Database Conflict Error Zope

order to try to avoid throwing away potentially computationally expensive transactions. The risk of harming data integrity should not be underestimated. Writing conflict resolution code takes some responsibility for transactional integrity away from the ZODB, and puts it in the hands of the developer writing the conflict resolution code. The current conflict resolution code is implemented with a storage mix-in found in ZODB/ConflictResolution.py. The idea's proposal, and an explanation of the interface, can be found here: http://www.zope.org/Members/jim/ZODB/ApplicationLevelConflictResolution Here is the most pertinent section, somewhat modified for this document's use: A new interface is proposed to allow object authors to provide a method for resolving conflicts. When a conflict is detected, then the database checks to see if the class of the object being saved defines the method, _p_resolveConflict. If the method is defined, then the method is called on the object. If the method succeeds, then the object change can be committed, otherwise a ConflictError is raised as usual. def _p_resolveConflict(oldState, savedState, newState): Return the state of the object after resolving different changes. Arguments: oldState The state of the object that the changes made by the current transaction were based on. The method is permitted to modify this value. savedState The state of the object that is currently stored in the database. This state was written after oldState and reflects changes made by a transaction that committed before the current transaction. The method is permitted to modify this value. newState The state after changes made by the current transaction. The method is not permitted to modify this value. This method should compute a new state by merging changes reflected in savedState and newState, relative to oldState. If the method cannot resolve the changes, th

by: [ date ] [ thread ] [ subject ] [ author ] Sudesh soni wrote at 2007-7-13 12:47 -0400: > ... >I am recieving following errors frequently as shown below: > >#1------------------------------------------------------------------------- > >Site Error >An error was encountered while publishing this resource. > >Error Type: ConflictError >Error Value: http://docs.zope.org/zope3/Code/ZODB/ConflictResolution.txt/index.html database conflict error (oid 0x09, class Products.Transience.Transience.Increaser, serial this txn started with 0x036ee0b224215066 2007-07-09 > >16:50:08.468000, serial currently committed 0x036ee0b39eeeeeee 2007-07-09 16:51:37.250000) This is a session conflict. Apparently, you have concurrent requests accessing the same session objects. While the "Increaser" implements application https://mail.zope.org/pipermail/zope/2007-July/171804.html specific conflict resolution, the "TemporaryStorage" often has not enough history to allow conflict resolution. >#2---------------------------------------------------------------------------- > >database conflict error (oid 0x7b61, class BTrees._OOBTree.OOBTree, serial this txn started with 0x036ee63aae219655 2007-07-10 16:26:40.812000, serial > >currently committed 0x036ee63b55aa87bb 2007-07-10 16:27:20.078000) This might also be a session related conflict: the relatively small "oid" may indicate this. If this is indeed the case, then Andreas' advice will not work. You can recognize this when the object retrieved by Andreas' proposal is something else than an "OOBTree". -- Dieter Previous message: [Zope] database conflict error Next message: [Zope] [TextIndexNG3] Extension modules now available as eggs Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] More information about the Zope mailing list

here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings http://stackoverflow.com/questions/22661373/zope-conflict-errors and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs http://plone.293351.n2.nabble.com/INFO-ZPublisher-Conflict-ConflictError-td7560269.html Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; database conflict it only takes a minute: Sign up Zope Conflict Errors up vote 0 down vote favorite My site's zope log reports a number of conflict errors. Average of 120 per day of which 2-3 are unresolved. I've come across many articles on why conflict errors occur but nothing has been clear. Most of these conflict errors occur on pages which database conflict error run select queries on MySQL database. It is said that the number of conflict errors rise with an increase in concurrency of http requests because one ZODB object is created and the other tries to write to it. (I could not understand why and how ZODB objects are modified. Can anyone explain this ?) But even when there is only one user using it, there are conflict errors raised. This generally happens when the website is accessed for the first time after an overnight restart of Zope. What I've noticed that during some instances, trying to load a page which involves running a select query against a table raises a conflict error if the table is modified at the same time because of some other activity on the website. All of this has to do with the ZODB object stuff. It should be storing the data from the table as an object or something. The original data is changed and hence the conflict. Am I correct ? The website uses Zope 2.12.19 with Zope's built-in session m

♦ ♦ | Report Content as Inappropriate ♦ ♦ INFO ZPublisher.Conflict ConflictError This post was updated on . Hi, I seem to regularly experience conflict errors which slow site responsiveness. See examples below. I'm currently modifying ploneCustom.css, but am no sure what might be causing this? System is in development mode. Cheers, Richard Plone 4.1.5 2012-10-16 19:19:51 INFO ZPublisher.Conflict ConflictError at /plone/sttr/rler: database conflict error (oid 0x0b, class Products.Transience.Transience.Increaser, serial this txn started with 0x0399f0a119d289aa 2012-10-16 12:17:06.052128, serial currently committed 0x0399f0a3d4fccb11 2012-10-16 12:19:49.918939) (2 conflicts (0 unresolved) since startup at Tue Oct 16 19:17:13 2012) 2012-10-16 19:57:33 INFO ZPublisher.Conflict ConflictError at /plone/news-events: database conflict error (oid 0x09, class Products.Transience.Transience.Length2, serial this txn started with 0x0399f0be4f665b33 2012-10-16 12:46:18.609335, serial currently committed 0x0399f0c8d9562833 2012-10-16 12:56:50.938254) (3 conflicts (0 unresolved) since startup at Tue Oct 16 19:17:13 2012) Nathan Van Gheem Reply | Threaded Open this post in threaded view ♦ ♦ | Report Content as Inappropriate ♦ ♦ Re: INFO ZPublisher.Conflict ConflictError How big is your site(how many objects)? What version of plone are you running?On Tue, Oct 16, 2012 at 8:02 AM, richardc <[hidden email]> wrote: Hi, I seem to regularly experience conflict errors which slow site responsiveness. See examples below. I'm currently modifying ploneCustom.css, but am no sure what might be causing this? Cheers, Richard 2012-10-16 19:19:51 INFO ZPublisher.Conflict ConflictError at /plone/sttr/rler: database conflict error (oid 0x0b, class Products.Transience.Transience.Increaser, serial this txn started with 0x0399f0a119d289aa 2012-10-16 12:17:06.052128, serial currently committed 0x0399f0a3d4fccb11 2012-10-16 12:19:49.918939) (2 conflicts (0 unresolved) since startup at Tue Oct 16 19:17:13 2012) 2012-10-16 19:57:33 INFO ZPublisher.Conflict ConflictError at /plone/news-events: database conflict error (oid 0x09, class Products.Transience.Transience.Length2, serial this txn started with 0x0399f0be4f665b33 2012-10-16 12:46:18.609335, serial currently committed 0x0399f0c8d9562833 2012-10-16 12:56:50.938254) (3 conflicts (0 unresolved) since startup at Tue Oct 16 19:17:13 2012) -- View this message in context: http://plone.293351.n2.nabble.com/INFO-Z