Redis内存溢出时都发生什么了？

原文地址：http://redis.io/topics/faq#what-happens-if-redis-runs-out-of-memory

What happens if Redis runs out of memory?

Redis will either be killed by the Linux kernel OOM killer, crash with an error, or will start to slow down. With modern operating systems malloc() returning NULL is not common, usually the server will start swapping, and Redis performance will degrade, so you'll probably notice there is something wrong.

The INFO command will report the amount of memory Redis is using so you can write scripts that monitor your Redis servers checking for critical conditions.

Redis has built-in protections allowing the user to set a max limit to memory usage, using the maxmemory option in the config file to put a limit to the memory Redis can use. If this limit is reached Redis will start to reply with an error to write commands (but will continue to accept read-only commands), or you can configure it to evict keys when the max memory limit is reached in the case you are using Redis for caching.

We have documentation if you plan to use Redis as an LRU cache.