基于camellia-redis-proxy的可插拔架构设计，支持对接外部kv存储（hbase、tikv、obkv），模拟redis协议
可以参考：article
- proxy基于伪redis-cluster模式运行，因此相同key会路由到同一个proxy节点
- proxy内部多work-thread运行，每个命令根据key哈希到同一个work-thread运行
- proxy本身弱状态
- proxy依赖的服务逻辑上包括：key-meta-server、sub-key-server
- key-meta-server，用于维护key的meta信息，包括key的类型、版本、ttl等
- sub-key-server，用于存储hash中的field等subkey
- 部分场景下（当前仅zset），可以在sub-key-server层，混合使用redis作为storage，更适合某些业务场景
- 对于hbase/tikv/obkv的访问有一个抽象层，也可以替换为其他kv存储
- 参考了 pika 、 kvrocks 、 tidis、 titan、 titea 的设计
- 使用gc机制来回收kv存储层的过期数据，具体见: gc
- 如何从kv数据结构映射到redis的复杂数据结构，具体见：key-encode
请参考：camellia-redis-proxy-bootstrap
具体见：kv-conf
| command | info |
|---|---|
| del | DEL key [key ...] |
| exists | EXISTS key [key ...] |
| expire | EXPIRE key seconds [NX | XX | GT | LT] |
| pexpire | PEXPIRE key milliseconds [NX | XX | GT | LT] |
| expireat | EXPIREAT key unix-time-seconds [NX | XX | GT | LT] |
| pexpireat | PEXPIREAT key unix-time-milliseconds [NX | XX | GT | LT] |
| unlink | UNLINK key [key ...] |
| type | TYPE key |
| ttl | TTL key |
| pttl | PTTL key |
| expiretime | EXPIRETIME key |
| pexpiretime | PEXPIRETIME key |
| scan | SCAN cursor [MATCH pattern] [COUNT count] [TYPE type] |
| hset | HSET key field value [field value ...] |
| hmset | HMSET key field value [field value ...] |
| hget | HGET key field |
| hmget | HMGET key field [field ...] |
| hdel | HDEL key field [field ...] |
| hgetall | HGETALL key |
| hlen | HLEN key |
| hkeys | HKEYS key |
| hvals | HVALS key |
| hexists | HEXISTS key field |
| hsetnx | HSETNX key field value |
| hstrlen | HSTRLEN key field |
| zadd | ZADD key score member [score member ...] |
| zcard | ZCARD key |
| zrange | ZRANGE key start stop [WITHSCORES] |
| zrangebyscore | ZRANGEBYSCORE key min max [WITHSCORES] [LIMIT offset count] |
| zrangebylex | ZRANGEBYLEX key min max [LIMIT offset count] |
| zrevrange | ZREVRANGE key start stop [WITHSCORES] |
| zrevrangebyscore | ZREVRANGEBYSCORE key min max [WITHSCORES] [LIMIT offset count] |
| zrevrangebylex | ZREVRANGEBYLEX key min max [LIMIT offset count] |
| zremrangebyrank | ZREMRANGEBYRANK key start stop |
| zremrangebyscore | ZREMRANGEBYSCORE key min max |
| zremrangebylex | ZREMRANGEBYLEX key min max |
| zrem | ZREM key member [member ...] |
| zscore | ZSCORE key member |
| zcount | ZCOUNT key min max |
| zlexcount | ZLEXCOUNT key min max |
| zrank | ZRANK key member [WITHSCORE] |
| zrevrank | ZREVRANK key member [WITHSCORE] |
| zmscore | ZMSCORE key member [member ...] |
| sadd | SADD key member [member ...] |
| smembers | SMEMBERS key |
| srem | SREM key member [member ...] |
| srandmember | SRANDMEMBER key [count] |
| spop | SPOP key [count] |
| sismember | SISMEMBER key member |
| smismember | SMISMEMBER key member [member ...] |
| scard | SCARD key |