MODE Z technology

[phoenixfr]

seen that on raidenftpd's page.
don't know if this is off any interest , talking about performances.

maybe it can make listing faster or transferring not compressed files.

sounds good to me since lots of clients start supporting it. in addition there is an rfc describing it.

maybe this can be used on a file-extension basis to save cpu time (compressing all the data could be a waste of time). meaning it would on-the-fly compress a .log file and wouldn't compress a rar/zip file.


links :
http://www.raidenftpd.com/en/features.html
http://community.roxen.com/developers/idocs/drafts/draft-preston-ftpext-deflate-02.html


Please do not hesitate to comment on that technology.

[Mouton]

u can see dark comment about that there:
http://forum.flashfxp.com/showthread.php?s=&threadid=4430

[Zer0Racer]

darkone commented this technology in flashfxp forums not long ago. http://forum.flashfxp.com/showthread.php?s=&threadid=4430

My guess: it won't be implemtented in ioFTPD.

Originally posted by dark0n3
It's all about how you define world 'real'. Mode Z has it's advantages on small not so busy server, with enough cpu-power to take advantage of whole bandwidth with the compression. On large servers it will degrade performance, if compressed output is not cached. (building cache from stream, isn't easiests tasks to do ;)) My own biased opinion is that lifetime of 'Mode Z' will be comparable to what diskcompression utilities had, perhaps even shorter. As usual this approach was developed by unix people, who know nothing about scalability :) (sorry, but that's the way it is... apache2, has been in developement for years, and they still not haven't got a stable release :\)

Summa summarum:
- Increases network efficiency on files that can be compressed. Decreases efficiency on certain files.
- Adds latency in 'not so well programmed' implementations
- Increases transfer cpu-usage by hundreds of percentages
- Adds memory bandwidth usage (buffer copying)
- Not usable on gbit networks, if server is to take advantage of full bandwidth
- Works very well on 100mbit and slower connections with 'properly' coded daemon and client implementation. (read(), zip(), send() is not such... :])
- For best efficiency requires more than one CPU... (in well coded application :))

.... but then again, what do I know :)

[Zer0Racer]

Mouton, stop picking my brain plz mmkay ;)