I just retested, to be sure, and there is no impact from setting “include file 
attributes” to False – stopping a flow pointed at a folder tree that had 
already processed the files, adding one file, then restarting it, the flow only 
picked up the new file.  And it still includes the critical attributes of 
filename, path and creation date.  For my use case, this is an appropriate and 
valuable setting.  Mike

From: James McMahon <[email protected]>
Sent: Saturday, March 20, 2021 5:26 PM
To: [email protected]
Subject: Re: speeding up ListFile

When we set “include file attributes” to False, does that in any way impact 
ListFile’s ability to track and retrieve new files by state?

On Fri, Mar 19, 2021 at 1:08 PM Mark Payne 
<[email protected]<mailto:[email protected]>> wrote:
It’s hard to say without knowing what’s taking so long. Is it simply crawling 
the directory structure that takes forever? If so, there’s not a lot that can 
be done, as accessing tons of files just tends to be slow. One way to verify 
this, on Linux, would be to run:

ls -laR

I.e., a recursive listing of all files. Not sure what the analogous command 
would be on Windows.

The “Track Performance” property of the processor can be used to understand 
more about the performance characteristics of the disk access. Set that to true 
and enable DEBUG logging for the processor.

If there are heap concerns, generating a million FlowFiles, then you can set a 
Record Writer on the processor so that only a single FlowFile gets created. 
That can then be split up using a tiered approach (SplitRecord to split into 
10,000 Record chunks, and then another SplitRecord to split each 10,000 Record 
chunk into a 1-Record chunk, and then EvaluateJsonPath, for instance, to pull 
the actual filename into an attribute). I suspect this is not the issue, with 
that mean heap and given that it’s approximately 1 million files. But it may be 
a factor.

Also, setting the “Include File Attributes” to false can significantly improve 
performance, especially on a remote network drive, or some specific types of 
drives/OS’s.

Would recommend you play around with the above options to better understand the 
performance characteristics of your particular environment.

Thanks
-Mark


On Mar 19, 2021, at 12:57 PM, Mike Sofen 
<[email protected]<mailto:[email protected]>> wrote:

I’ve built a document processing solution in Nifi, using the ListFile/FetchFile 
model hitting a large document repository on our Windows file server.  It’s 
nearly a million files ranging in size from 100kb to 300mb, and files types of 
pdf, doc/docx, xsl/xslx, pptx, text, xml, rtf, png, tiff and some specialized 
binary files.  The million files is distributed across tens of thousands of 
folders.

The challenge is, for an example subfolder that has 25k files in 11k folders 
totalling 17gb, it took upwards of 30 minutes for a single ListFile to generate 
a list and send it downstream to the next processor.  It’s running on a PC with 
the latest gen core i7 with 32gb ram and a 1TB SSD – plenty of horsepower and 
speed.  My bootstrap.cnf has the java.arg.2=-Xms4g and java.arg.3=-Xmx16g.

Is there any way to speed up ListFile?

Also, is there any way to detect that a file is encrypted?  I’m sending these 
for processing by Tika and Tika generates an error when it receives an 
encrypted file (we have just a few of those, but enough to be annoying).

Mike Sofen

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