[firebird-support] Re: Forced write
<< rddymanohar wrote: > We are on Firebird 1.56 and recently encountered database corruption > problem with a customer. Found that forced write was turned off on the > database and after the database was restored turned it on. However on > checking the next day forced write was again turned off. We do daily sweep, > reindex and backup on the database as maintenance at the the eod. Will any > of this cause forced write to be turned off. None of those operations, on their own, will change the forced write flag setting. The setting can be changed thru gfix command or API call. Sean P.S. A restore would not change the setting on its own -- it would restore using the setting that was present from the backup. >> Could it be that for Fb/1.5 any user can change this setting? If so, an impatient user might be tempted to increase performance... -- Aage J.
[firebird-support] Re: Forced write
We found it the ibo components was set to forced write no and that was causing the problem. Thanks --- In firebird-support@yahoogroups.com, Helen Borrie wrote: > > At 08:55 a.m. 18/07/2013, rddymanohar wrote: > >Hi, > >We are on Firebird 1.56 and recently encountered database corruption problem > >with a customer. Found that forced write was turned off on the database and > >after the database was restored turned it on. However on checking the next > >day forced write was again turned off. We do daily sweep, reindex and backup > >on the database as maintenance at the the eod. Will any of this cause forced > >write to be turned off. > > None of the above will change the Forced Write setting. However, in the very > ancient version of Firebird that you are using, a client can do it, via the > connection API. The very first thing I would recommend is to examine closely > the connection settings on all client applications. > > A common source of this problem is Delphi applications that provide > properties and/or arrays of properties in the connection component > (connection alone, or database component). If this is your case, look at > *both* the property in question (ForcedWrites TRUE/FALSE) and *also* the > Params property of the connection/database component. > > > Helen Borrie, Support Consultant, IBPhoenix (Pacific) > Author of "The Firebird Book" and "The Firebird Book Second Edition" > http://www.firebird-books.net > __ >
Re: [firebird-support] Re: Forced write
> We found it the ibo components was set to forced write no and that was > causing the problem. What is the IBO version you are using? -- With regards, Thomas Steinmaurer http://www.upscene.com/ Professional Tools and Services for Firebird FB TraceManager, IB LogManager, Database Health Check, Tuning etc.
[firebird-support] Re: Forced write, page size and buffer size
18.08.2014 22:51, Aldo Caruso wrote: > > For reliability reasons, I decided to turn on forced writes on a > database running on Linux. What is FB architecture: SS / CS / SC? I suspect SS given your default cache size (2048 pages) but it's worth double checking. > 1) Does it makes sense to activate forced writes on Linux ? It depends on what reliability means to you. > 2) Is increasing the page size the right approach to improve performance > ? Which are the drawbacks of setting page size to 16K ? The cost is a higher concurrency for the same pages under parallel load. > 3) The same question stands for cache pages: is it useful ( or has > disadvantages ) to have so many cache pages as there are on disk pages ( > provided there is enough RAM size ) ? It would surely not hurt. Dmitry ++ Visit http://www.firebirdsql.org and click the Documentation item on the main (top) menu. Try FAQ and other links from the left-side menu there. Also search the knowledgebases at http://www.ibphoenix.com/resources/documents/ ++ Yahoo Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/firebird-support/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/firebird-support/join (Yahoo! ID required) <*> To change settings via email: firebird-support-dig...@yahoogroups.com firebird-support-fullfeatu...@yahoogroups.com <*> To unsubscribe from this group, send an email to: firebird-support-unsubscr...@yahoogroups.com <*> Your use of Yahoo Groups is subject to: https://info.yahoo.com/legal/us/yahoo/utos/terms/
Re: [firebird-support] Re: Forced write, page size and buffer size
Dmitry, Your guess is correct: Super Server architecture. Reliability in this context means for me having no database corruption after a power failure or kernel panic. Aldo Caruso El 19/08/14 a las 06:12, Dmitry Yemanov dim...@users.sourceforge.net [firebird-support] escibió: > 18.08.2014 22:51, Aldo Caruso wrote: >> For reliability reasons, I decided to turn on forced writes on a >> database running on Linux. > What is FB architecture: SS / CS / SC? I suspect SS given your default > cache size (2048 pages) but it's worth double checking. > >> 1) Does it makes sense to activate forced writes on Linux ? > It depends on what reliability means to you. > >> 2) Is increasing the page size the right approach to improve performance >> ? Which are the drawbacks of setting page size to 16K ? > The cost is a higher concurrency for the same pages under parallel load. > >> 3) The same question stands for cache pages: is it useful ( or has >> disadvantages ) to have so many cache pages as there are on disk pages ( >> provided there is enough RAM size ) ? > It would surely not hurt. > > > Dmitry > > > > > > > > > > ++ > > Visit http://www.firebirdsql.org and click the Documentation item > on the main (top) menu. Try FAQ and other links from the left-side menu > there. > > Also search the knowledgebases at > http://www.ibphoenix.com/resources/documents/ > > ++ > > > Yahoo Groups Links > > > ++ Visit http://www.firebirdsql.org and click the Documentation item on the main (top) menu. Try FAQ and other links from the left-side menu there. Also search the knowledgebases at http://www.ibphoenix.com/resources/documents/ ++ Yahoo Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/firebird-support/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/firebird-support/join (Yahoo! ID required) <*> To change settings via email: firebird-support-dig...@yahoogroups.com firebird-support-fullfeatu...@yahoogroups.com <*> To unsubscribe from this group, send an email to: firebird-support-unsubscr...@yahoogroups.com <*> Your use of Yahoo Groups is subject to: https://info.yahoo.com/legal/us/yahoo/utos/terms/
