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

[Shane Hathaway]

Jeremy Hylton wrote:
> On Thu, 2003-06-12 at 05:27, Chris Withers wrote:
> 
>>Hi,
>>
>>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
> 
> 
> I don't know where this error message comes from, but I'll mention that
> read conflicts are a bit different than write conflicts.  In particular,
> if a transaction gets a read conflict before it modifies any objects,
> then aborting the transaction and trying again won't help.

AFAICT this applies only to applications other than Zope.  When Zope 
retries a request (after getting a conflict), it closes the connection 
and opens a new one.  On opening a new connection, the cache will be 
updated and the attempt may succeed.  Correct me if I'm wrong.

Shane