Continue flow on certain specific Error in SSIS - sql-server-2005

Question

In SSIS 2005, I am using the FTP Task. I have a flow where when the package runs, it retrieves any files in a specific folder from FTP to a local folder.
Remote folder path is set by variable such as /root/abc/*abc.txt
The task works fine if there are files in that folder matching this criteria. If there are no files, the task fails with a file not found error!
How can I make SSIS not break the task in case this specific file not found error comes up simply becuase the remote folder had no matching files?
But, in case there is an error such as FTP server not able to login etc., then the task should throw the expected error.

Answer 1

Probably, you have found an answer to your question by now. Here is one possible way of achieving this. Script Task can be used to find the list of files present in an FTP folder path for a given pattern (say *.txt). Below example shows how this can be done.
Step-by-step process:
On the SSIS package, create an FTP Connection named FTP and also create 5 variables as shown in screenshot #1. Variable RemotePath contains the FTP folder path; LocalPath contains the folder where the files will be downloaed to; FilePattern contains the file pattern to find the list of files to download from FTP server; FileName will be populated by the Foreach loop container but to avoid FTP task design time error, it can be populated with / or the DelayValidation property on the FTP Task can be set to True.
On the SSIS package, place a Script Task, Foreach Loop container and FTP Task within the Foreach Loop container as shown in screenshots #2.
Replace the Main() method within the Script Task with the code under the Script Task Code section. Script Task will populate the variable ListOfFiles with the collection of files matching a given pattern. This example will first use the pattern *.txt, which yields no results and then later the pattern *.xls that will match few files on the FTP server.
Configure the Foreach Loop container as shown in screenshots #3 and #4. This task will loop through the variable **ListOfFiles*. If there are no files, the FTP task inside the loop container will not execute. If there are files, the FTP task inside the loop container will execute for the task for the number of files found on the FTP server.
Configure the FTP Task as shown in screenshots #5 and #6.
Screenshot #7 shows sample package execution when no matching files are found for the pattern *.txt.
Screenshot #8 shows the contents of the folder C:\temp\ before execution of the package.
Screenshot #9 shows sample package execution when matching files are found for the pattern *.xls.
Screenshot #10 shows the contents of the FTP remote path /Practice/Directory_New.
Screenshot #11 shows the contents of the folder C:\temp\ after execution of the package.
Screenshot #12 shows the package failure when provided with incorrect Remote path.
Screenshot #13 shows the error message related to the package failure.
Hope that helps.
Script Task Code:
C# code that can be used in SSIS 2008 and above.
Include the using statement using System.Text.RegularExpressions;
public void Main()
{
Variables varCollection = null;
ConnectionManager ftpManager = null;
FtpClientConnection ftpConnection = null;
string[] fileNames = null;
string[] folderNames = null;
System.Collections.ArrayList listOfFiles = null;
string remotePath = string.Empty;
string filePattern = string.Empty;
Regex regexp;
int counter;
Dts.VariableDispenser.LockForWrite("User::RemotePath");
Dts.VariableDispenser.LockForWrite("User::FilePattern");
Dts.VariableDispenser.LockForWrite("User::ListOfFiles");
Dts.VariableDispenser.GetVariables(ref varCollection);
try
{
remotePath = varCollection["User::RemotePath"].Value.ToString();
filePattern = varCollection["User::FilePattern"].Value.ToString();
ftpManager = Dts.Connections["FTP"];
ftpConnection = new FtpClientConnection(ftpManager.AcquireConnection(null));
ftpConnection.Connect();
ftpConnection.SetWorkingDirectory(remotePath);
ftpConnection.GetListing(out folderNames, out fileNames);
ftpConnection.Close();
listOfFiles = new System.Collections.ArrayList();
if (fileNames != null)
{
regexp = new Regex("^" + filePattern + "$");
for (counter = 0; counter <= fileNames.GetUpperBound(0); counter++)
{
if (regexp.IsMatch(fileNames[counter]))
{
listOfFiles.Add(remotePath + fileNames[counter]);
}
}
}
varCollection["User::ListOfFiles"].Value = listOfFiles;
}
catch (Exception ex)
{
Dts.Events.FireError(-1, string.Empty, ex.ToString(), string.Empty, 0);
Dts.TaskResult = (int) ScriptResults.Failure;
}
finally
{
varCollection.Unlock();
ftpConnection = null;
ftpManager = null;
}
Dts.TaskResult = (int)ScriptResults.Success;
}
VB code that can be used in SSIS 2005 and above.
Include the Imports statement Imports System.Text.RegularExpressions
Public Sub Main()
Dim varCollection As Variables = Nothing
Dim ftpManager As ConnectionManager = Nothing
Dim ftpConnection As FtpClientConnection = Nothing
Dim fileNames() As String = Nothing
Dim folderNames() As String = Nothing
Dim listOfFiles As Collections.ArrayList
Dim remotePath As String = String.Empty
Dim filePattern As String = String.Empty
Dim regexp As Regex
Dim counter As Integer
Dts.VariableDispenser.LockForRead("User::RemotePath")
Dts.VariableDispenser.LockForRead("User::FilePattern")
Dts.VariableDispenser.LockForWrite("User::ListOfFiles")
Dts.VariableDispenser.GetVariables(varCollection)
Try
remotePath = varCollection("User::RemotePath").Value.ToString()
filePattern = varCollection("User::FilePattern").Value.ToString()
ftpManager = Dts.Connections("FTP")
ftpConnection = New FtpClientConnection(ftpManager.AcquireConnection(Nothing))
ftpConnection.Connect()
ftpConnection.SetWorkingDirectory(remotePath)
ftpConnection.GetListing(folderNames, fileNames)
ftpConnection.Close()
listOfFiles = New Collections.ArrayList()
If fileNames IsNot Nothing Then
regexp = New Regex("^" & filePattern & "$")
For counter = 0 To fileNames.GetUpperBound(0)
If regexp.IsMatch(fileNames(counter)) Then
listOfFiles.Add(remotePath & fileNames(counter))
End If
Next counter
End If
varCollection("User::ListOfFiles").Value = listOfFiles
Dts.TaskResult = ScriptResults.Success
Catch ex As Exception
Dts.Events.FireError(-1, String.Empty, ex.ToString(), String.Empty, 0)
Dts.TaskResult = ScriptResults.Failure
Finally
varCollection.Unlock()
ftpConnection = Nothing
ftpManager = Nothing
End Try
Dts.TaskResult = ScriptResults.Success
End Sub
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