redis命令的使用

1. 批量删除特定前缀的keys

   redis-cli KEYS "prefix:*" | xargs redis-cli DEL

2. 返回list的长度

   127.0.0.1:> LPUSH test "hello"
   (integer)
   127.0.0.1:> LPUSH test "world"
   (integer)
   127.0.0.1:> LLEN test
   (integer) 

3. LRANGE的使用

   127.0.0.1:> RPUSH test1 "one"
   (integer)
   127.0.0.1:> RPUSH test1 "two"
   (integer)
   127.0.0.1:> RPUSH test1 "three"
   (integer)
   127.0.0.1:> LRANGE test1
   ) "one"
   127.0.0.1:> LRANGE test1 -
   ) "one"
   ) "two"
   ) "three"
   127.0.0.1:> LRANGE test1 -
   ) "one"
   ) "two"
   ) "three"
   127.0.0.1:> LRANGE test1
   (empty list or set)的使用
   

4. MONITOR的使用
   monitor用来监控正在运行的命令

   redis 127.0.0.1:> MONITOR
   OK
   1371241093.375324 "monitor"
   1371241109.735725 "keys" "*"
   1371241152.344504 "set" "testkey" ""
   1371241165.169184 "get" "testkey"

5. 查询慢查询

   slowlog get  #打印前25个慢的查询
   slowlog len #显示slowlog的长度
   slowlog reset #重置slowlog
   
   例子：
   你可以通过一下命令，查询当前运行比较慢的命令
   slowlog reset
   slowlog get 25

6. 搜索keys

   keys pattern
   keys pattern*
   keys *pattern*
   keys *pattern

7. 通常的操作

   del <key>
   exists <key>
   expire <key> <seconds>
   
   get <key>
   set <key> <value>
   setnx <key> <valule> #仅仅当key不存在的时候，才设置值
   
   mget <key> <key> ...
   mset <key> <value> <key> <value>
   
   incr <key> #增加key中的值的数
   decr <key>

8. 列表

   lrange <key> <start> <stop>
   lrange mylist  - #Get all of a list
   lindex mylist  #Get by index
   llen mylist #Get length
   

   lpush mylist "value"
   lpush mylist 5
   rpush mylist "value"
   
   lpushx mylist 6 #only push in mylist exists
   lpushx mylist 0 #only push in mylist exists
   
   lpop mylist
   rpop mylist
   
   lrem mylist 1 "value" #删除一次为value值的key
   lset mylist 2 6 #mylist[2]=6
   ltrim <key> <start> <stop> #仅仅包含特定范围的值
   
   例子
   127.0.0.1:6379> LPUSH dufeng_test "value"
   (integer) 1
   127.0.0.1:6379> LPUSH dufeng_test 5
   (integer) 2
   127.0.0.1:6379> RPUSH dufeng_test "value"
   (integer) 3
   127.0.0.1:6379> LRANGE dufeng_test 0 4
   1) "5"
   2) "value"
   3) "value"
   
   

9. Hashes命令

   hexists myhash field1 #检查hash key是否存在
   hget myhash field1
   hdel myhash field2
   hset myhash field1 "value"
   hsetnx myhash field1 "value"
   
   hgetall myhash
   hkeys myhash
   hlen myhash
   
   #批量命令
   hmget <key> <key>
   hmset <key> <value> <key> <value>
   
   #计数命令
   hincrby myhash field1 1 
   hincrby myhash field1 5 
   hincrby myhash field1 -1 
   hincrbrfloat myhash field2 1.123445
   
   例子：
   redis> HSET myhash field 5
   (integer) 1
   redis> HINCRBY myhash field 1
   (integer) 6
   redis> HINCRBY myhash field -1
   (integer) 5
   redis> HINCRBY myhash field -10
   (integer) -5

10. 查看客户端的连接数

    [root@hadoop252 ~]# redis-cli info | grep connected
    connected_clients:
    connected_slaves:

11. 服务器统计

    $ redis-cli INFO
    redis_version:2.2.
    redis_git_sha1:
    redis_git_dirty:
    arch_bits:
    multiplexing_api:epoll
    process_id:
    uptime_in_seconds:
    uptime_in_days:
    lru_clock:
    used_cpu_sys:199.20
    used_cpu_user:309.26
    used_cpu_sys_children:12.04
    used_cpu_user_children:1.47
    connected_clients:            # <---- connection count
    connected_slaves:
    client_longest_output_list:
    client_biggest_input_buf:
    blocked_clients:
    used_memory:
    used_memory_human:6.29M            # <---- memory usage
    used_memory_rss:
    mem_fragmentation_ratio:2.66
    use_tcmalloc:
    loading:
    aof_enabled:
    changes_since_last_save:
    bgsave_in_progress:
    last_save_time:
    bgrewriteaof_in_progress:
    total_connections_received:
    total_commands_processed:
    expired_keys:
    evicted_keys:
    keyspace_hits:
    keyspace_misses:
    hash_max_zipmap_entries:
    hash_max_zipmap_value:
    pubsub_channels:
    pubsub_patterns:
    vm_enabled:
    role:master                # <---- master/slave in replication setup
    db0:keys=,expires=

12. 列出连接

    #从2.4版本开始，你可以使用下面的命令列出连接
    CLIENT LIST
    使用下面的命令杀死一个连接
    CLIENT KILL <IP>:<port>

13. 数据库备份

    BGSAVE 

14. debug延迟

    #查看在redis服务器上的系统延迟时间
    redis-cli --intrinsic-latency
    #从客户端查看延迟时间
    redis-cli --latency -h <host> -p <port>
    #如果你看到有比较高的延迟，检测是否透明的大页面是否禁止，使用一下命令禁止它
    echo never > /sys/kernel/mm/transparent_hugepage/enabled

15. 在redis占用内存比较大的keys

    redis-cli --bigkeys