[ZODB-Dev] My turn for ReadConflictErrors...

Dieter Maurer dieter at handshake.de
Fri Jun 13 23:02:32 EDT 2003


Chris Withers wrote at 2003-6-12 10:27 +0100:
 > I added a 'Recent Postings' box to the right of http://www.bay-c.co.uk.
 > It's basically a ZCatalog search sorted on date of the contents of a Squishdot 
 > Site done in a Python Script and presented through a ZPT.
 > 
 > However, I'm now starting to see these:
 > 
 > Error Value: ZODB.POSException.ReadConflictError on database read conflict error 
 > (oid 000000000001dee1, class BTrees.IOBTree.IOBucket) in 
 > "standard:'here/recent_helper'", at line 2, column 1

You know my "No more ReadConflicts" patch?

  <http://www.dieter.handshake.de/pyprojects/zope>


For us, it removed all database read conflicts.


For Zope 2.6.2 (and above), it will probably be unable to prevent
"ReadConflictError"s resulting from session access (because
ChrisM no longer uses a "LowConflictConnection" for session
handling). As we use a session implementation the administrative
data of which is not sensitive to inconsistencies, we will
probably return to the pre-Zope 2.6.2 "LowConflictConnection"
use.


 > Notably when I'm in the process of writing or moderating postings.

I think the patch will help you. Our read conflict errors were also
caused by catalog writes and concurrent catalog reads.


Dieter



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