twemproxy（发音为“two-em-proxy”），又名胡桃夹子，
是memcached和redis协议的快速轻量级代理。
它主要是为了减少与后端缓存服务器的连接数量。
这与协议管道和切分一起，使您能够水平扩展分布式缓存体系结构。

Redis Command Support

Keys Command

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|        DEL        |    Yes     | DEL key [key …]                                                                                                     |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       DUMP        |    Yes     | DUMP key                                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      EXISTS       |    Yes     | EXISTS key                                                                                                          |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      EXPIRE       |    Yes     | EXPIRE key seconds                                                                                                  |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     EXPIREAT      |    Yes     | EXPIREAT key timestamp                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       KEYS        |    No      | KEYS pattern                                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      MIGRATE      |    No      | MIGRATE host port key destination-db timeout                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       MOVE        |    No      | MOVE key db                                                                                                         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      OBJECT       |    No      | OBJECT subcommand [arguments [arguments …]]                                                                         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      PERSIST      |    Yes     | PERSIST key                                                                                                         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      PEXPIRE      |    Yes     | PEXPIRE key milliseconds                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     PEXPIREAT     |    Yes     | PEXPIREAT key milliseconds-timestamp                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      PTTL         |    Yes     | PTTL key                                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     RANDOMKEY     |    No      | RANDOMKEY                                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      RENAME       |    No      | RENAME key newkey                                                                                                   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     RENAMENX      |    No      | RENAMENX key newkey                                                                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      RESTORE      |    Yes     | RESTORE key ttl serialized-value                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      SORT         |    Yes     | SORT key [BY pattern] [LIMIT offset count] [GET pattern [GET pattern ...]] [ASC|DESC] [ALPHA] [STORE destination]   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       TTL         |    Yes     | TTL key                                                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      TYPE         |    Yes     | TYPE key                                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      SCAN         |    No      | SCAN cursor [MATCH pattern] [COUNT count]                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+

Strings Command

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      APPEND       |    Yes     | APPEND key value                                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     BITCOUNT      |    Yes     | BITCOUNT key [start end]                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     BITFIELD      |    Yes     | BITFIELD key [GET] [SET] [INCRBY] [WRAP|SAT|FAIL]                                                                   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       BITOP       |    No      | BITOP operation destkey key [key …]                                                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      BITPOS       |    Yes     | BITPOS key bit [start] [end]                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       DECR        |    Yes     | DECR key                                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      DECRBY       |    Yes     | DECRBY key decrement                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|        GET        |    Yes     | GET key                                                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      GETBIT       |    Yes     | GETBIT key offset                                                                                                   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      GETDEL       |    Yes     | GETDEL key                                                                                                          |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       GETEX       |    Yes     | GETEX key [EX seconds|PX milliseconds|EXAT timestamp|PXAT milliseconds-timestamp|PERSIST]                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     GETRANGE      |    Yes     | GETRANGE key start end                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      GETSET       |    Yes     | GETSET key value                                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       INCR        |    Yes     | INCR key                                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      INCRBY       |    Yes     | INCRBY key increment                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    INCRBYFLOAT    |    Yes     | INCRBYFLOAT key increment                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       MGET        |    Yes     | MGET key [key …]                                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       MSET        |    Yes     | MSET key value [key value …]                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      MSETNX       |    No      | MSETNX key value [key value …]                                                                                      |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      PSETEX       |    Yes     | PSETEX key milliseconds value                                                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|        SET        |    Yes     | SET key value [EX seconds|PX milliseconds|EXAT timestamp|PXAT milliseconds-timestamp|KEEPTTL] [NX|XX] [GET]         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      SETBIT       |    Yes     | SETBIT key offset value                                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       SETEX       |    Yes     | SETEX key seconds value                                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       SETNX       |    Yes     | SETNX key value                                                                                                     |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     SETRANGE      |    Yes     | SETRANGE key offset value                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      STRALGO      |    No      | STRALGO LCS algo-specific-argument [algo-specific-argument …]                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      STRLEN       |    Yes     | STRLEN key                                                                                                          |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
  • MSET support is not Atomic

Hashes

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       HDEL        |    Yes     | HDEL key field [field ...]                                                                                          |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HEXISTS      |    Yes     | HEXISTS key field                                                                                                   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       HGET        |    Yes     | HGET key field                                                                                                      |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HGETALL      |    Yes     | HGETALL key                                                                                                         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HINCRBY      |    Yes     | HINCRBY key field increment                                                                                         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    HINCRBYFLOAT   |    Yes     | HINCRBYFLOAT key field increment                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HKEYS        |    Yes     | HKEYS key                                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HLEN         |    Yes     | HLEN key                                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HMGET        |    Yes     | HMGET key field [field ...]                                                                                         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HMSET        |    Yes     | HMSET key field value [field value ...]                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HSET         |    Yes     | HSET key field value                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HSETNX       |    Yes     | HSETNX key field value                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HVALS        |    Yes     | HVALS key                                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      HSCAN        |    Yes     | HSCAN key cursor [MATCH pattern] [COUNT count]                                                                      |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+

Lists

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      BLMOVE       |    No      | BLMOVE source destination LEFT|RIGHT LEFT|RIGHT timeout                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       BLPOP       |    No      | BLPOP key [key …] timeout                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       BRPOP       |    No      | BRPOP key [key …] timeout                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    BRPOPLPUSH     |    No      | BRPOPLPUSH source destination timeout                                                                               |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      LINDEX       |    Yes     | LINDEX key index                                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      LINSERT      |    Yes     | LINSERT key BEFORE|AFTER pivot element                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       LLEN        |    Yes     | LLEN key                                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       LMOVE       |    Yes     | LMOVE source destination LEFT|RIGHT LEFT|RIGHT                                                                      |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       LPOP        |    Yes     | LPOP key [count]                                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       LPOS        |    Yes     | LPOS key element [RANK] [COUNT] [MAXLEN]                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       LPUSH       |    Yes     | LPUSH key element [element …]                                                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      LPUSHX       |    Yes     | LPUSHX key element [element …]                                                                                      |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      LRANGE       |    Yes     | LRANGE key start stop                                                                                               |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       LREM        |    Yes     | LREM key count element                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       LSET        |    Yes     | LSET key index element                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       LTRIM       |    Yes     | LTRIM key start stop                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       RPOP        |    Yes     | RPOP key [count]                                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     RPOPLPUSH     |    Yes*    | RPOPLPUSH source destination                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       RPUSH       |    Yes     | RPUSH key element [element …]                                                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      RPUSHX       |    Yes     | RPUSHX key element [element …]                                                                                      |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
  • RPOPLPUSH support requires that source and destination keys hash to the same server. You can ensure this by using the same hashtag for source and destination key. Twemproxy does no checking on its end to verify that source and destination key hash to the same server, and the RPOPLPUSH command is forwarded to the server that the source key hashes to

Sets

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       SADD        |    Yes     | SADD key member [member …]                                                                                          |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       SCARD       |    Yes     | SCARD key                                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       SDIFF       |    Yes*    | SDIFF key [key …]                                                                                                   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    SDIFFSTORE     |    Yes*    | SDIFFSTORE destination key [key …]                                                                                  |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      SINTER       |    Yes*    | SINTER key [key …]                                                                                                  |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    SINTERSTORE    |    Yes*    | SINTERSTORE destination key [key …]                                                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     SISMEMBER     |    Yes     | SISMEMBER key member                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     SMEMBERS      |    Yes     | SMEMBERS key                                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    SMISMEMBER     |    Yes     | SMISMEMBER key member [member …]                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       SMOVE       |    Yes*    | SMOVE source destination member                                                                                     |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       SPOP        |    Yes     | SPOP key [count]                                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    SRANDMEMBER    |    Yes     | SRANDMEMBER key [count]                                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       SREM        |    Yes     | SREM key member [member …]                                                                                          |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       SSCAN       |    Yes     | SSCAN key cursor [MATCH] [COUNT]                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      SUNION       |    Yes*    | SUNION key [key …]                                                                                                  |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    SUNIONSTORE    |    Yes*    | SUNIONSTORE destination key [key …]                                                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
  • SIDFF, SDIFFSTORE, SINTER, SINTERSTORE, SMOVE, SUNION and SUNIONSTORE support requires that the supplied keys hash to the same server. You can ensure this by using the same hashtag for all keys in the command. Twemproxy does no checking on its end to verify that all the keys hash to the same server, and the given command is forwarded to the server that the first key hashes to.

Sorted Sets

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     BZPOPMAX      |    No      | BZPOPMAX key [key …] timeout                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     BZPOPMIN      |    No      | BZPOPMIN key [key …] timeout                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       ZADD        |    Yes     | ZADD key [NX|XX] [GT|LT] [CH] [INCR] score member [score member …]                                                  |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       ZCARD       |    Yes     | ZCARD key                                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      ZCOUNT       |    Yes     | ZCOUNT key min max                                                                                                  |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       ZDIFF       |    Yes*    | ZDIFF numkeys key [key …] [WITHSCORES]                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    ZDIFFSTORE     |    Yes*    | ZDIFFSTORE destination numkeys key [key …]                                                                          |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      ZINCRBY      |    Yes     | ZINCRBY key increment member                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      ZINTER       |    Yes*    | ZINTER numkeys key [key …] [WEIGHTS] [SUM|MIN|MAX] [WITHSCORES]                                                     |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    ZINTERSTORE    |    Yes*    | ZINTERSTORE destination numkeys key [key …] [WEIGHTS] [SUM|MIN|MAX]                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     ZLEXCOUNT     |    Yes     | ZLEXCOUNT key min max                                                                                               |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      ZMSCORE      |    Yes     | ZMSCORE key member [member …]                                                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      ZPOPMAX      |    Yes     | ZPOPMAX key [count]                                                                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      ZPOPMIN      |    Yes     | ZPOPMIN key [count]                                                                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    ZRANDMEMBER    |    Yes     | ZRANDMEMBER key [options]                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      ZRANGE       |    Yes     | ZRANGE key min max [BYSCORE|BYLEX] [REV] [LIMIT] [WITHSCORES]                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    ZRANGEBYLEX    |    Yes     | ZRANGEBYLEX key min max [LIMIT]                                                                                     |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|   ZRANGEBYSCORE   |    Yes     | ZRANGEBYSCORE key min max [WITHSCORES] [LIMIT]                                                                      |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    ZRANGESTORE    |    Yes     | ZRANGESTORE dst src min max [BYSCORE|BYLEX] [REV] [LIMIT]                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       ZRANK       |    Yes     | ZRANK key member                                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       ZREM        |    Yes     | ZREM key member [member …]                                                                                          |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|  ZREMRANGEBYLEX   |    Yes     | ZREMRANGEBYLEX key min max                                                                                          |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|  ZREMRANGEBYRANK  |    Yes     | ZREMRANGEBYRANK key start stop                                                                                      |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
| ZREMRANGEBYSCORE  |    Yes     | ZREMRANGEBYSCORE key min max                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     ZREVRANGE     |    Yes     | ZREVRANGE key start stop [WITHSCORES]                                                                               |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|  ZREVRANGEBYLEX   |    Yes     | ZREVRANGEBYLEX key max min [LIMIT]                                                                                  |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
| ZREVRANGEBYSCORE  |    Yes     | ZREVRANGEBYSCORE key max min [WITHSCORES] [LIMIT]                                                                   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     ZREVRANK      |    Yes     | ZREVRANK key member                                                                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       ZSCAN       |    Yes     | ZSCAN key cursor [MATCH] [COUNT]                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      ZSCORE       |    Yes     | ZSCORE key member                                                                                                   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      ZUNION       |    Yes*    | ZUNION numkeys key [key …] [WEIGHTS] [SUM|MIN|MAX] [WITHSCORES]                                                     |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    ZUNIONSTORE    |    Yes*    | ZUNIONSTORE destination numkeys key [key …] [WEIGHTS] [SUM|MIN|MAX]                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
  • ZINTERSTORE and ZUNIONSTORE support requires that the supplied keys hash to the same server. You can ensure this by using the same hashtag for all keys in the command. Twemproxy does no checking on its end to verify that all the keys hash to the same server, and the given command is forwarded to the server that the first key hashes to.

HyperLogLog

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       PFADD       |    Yes     | PFADD key element [element …]                                                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      PFCOUNT      |    Yes     | PFCOUNT key [key …]                                                                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      PFMERGE      |    Yes*    | PFMERGE destkey sourcekey [sourcekey …]                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
  • PFMERGE support requires that the supplied keys hash to the same server. You can ensure this by using the same hashtag for all keys in the command. Twemproxy does no checking on its end to verify that all the keys hash to the same server, and the given command is forwarded to the server that the first key hashes to.

Geo Command

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      GEOADD       |    Yes     | GEOADD key [NX|XX] [CH] longitude latitude member [longitude latitude member …]                                     |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      GEODIST      |    Yes     | GEODIST key member1 member2 [m|km|ft|mi]                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      GEOHASH      |    Yes     | GEOHASH key member [member …]                                                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      GEOPOS       |    Yes     | GEOPOS key member [member …]                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     GEORADIUS     |    Yes     | GEORADIUS key longitude latitude radius m|km|ft|mi [WITHCOORD] [WITHDIST] [WITHHASH] [count] [ASC|DESC] [STORE] [STOREDIST]|
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
| GEORADIUSBYMEMBER |    Yes     | GEORADIUSBYMEMBER key member radius m|km|ft|mi [WITHCOORD] [WITHDIST] [WITHHASH] [count] [ASC|DESC] [STORE] [STOREDIST]|
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     GEOSEARCH     |    Yes     | GEOSEARCH key [FROMMEMBER] [FROMLONLAT] [circle] [box] [ASC|DESC] [count] [WITHCOORD] [WITHDIST] [WITHHASH]         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|  GEOSEARCHSTORE   |    Yes     | GEOSEARCHSTORE destination source [FROMMEMBER] [FROMLONLAT] [circle] [box] [ASC|DESC] [count] [WITHCOORD] [WITHDIST] [WITHHASH] [STOREDIST]|
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+

Pub/Sub(不支持)

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    PSUBSCRIBE     |    No      | PSUBSCRIBE pattern [pattern …]                                                                                      |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      PUBLISH      |    No      | PUBLISH channel message                                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      PUBSUB       |    No      | PUBSUB subcommand [argument [argument …]]                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|   PUNSUBSCRIBE    |    No      | PUNSUBSCRIBE [pattern [pattern …]]                                                                                  |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     SUBSCRIBE     |    No      | SUBSCRIBE channel [channel …]                                                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    UNSUBSCRIBE    |    No      | UNSUBSCRIBE [channel [channel …]]                                                                                   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+

Transactions(不支持)

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      DISCARD      |    No      | DISCARD                                                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       EXEC        |    No      | EXEC                                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       MULTI       |    No      | MULTI                                                                                                               |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      UNWATCH      |    No      | UNWATCH                                                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       WATCH       |    No      | WATCH key [key …]                                                                                                   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+

Scripting(部分不支持)

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       EVAL        |    Yes*    | EVAL script numkeys key [key …] arg [arg …]                                                                         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      EVALSHA      |    Yes*    | EVALSHA sha1 numkeys key [key …] arg [arg …]                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|   SCRIPT DEBUG    |    No      | SCRIPT DEBUG YES|SYNC|NO                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|   SCRIPT EXISTS   |    No      | SCRIPT EXISTS sha1 [sha1 …]                                                                                         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|   SCRIPT FLUSH    |    No      | SCRIPT FLUSH [ASYNC|SYNC]                                                                                           |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    SCRIPT KILL    |    No      | SCRIPT KILL                                                                                                         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    SCRIPT LOAD    |    No      | SCRIPT LOAD script                                                                                                  |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
  • EVAL and EVALSHA support is limited to scripts that take at least 1 key. If multiple keys are used, all keys must hash to the same server. You can ensure this by using the same hashtag for all keys. If you use more than 1 key, the proxy does no checking to verify that all keys hash to the same server, and the entire command is forwarded to the server that the first key hashes to

Connection(部分不支持)

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       AUTH        |    No      | AUTH password                                                                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       ECHO        |    No      | ECHO message                                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       PING        |    Yes     | PING                                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|       QUIT        |    Yes     | QUIT                                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      SELECT       |    No      | SELECT index                                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+

Server(部分不支持)

+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    BGREWRITEAOF   |    No      | BGREWRITEAOF                                                                                                        |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      BGSAVE       |    No      | BGSAVE                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    CLIENT KILL    |    No      | CLIENT KILL ip:port                                                                                                 |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    CLIENT LIST    |    No      | CLIENT LIST                                                                                                         |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    CONFIG GET     |    No      | CONFIG GET parameter                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    CONFIG SET     |    No      | CONFIG SET parameter value                                                                                          |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|  CONFIG RESETSTAT |    No      | CONFIG RESETSTAT                                                                                                    |
+-------------------+-------------+--------------------------------------------------------------------------------------------------------------------+
|     DBSIZE        |    No      | DBSIZE                                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    DEBUG OBJECT   |    No      | DEBUG OBJECT key                                                                                                    |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|    DEBUG SEGFAULT |    No      | DEBUG SEGFAULT                                                                                                      |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     FLUSHALL      |    No      | FLUSHALL                                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     FLUSHDB       |    No      | FLUSHDB                                                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      INFO         |    No      | INFO                                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     LASTSAVE      |    No      | LASTSAVE                                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     MONITOR       |    No      | MONITOR                                                                                                             |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      SAVE         |    No      | SAVE                                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     SHUTDOWN      |    No      | SHUTDOWN [NOSAVE] [SAVE]                                                                                            |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     SLAVEOF       |    No      | SLAVEOF host port                                                                                                   |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     SLOWLOG       |    No      | SLOWLOG subcommand [argument]                                                                                       |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      SYNC         |    No      | SYNC                                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|      TIME         |    No      | TIME                                                                                                                |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     COMMAND       |    Yes     | COMMAND                                                                                                     |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
|     LOLWUT        |    Yes     | LOLWUT [ argument ...]                                                                                              |
+-------------------+------------+---------------------------------------------------------------------------------------------------------------------+
  • COMMAND is forwarded to an arbitrarily chosen redis backend for the benefit of tools such as redis-cli.
    It assumes that all proxied redis servers support the same backend.
    There is no post-processing; Commands that are not supported by twemproxy are not filtered out.
  • LOLWUT is also forwarded to an arbitrarily chosen redis backend because it does not depend on the state of the database and the presence of the command would not affect production applications.
    It can be used as a reference for adding future commands with no keys and a variable-length argument list.
    Other commands such as TIME continue to be unsupported. They may vary based on state of the database (e.g. out of sync clocks). Using EVAL with a key known to be on the specific backend server can be done instead.

Note

  • redis commands are not case sensitive
  • only vectored commands ‘MGET key [key …]’, ‘MSET key value [key value …]’, ‘DEL key [key …]’, ‘UNLINK key [key …]’, ‘EXISTS key [key …]’ needs to be fragmented

Performance

Setup

  • redis-server running on machine A.
  • nutcracker running on machine A as a local proxy to redis-server.
  • redis-benchmark running on machine B.
  • machine A != machine B.
  • nutcracker built with –enable-debug=no
  • nutcracker running with mbuf-size of 512 (-m 512)
  • redis-server built from redis 2.6 branch

redis-benchmark against redis-server

$ redis-benchmark -h <machine-A> -q -t set,get,incr,lpush,lpop,sadd,spop,lpush,lrange -c 100 -p 6379
SET: 89285.71 requests per second
GET: 92592.59 requests per second
INCR: 89285.71 requests per second
LPUSH: 90090.09 requests per second
LPOP: 90090.09 requests per second
SADD: 90090.09 requests per second
SPOP: 93457.95 requests per second
LPUSH (needed to benchmark LRANGE): 89285.71 requests per second
LRANGE_100 (first 100 elements): 36496.35 requests per second
LRANGE_300 (first 300 elements): 15748.03 requests per second
LRANGE_500 (first 450 elements): 11135.86 requests per second
LRANGE_600 (first 600 elements): 8650.52 requests per second

redis-benchmark against nutcracker proxing redis-server

$ redis-benchmark -h <machine-A> -q -t set,get,incr,lpush,lpop,sadd,spop,lpush,lrange -c 100 -p 22121
SET: 85470.09 requests per second
GET: 86956.52 requests per second
INCR: 85470.09 requests per second
LPUSH: 84745.77 requests per second
LPOP: 86206.90 requests per second
SADD: 84745.77 requests per second
SPOP: 86956.52 requests per second
LPUSH (needed to benchmark LRANGE): 84745.77 requests per second
LRANGE_100 (first 100 elements): 29761.90 requests per second
LRANGE_300 (first 300 elements): 12376.24 requests per second
LRANGE_500 (first 450 elements): 8605.85 requests per second
LRANGE_600 (first 600 elements): 6587.62 requests per second

redis-auth feature

  • you can enable redis-auth for a pool with ‘redis_auth’:

      alpha:
    listen: 127.0.0.1:22121
    hash: fnv1a_64
    distribution: ketama
    redis: true
    redis_auth: testpass

  • notice:

    • MUST set all redis with a same passwd, and all twemproxy with the same passwd
    • Length of password should be less than 256

redis-sentinel feature

  • You can configure sentinel for a pool with ‘sentinels’ to let twemproxy works with sentinel:

      sigma:
    listen: 127.0.0.1:22125
    hash: fnv1a_64
    distribution: ketama
    auto_eject_hosts: false
    redis: true
    server_retry_timeout: 2000
    server_failure_limit: 1
    servers:
      - 127.0.0.1:6379:1 server1
      - 127.0.0.1:6380:1 server2
    sentinels:
      - 127.0.0.1:26379:1
      - 127.0.0.1:26380:1
      - 127.0.0.1:26381:1

  • notice:

    • You should configure all the sentinels you used. Twemproxy will connect to the alive sentinels when some are down
    • Weight of sentinel is not used. Twemproxy keeps it because of the server load code reuse

See sentinel.md for more details.

Memcache Command Support

Request

  • Twemproxy implements only the memached ASCII commands
  • Binary commands are currently unsupported

Ascii Storage Command

+-------------------+------------+--------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                   |
+-------------------+------------+--------------------------------------------------------------------------+
|        set        |    Yes     | set <key> <flags> <expiry> <datalen> [noreply]\r\n<data>\r\n             |
+-------------------+------------+--------------------------------------------------------------------------+
|        add        |    Yes     | add <key> <flags> <expiry> <datalen> [noreply]\r\n<data>\r\n             |
+-------------------+------------+--------------------------------------------------------------------------+
|      replace      |    Yes     | replace <key> <flags> <expiry> <datalen> [noreply]\r\n<data>\r\n         |
+-------------------+------------+--------------------------------------------------------------------------+
|      append       |    Yes     | append <key> <flags> <expiry> <datalen> [noreply]\r\n<data>\r\n          |
+-------------------+------------+--------------------------------------------------------------------------+
|      prepend      |    Yes     | prepend <key> <flags> <expiry> <datalen> [noreply]\r\n<data>\r\n         |
+-------------------+------------+--------------------------------------------------------------------------+
|       cas         |    Yes     | cas <key> <flags> <expiry> <datalen> <cas> [noreply]\r\n<data>\r\n       |
+-------------------+------------+--------------------------------------------------------------------------+
  • Where,
    • - uint32_t : data specific client side flags
    • - uint32_t : expiration time (in seconds)
    • - uint32_t : size of the data (in bytes)
    • - uint8_t[]: data block
    • - uint64_t

Ascii Retrieval Command

+-------------------+------------+--------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                   |
+-------------------+------------+--------------------------------------------------------------------------+
|        get        |    Yes     | get <key> [<key>]+\r\n                                                   |
+-------------------+------------+--------------------------------------------------------------------------+
|        gets       |    Yes     | gets <key> [<key>]+\r\n                                                  |
+-------------------+------------+--------------------------------------------------------------------------+

Ascii Delete

+-------------------+------------+--------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                   |
+-------------------+------------+--------------------------------------------------------------------------+
|        delete     |    Yes     | delete <key> [noreply]\r\n                                               |
+-------------------+------------+--------------------------------------------------------------------------+

Ascii Arithmetic Command

+-------------------+------------+--------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                   |
+-------------------+------------+--------------------------------------------------------------------------+
|        incr       |    Yes     | incr <key> <value> [noreply]\r\n                                         |
+-------------------+------------+--------------------------------------------------------------------------+
|        decr       |    Yes     | decr <key> <value> [noreply]\r\n                                         |
+-------------------+------------+--------------------------------------------------------------------------+
  • Where,
    • - uint64_t

Ascii Misc Command

+-------------------+------------+--------------------------------------------------------------------------+
|      Command      | Supported? | Format                                                                   |
+-------------------+------------+--------------------------------------------------------------------------+
|       touch       |    Yes     | touch <key> <expiry>[noreply]\r\n                                        |
+-------------------+------------+--------------------------------------------------------------------------+
|        gat        |  Planned   | gat <expiry> <key>+\r\n                                                  |
+-------------------+------------+--------------------------------------------------------------------------+
|        gats       |  Planned   | gats <expiry> <key>+\r\n                                                 |
+-------------------+------------+--------------------------------------------------------------------------+
|        quit       |    Yes     | quit\r\n                                                                 |
+-------------------+------------+--------------------------------------------------------------------------+
|      flush_all    |    No      | flush_all [<delay>] [noreply]\r\n                                        |
+-------------------+------------+--------------------------------------------------------------------------+
|      version      |    Yes     | version\r\n                                                              |
+-------------------+------------+--------------------------------------------------------------------------+
|      verbosity    |    No      | verbosity <num> [noreply]\r\n                                            |
+-------------------+------------+--------------------------------------------------------------------------+
|       stats       |    No      | stats\r\n                                                                |
+-------------------+------------+--------------------------------------------------------------------------+
|       stats       |    No      | stats <args>\r\n                                                         |
+-------------------+------------+--------------------------------------------------------------------------+

Response

Error Responses

ERROR\r\n
CLIENT_ERROR [error]\r\n
SERVER_ERROR [error]\r\n

Where,
- ERROR means client sent a non-existent command name
- CLIENT_ERROR means that command sent by the client does not conform to the protocol
- SERVER_ERROR means that there was an error on the server side that made processing of the command impossible

Storage Command Responses

STORED\r\n
NOT_STORED\r\n
EXISTS\r\n
NOT_FOUND\r\n

Where,
- STORED indicates success.
- NOT_STORED indicates the data was not stored because condition for an add or replace wasn't met.
- EXISTS indicates that the item you are trying to store with a cas has been modified since you last fetched it.
- NOT_FOUND indicates that the item you are trying to store with a cas does not exist.

Delete Command Responses

NOT_FOUND\r\n
DELETED\r\n

Retrieval Responses

END\r\n
VALUE <key> <flags> <datalen> [<cas>]\r\n<data>\r\nEND\r\n
VALUE <key> <flags> <datalen> [<cas>]\r\n<data>\r\n[VALUE <key> <flags> <datalen> [<cas>]\r\n<data>]+\r\nEND\r\n

Arithmetic Responses

NOT_FOUND\r\n
<value>\r\n

Where,
- <value> - uint64_t : new key value after incr or decr operation

Touch Command Responses

NOT_FOUND\r\n
TOUCHED\r\n

Statistics Response

[STAT <name> <value>\r\n]+END\r\n

Misc Responses

OK\r\n
VERSION <version>\r\n

Notes

  • set always creates mapping irrespective of whether it is present on not.
  • add, adds only if the mapping is not present
  • replace, only replaces if the mapping is present
  • append and prepend command ignore flags and expiry values
  • noreply instructs the server to not send the reply even if there is an error.
  • decr of 0 is 0, while incr of UINT64_MAX is 0
  • maximum length of the key is 250 characters
  • expiry of 0 means that item never expires, though it could be evicted from the cache
  • non-zero expiry is either unix time (# seconds since 01/01/1970) or,
    offset in seconds from the current time (< 60 x 60 x 24 x 30 seconds = 30 days)
  • expiry time is with respect to the server (not client)
  • can be zero and when it is, theblock is empty.
  • Thoughts: