above that one that the FileAgent variables get substituted before the C:D process is submitted to Connect:Direct.

So that's FileAgent in a flash.  It can be a bit tricky to set-up initially, but it can save you from having to write batch/wsh/shell scripts and makes it easy for applications to send/recieve data without being too tightly coupled with Connect:Direct.  What could be easier than just moving a file into a directory for it to be sent on its way?  

In many cases you can just use the single Connect:Direct process template you saw earlier for any additional FileAgent rules you might add for Windows/UNIX destinations.  At a later date I will show you how you can use FileAgent together with a script to generate dynamically specialised C:D processes for a variety of platforms while keeping the FileAgent configuration simple.