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 memcached+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
