[Zope3-Users] Ahh, counters... Best practice?

[Max M]

Benji York skrev:
 > Jeff Shell wrote:
 >> We're working on something where we need to allow site visitors to
 >> rate items. It's the basic star-rating thing. We want to keep a count
 >> of the number of votes along with the current value.
 >
 > At work we've been contemplating an approach for use in some similar
 > situations we want to address.
 >
 > In broad strokes: keep the updated value in memory, write the value to
 > the database "periodically" (for whatever value of "periodically" is
 > appropriate for the data).
 >
 > This should work well when the value changes often and loosing the most
 > recent updates to the value isn't catastrophic.


I have used this approach in mxmcounter for zope 2. It keeps a dict in 
memory, by making it a module attribute.

Every n count it then writes the dict to disk. It has worked on my site 
for years with no problems.

Only a single problem has been reported by another user. Apparently a 
zope site crashed while writing the dict, and so left it unreadable.

After restoring the dict on file from backup the site ran fine again.


-- 

hilsen/regards Max M, Denmark

http://www.mxm.dk/
IT's Mad Science

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