关于Redis的复制 partitial resync

Redis本身的复制是不稳定的，当slave超时后会执行一次resync，会导致master即使在未开持久化的情况下执行bgsave，并将snapshot发送到slave后建立复制流；那么在这种情况下比较推荐的拓扑就是链式复制，而不是一对多，否则当网络环境抖动时会对master产生很大的负载以及网卡压力；

Redis关于partitial resync还在测试当中，据说2.8会release，不会按照MySQL binlog的那种方式:

MySQL is one of the first databases I get exposed for sure, a few decades ago, and the first time I had to setup replication I was shocked about how much it sucked. Are you serious that I need to enable binary logs and deal with offset?

Redis replication, that everyone agrees is dead-simple tosetup, is more or less a response to how much I dislike MySQL replication fromthe point of view of the "user interface".

Even if we needed partial replicaton, I didn't wantedRedis to be like that.

（据说新浪改写了redis的replication，产用类似MySQL的方式：P）；

具体细节参考Redis的作者blog:

Design:http://antirez.com/news/31

http://antirez.com/news/45

PSYNC: http://antirez.com/news/47