Memcache Avalanche Phenomenon

Defined:

Cache avalanche phenomenon is due to a cache node failure (or cache failure), causing other nodes cache hit rate drop, cache missing data to database query, a short time caused the database server crashes, restart after a short period of time and crash, but at this time the cache more, after a period, the database gradually stabilized. Workaround:

Analyze user behavior and try to distribute the failure time points evenly. Control the number of database connections, concurrency reduced by two cache, A1 as the original cache, A2 as a copy cache, when A1 fails, can access A2