We are developing an application, where users can vote for many objects. (for example, voting the best music video of the week)
- This means, we have millions of possible objects to vote for, and millions of users To our best knowledge, after taking in consideration different options, the best (or the only) voting system is: Memcache+Bulk DB write in DB - If number of objects in Memcache will achieve a specified limit (for example 3000) then write in DB. The writing speed into DB is about 100/sec. This also means, if we would set the above mentioned 3000 objects, the writing would last for 30 sec... The problem; during save in DB, voting must be blocked. In other words, if from many millions of objects, there are 3000 achieved voted objects, we need to write it into DB and it can happen too many times, and blocking the whole voting mechanism. If we do not block the voting whilst writing in DB, the result could be wrong number of votes from cache (see Workflow: step 3). Workflow: 1. vote received 2. find object in memcache 3. if not found in memcache get from DB and put it in 4. increment the number of votes of the object in memcache 5. check object number in memcache 6. if necessary, save in DB and empty memcache ... -- You received this message because you are subscribed to the Google Groups "Google App Engine for Java" group. To post to this group, send email to google-appengine-java@googlegroups.com. To unsubscribe from this group, send email to google-appengine-java+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-appengine-java?hl=en.
