Thanks, Abinesh I've read the paper you recommended, it's very helpful.
Best Regards, Steve On Thursday, March 14, 2013 2:56:43 PM UTC+8, abinesh td wrote: > Hi Steve, > > Here are a few techniques that solve this problem: > > 1. Gumball technique developed at USC > - > > http://abineshtd.blogspot.com/2012/09/gumball-race-condition-prevention.html > - http://dblab.usc.edu/Users/papers/GumballTR.pdf > 2. A solution in McDipper developed at Facebook > - > > https://www.facebook.com/notes/facebook-engineering/mcdipper-a-key-value-cache-for-flash-storage/10151347090423920 > > Thanks > Abinesh > > > > On Thursday, February 28, 2013 1:06:43 AM UTC-8, biao zhang wrote: >> >> Hi, everyone >> >> I found a question on Stack Overflow which is about race condition which >> is not easy to solve: >> >> http://stackoverflow.com/questions/7802772/cache-consistency-when-using-memcached-and-a-rdbms-like-mysql >> >> the question is: >> >> I have taken a database class this semester and we are studying about >> maintaining cache consistency between the RDBMS and a cache server such as >> memcached. The consistency issues arise when there are race conditions. For >> example: 1. Suppose I do a get(key) from the cache and their is a cache >> miss. Because I get a cache miss, I fetch the data from the database, and >> then do a put(key,value) into the cache. 2. But, a race condition might >> happen, where some other user might delete the data I fetched from the >> database. This delete might happen before I do a put into the cache. >> >> Thus, ideally the put into the cache should not happen, since the data is >> longer present into the database. >> >> If the cache entry has a TTL, the entry in the cache might expire. But >> still, their is a window where the data in the cache is inconsistent with >> the database. >> >> >> Does anyone know how to prevent race condition in that scenario? >> >> Thanks in advance. >> >> Best Regards, >> >> Steve >> >> >> >> >> -- --- You received this message because you are subscribed to the Google Groups "memcached" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
