I have identified that calling Java's File.listFiles() over a SAMBA folder from a Win 7 client is extremely slow, actually almost 100 times slower than from a Mac client. (Both clients are running Java 7). Both clients are naturally on the same 1GB LAN. A customer has tested from his Win XP client and received far better performance than from his Win7 client. Does anyone know how to resolve this?
Some test data, including timing: Listing 31 folders over SAMBA ("QNAP" NAS disk):
Win 7:
listing \\nas\Public\David\Remote Stocks: 0.0s listing \\nas\Public\David\Remote Stocks\Animals: 0.093s listing \\nas\Public\David\Remote Stocks\Animals\.jalbum: 0.312s listing \\nas\Public\David\Remote Stocks\Animals\.jalbum\thumbs: 0.405s listing \\nas\Public\David\Remote Stocks\album: 1.248s listing \\nas\Public\David\Remote Stocks\album\Animals: 1.31s listing \\nas\Public\David\Remote Stocks\album\Animals\thumbs: 1.388s listing \\nas\Public\David\Remote Stocks\album\Animals\slides: 1.762s listing \\nas\Public\David\Remote Stocks\album\Animals\res: 2.542s listing \\nas\Public\David\Remote Stocks\album\Sports: 2.761s listing \\nas\Public\David\Remote Stocks\album\Sports\thumbs: 2.839s listing \\nas\Public\David\Remote Stocks\album\Sports\slides: 3.229s listing \\nas\Public\David\Remote Stocks\album\Sports\res: 3.978s listing \\nas\Public\David\Remote Stocks\album\res: 4.196s listing \\nas\Public\David\Remote Stocks\album\Scenic: 4.695s listing \\nas\Public\David\Remote Stocks\album\Scenic\thumbs: 4.773s listing \\nas\Public\David\Remote Stocks\album\Scenic\slides: 5.194s listing \\nas\Public\David\Remote Stocks\album\Scenic\res: 5.99s listing \\nas\Public\David\Remote Stocks\album\People: 6.208s listing \\nas\Public\David\Remote Stocks\album\People\thumbs: 6.302s listing \\nas\Public\David\Remote Stocks\album\People\slides: 6.692s listing \\nas\Public\David\Remote Stocks\album\People\res: 7.472s listing \\nas\Public\David\Remote Stocks\.jalbum: 7.659s listing \\nas\Public\David\Remote Stocks\Sports: 7.768s listing \\nas\Public\David\Remote Stocks\Sports\.jalbum: 7.909s listing \\nas\Public\David\Remote Stocks\Sports\.jalbum\thumbs: 7.987s listing \\nas\Public\David\Remote Stocks\Scenic: 8.486s listing \\nas\Public\David\Remote Stocks\Scenic\.jalbum: 8.642s listing \\nas\Public\David\Remote Stocks\Scenic\.jalbum\thumbs: 8.72s listing \\nas\Public\David\Remote Stocks\People: 9.282s listing \\nas\Public\David\Remote Stocks\People\.jalbum: 9.422s
Same listing on Mac:
listing /Volumes/Public/David/Remote Stocks: 0.0s listing /Volumes/Public/David/Remote Stocks/Animals: 0.013s listing /Volumes/Public/David/Remote Stocks/Animals/.jalbum: 0.018s listing /Volumes/Public/David/Remote Stocks/Animals/.jalbum/thumbs: 0.022s listing /Volumes/Public/David/Remote Stocks/album: 0.027s listing /Volumes/Public/David/Remote Stocks/album/Animals: 0.03s listing /Volumes/Public/David/Remote Stocks/album/Animals/thumbs: 0.032s listing /Volumes/Public/David/Remote Stocks/album/Animals/slides: 0.034s listing /Volumes/Public/David/Remote Stocks/album/Animals/res: 0.038s listing /Volumes/Public/David/Remote Stocks/album/Sports: 0.04s listing /Volumes/Public/David/Remote Stocks/album/Sports/thumbs: 0.042s listing /Volumes/Public/David/Remote Stocks/album/Sports/slides: 0.046s listing /Volumes/Public/David/Remote Stocks/album/Sports/res: 0.05s listing /Volumes/Public/David/Remote Stocks/album/res: 0.052s listing /Volumes/Public/David/Remote Stocks/album/Scenic: 0.058s listing /Volumes/Public/David/Remote Stocks/album/Scenic/thumbs: 0.064s listing /Volumes/Public/David/Remote Stocks/album/Scenic/slides: 0.068s listing /Volumes/Public/David/Remote Stocks/album/Scenic/res: 0.074s listing /Volumes/Public/David/Remote Stocks/album/People: 0.08s listing /Volumes/Public/David/Remote Stocks/album/People/thumbs: 0.082s listing /Volumes/Public/David/Remote Stocks/album/People/slides: 0.085s listing /Volumes/Public/David/Remote Stocks/album/People/res: 0.089s listing /Volumes/Public/David/Remote Stocks/.jalbum: 0.091s listing /Volumes/Public/David/Remote Stocks/Sports: 0.103s listing /Volumes/Public/David/Remote Stocks/Sports/.jalbum: 0.106s listing /Volumes/Public/David/Remote Stocks/Sports/.jalbum/thumbs: 0.108s listing /Volumes/Public/David/Remote Stocks/Scenic: 0.11s listing /Volumes/Public/David/Remote Stocks/Scenic/.jalbum: 0.122s listing /Volumes/Public/David/Remote Stocks/Scenic/.jalbum/thumbs: 0.124s listing /Volumes/Public/David/Remote Stocks/People: 0.126s listing /Volumes/Public/David/Remote Stocks/People/.jalbum: 0.133s
I finally attempted to perform a multi threaded listing on Windows to overcome network lag effects. It helped somewhat, -from 9 to 3 seconds, i.e 3 times faster, but still significantly slower performance than the 0.133s measured from my MacBook pro client.
Problem solved by using the Files.walkFileTree API. With it I'm able to grab all attributes of all files of a folder with one SAMBA network IO call.