[Zope-CMF] CMF write performance as poor as Plone?

[Tres Seaver]

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Ross Patterson wrote:
> Tres Seaver <tseaver at palladion.com> writes:
> 
>> Andreas Jung wrote:
>>> On 23.11.2008 11:57 Uhr, Charlie Clark wrote:
>>>> Am 23.11.2008 um 09:24 schrieb Andreas Jung:
>>>>
>>>>> This issue is independent of the client-side. ab2 and cmf/plone were
>>>>> running on the same (fast) machine.
>>>> Is this really content that is suited for the ZODB?
>>>
>>> I am talking of the standard content-types that are available in CMF and 
>>> Plone like Document, News etc.
>> Are you trying to proceess feed content, one document per request?  You
>> should be batching up that content, to get better amortization of the
>> indexing overhead.
>>
>> You should also be checking for conflict errors:  they would result in a
>> *large* performance hit.
> 
> Quick question.  How much of the write concurrency problem comes from
> the fact that the ZPublisher retries the entire *request* on
> WriteConflict instead of just trying to committing the transaction
> again?

It can't retry the commit:  the point is that the conflict can't be
resolved using the values read from the database at the start of the
transaction.  We have to redo the whole request, re-reading any objects
in the context of a new transaction;  otherwise, we would be back to
"last write wins", which is a lose.


Tres.
- --
===================================================================
Tres Seaver          +1 540-429-0999          tseaver at palladion.com
Palladion Software   "Excellence by Design"    http://palladion.com
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