Yes. i can see few seconds time between node #1 and node #2 pickup. As per PDN i can see below definition of "Ignore duplicate file names". Do you think by enabling this resolve this issue as both nodes are picking the same file within fraction of seconds.  We do have a logic make the file as duplicate form code level but we are getting unnecessary alerts and we might miss original alert when we really receive duplicate file from source system.  Here my observation is Node #1 picked the file and file is under processing. As File processing was not completed file is still available in source location. Then somehow Node #2 picks same file which might causing this issue. is this correct assumption? 

Select to prevent the processing of a second or later file that has the same name as a previously processed file.

If selected, the system searches the Log-Service-File class for past instances of processing by any listener containing the current file name. If a match is found, the system:

1. Bypasses normal processing of the file
2. Copies the duplicate input file to the work directory
3. Saves the file with .dup as the file extension