-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Chris Withers wrote: > +1 from me too, this feels like a really good proposal :-)
+1. Sessions might be a good example of a storage using 'fsync-behavior=None': you would get the speedup, and the ability to survive a restart, without needing to treat the data as "precious". > Jim Fulton wrote: >> +1 >> >> Lennart Regebro wrote: >>> On 10/11/06, Roché Compaan <[EMAIL PROTECTED]> wrote: >>>> http://mail.zope.org/pipermail/zodb-dev/2004-July/007682.html >>> >>> I read this thread, and it seems to me that the ultimate solution >>> would be to have a setting for FSStorage, say "fsync-behaviour" with >>> the options of "single", "double", "none" or "interval". We'd need an >>> explaining text too. Something like: >>> >>> fsync-behaviour: Determines when fsync is called. Default: single. >>> >>> Options: >>> >>> Single: Calls fsync once per transaction. Gives you reasonable data >>> reliability in most cases. You should in a crash only lose one >>> transaction. >>> >>> Double: Calls fsync before marking transaction as complete as well as >>> after marking it as complete. This setting is only useful if you have >>> configured the complete storage chain (operating system, filesystem, >>> drivers, controllers and disks) will not let fsync return until data >>> is safely and completely written to disk. In most cases and without >>> configuration of the complete storage chain, this setting will slow >>> down FSStorage without actually increasing the reliability of data >>> written to disk. >>> >>> Interval: Will call fsync only every couple of transactions, with the >>> interval determined by the setting "fsync-interval". This is good for >>> write-intensive applications where you don't mind loosing a couple of >>> transactions if the computer should crash. >>> >>> None: Will never call fsync. Good for applications of high write load >>> where the data is not critical. Never ever use this setting on >>> windows, as it on windows makes it highly likely that data will not be >>> written to disk at all, and a crash could quite likely make you loose >>> all your changes. >>> >> >> > - -- =================================================================== Tres Seaver +1 202-558-7113 [EMAIL PROTECTED] Palladion Software "Excellence by Design" http://palladion.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFFLq00+gerLs4ltQ4RAgIPAJ9sX4MoQ/slgP2C8UvONdpobBuuewCghisA cylxDrhhyNFd1WDOjgtRsi4= =JmrL -----END PGP SIGNATURE----- _______________________________________________ For more information about ZODB, see the ZODB Wiki: http://www.zope.org/Wikis/ZODB/ ZODB-Dev mailing list - ZODB-Dev@zope.org http://mail.zope.org/mailman/listinfo/zodb-dev