Re: [ZODB-Dev] Re: Anybody using ZODB with no calls to fsync in production?
David Binger wrote: This is an interesting point, and it makes me wonder if there would be interest having the fsync behavior vary on a per-transaction basis instead of a per-storage basis. Maybe the client submitting transactions that are just Session-like changes could include a message to the server indicating that this transaction is not precious. Nah, too subtle/fragile/complicated... ...that's my gut feel anyway. I really like the proposal as it stands though :-) Chris -- Simplistix - Content Management, Zope Python Consulting - http://www.simplistix.co.uk ___ 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
Re: [ZODB-Dev] Re: Anybody using ZODB with no calls to fsync in production?
Chris Withers wrote: David Binger wrote: This is an interesting point, and it makes me wonder if there would be interest having the fsync behavior vary on a per-transaction basis instead of a per-storage basis. Maybe the client submitting transactions that are just Session-like changes could include a message to the server indicating that this transaction is not precious. Nah, too subtle/fragile/complicated... ...that's my gut feel anyway. I really like the proposal as it stands though :-) Agreed. Jim -- Jim Fulton mailto:[EMAIL PROTECTED] Python Powered! CTO (540) 361-1714http://www.python.org Zope Corporation http://www.zope.com http://www.zope.org ___ 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
Re: [ZODB-Dev] Re: Anybody using ZODB with no calls to fsync in production?
OK, cool. Anybody feel like implementing it? I might, but I will not have time before february, and people who know the ZODB.code already will probably make a faster and better job. -- Lennart Regebro, Nuxeo http://www.nuxeo.com/ CPS Content Management http://www.nuxeo.org/ ___ 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
Re: [ZODB-Dev] Re: Anybody using ZODB with no calls to fsync in production?
Hi, Lennart Regebro wrote: OK, cool. Anybody feel like implementing it? I might, but I will not have time before february, and people who know the ZODB.code already will probably make a faster and better job. Can you put it on line in some wiki? Maybe I have some time before February. ;) Christian -- gocept gmbh co. kg - forsterstraße 29 - 06112 halle/saale - germany www.gocept.com - [EMAIL PROTECTED] - phone +49 345 122 9889 7 - fax +49 345 122 9889 1 - zope and plone consulting and development signature.asc Description: OpenPGP digital 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
Re: [ZODB-Dev] Re: Anybody using ZODB with no calls to fsync in production?
Christian Theune wrote: Hi, Lennart Regebro wrote: OK, cool. Anybody feel like implementing it? I might, but I will not have time before february, and people who know the ZODB.code already will probably make a faster and better job. Can you put it on line in some wiki? Specifically: http://www.zope.org/Wikis/ZODB/FrontPage Jim -- Jim Fulton mailto:[EMAIL PROTECTED] Python Powered! CTO (540) 361-1714http://www.python.org Zope Corporation http://www.zope.com http://www.zope.org ___ 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
[ZODB-Dev] Re: Anybody using ZODB with no calls to fsync in production?
-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 Designhttp://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
