How to decompress faster in Java?

Our system is ha开发者_Python百科ving a problem with too much files, which is used in a webapp which should be using all the time. That mean the files cannot be deleted and there are too much of them, making the system(which is a windows) slow. We would like zip up the files, and when the file is request, we unzip the particular file out.

I've try the java ZipFile class, and the performance is not good enough, because there will be many people using the webapp and they will request the files. From my observation, the unzipping action require time between 0.5 secs to 2 secs, and when there are too much user, the system cannot catch up to them.

For example, I've use a Jmeter to simulate a situation where 30 user use the system, with a random delay between 0.3 secs to 0.6 secs. Although I doubt there may not be so much requests, I cannot know for advance that how many people will use the webapps. I would like to ask you guys, is there any other method to solve this problem?

Thanks in advance!!

P.S. If any 3rd party library is need, it must be free!

P.S. Because the number of files is just too much, and it hang the machine. We would like do this : zip up 2000 file into a zip file, then the number of files will decrease and hope the system won't hang anymore, and when need, we unzip some file out.

Okay, here's some thoughts. It appears to me that your core problem is the slowness of your system and that you're trying to fix it by compressing the files and decompressing them on demand. Then you've found that the decompression is too slow and you need a faster way to do that.

Now I'm not entirely certain why you think this compression will speed things up instead of making things slower.

I would go back to the original problem and work more on solving that. Why is the number of files making your system slow? If you can figure that out, you can fix it in a way that doesn't involve things going even slower.

If it's an issue with too many files in a directory, think about splitting into multiple directories. But I have no idea whether NTFS even has that problem (FAT did). For example, if you have a directory with files for every minute of the last ten years (five million files), you can split them into day directories (three and a half thousand directories with fifteen hundred files in each).

Compression won't reduce the number of files, just the space taken by them.

If it's an issue with the number of files on the system (rather than in a directory), there are plenty of ways to split files between systems as well. Example, hive off 10% of the entire file set to ten different machines and forward incoming requests for a specific file to the relevant machine.

But, I have to say, I've seen Windows machines handle absolute bucket-loads of files so I'd be very surprised if the problem lay there. I think you're probably just going to have to track down what's actually causing your "hangs".

compressing/uncompressing the files will not make the windows faster.

If zip doesn't provides performance gain (despite has native implementation in Java), you can try to improve at the filesystem-level. Folders with too many (>10000) files doesn't work well under some Windows filesystems, so try to divide the files into several folders, tune the NTFS filesystem (cluster size, reserved space for filesystem), disable anti virus, disable indexing, buy an SSD SLC hard disk...