Setup: Zope 2.7.0 Python 2.3.3 Linux2 CMF 1.4.4 Problem Area: ZPT which contains a call to a ZPT macro The ZPT macro gets data from a parsed RSS feed Now using CMFSin 0.6.1 Previously used RDFSummary 2.4 Symptom: When a new item is added to the RSS feed (b/c a news item was published), my ZPT displays the RSS data inconsistently with each browser refresh -- sometimes the new item appears, sometimes not. At first I thought this was a problem with the RDFSummary product, but I have the same issue with CMFSin. Finally, I at least discovered something that "fixes" the problem: flushing the ZODB cache. Obviously, I don't want to flush the ZODB cache every time my news feed is updated. Is this a known problem that has been resolved in later versions of Zope 2.7/CMF? Since it's not technically an error, I don't have a traceback. Thanks for any help, David
David Chandek-Stark wrote at 2005-5-12 10:49 -0400:
... Previously used RDFSummary 2.4
Symptom: When a new item is added to the RSS feed (b/c a news item was published), my ZPT displays the RSS data inconsistently with each browser refresh -- sometimes the new item appears, sometimes not.
A bug in "RDFSummary" which uses a ZODB cache to maintain the fetched items. Unfortunately, each connection has its own independent ZODB cache.... Using a ZODB cache for this use case is both inefficient and error prone. You should contact the "RDFSummary" authors. -- Dieter
Dieter Maurer wrote:
Symptom: When a new item is added to the RSS feed (b/c a news item was published), my ZPT displays the RSS data inconsistently with each browser refresh -- sometimes the new item appears, sometimes not.
A bug in "RDFSummary" which uses a ZODB cache to maintain the fetched items. Unfortunately, each connection has its own independent ZODB cache....
Using a ZODB cache for this use case is both inefficient and error prone.
You should contact the "RDFSummary" authors.
As mentioned in the original post, I am now using CMFSin and having the smae problem. Are you saying that this is an issue with the design of the product? Thanks, David
David Chandek-Stark wrote at 2005-5-12 15:31 -0400:
Dieter Maurer wrote:
Symptom: When a new item is added to the RSS feed (b/c a news item was published), my ZPT displays the RSS data inconsistently with each browser refresh -- sometimes the new item appears, sometimes not.
A bug in "RDFSummary" which uses a ZODB cache to maintain the fetched items. Unfortunately, each connection has its own independent ZODB cache....
Using a ZODB cache for this use case is both inefficient and error prone.
You should contact the "RDFSummary" authors.
As mentioned in the original post, I am now using CMFSin and having the smae problem. Are you saying that this is an issue with the design of the product?
I am saying what I said: "RDFSummary" caches with "_v_" variables i.e. it uses a ZODB cache and ZODB caches are difficult to synchronize between workers. This easily leads to such inconsistencies as you have described them. Other products may make the same error. I do not know "CMFSin". Therefore, I cannot tell you that it does. But, it you see what you had described, there is a not so small chance ... -- Dieter
participants (2)
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David Chandek-Stark -
Dieter Maurer