1. INFO
info指令返回服务器相关信息，包括：
server: General information about the Redis server
clients: Client connections section
memory: Memory consumption related information
persistence: RDB and AOF related information
stats: General statistics
replication: Master/slave replication information
cpu: CPU consumption statistics
commandstats: Redis command statistics
cluster: Redis Cluster section
keyspace: Database related statistics
其本身支持定制返回列表：
[root@~]# redis-cli info
[root@~]# redis-cli info default
[root@~]# redis-cli info all
详情请见： http://www.redis.cn/commands/info.html
2. MONITOR
MONITOR是一个调试命令，返回服务器处理的每一个命令，它能帮助我们了解在数据库上发生了什么操作。共有3种操作方法：
[root@~]# redis-cli monitor
OK
1417532512.619715 [0 127.0.0.1:55043] "REPLCONF" "ACK" "6623624"
[root@~]# telnet 127.0.0.1 6379
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
monitor
+OK
+1417532567.733458 [0 127.0.0.1:55043] "REPLCONF" "ACK" "6623708"
+1417532568.735936 [0 127.0.0.1:55043] "REPLCONF" "ACK" "6623708"
quit
+OK
Connection closed by foreign host.
[root@~]# redis-cli
127.0.0.1:6379> monitor
OK
1417532590.785487 [0 127.0.0.1:55043] "REPLCONF" "ACK" "6623736"
由于MONITOR命令返回服务器处理的所有的命令, 所以在性能上会有一些消耗。使用官方的压测工具测试结果如下
在不运行MONITOR命令的情况下，benchmark的测试结果:
[root@~/software/redis-2.8.17]# src/redis-benchmark -c 10 -n 100000 -q
PING_INLINE: 51020.41 requests per second
PING_BULK: 50607.29 requests per second
SET: 37257.82 requests per second
GET: 49800.80 requests per second
INCR: 38699.69 requests per second
LPUSH: 38910.51 requests per second
LPOP: 39277.30 requests per second
SADD: 54614.96 requests per second
SPOP: 51948.05 requests per second
LPUSH (needed to benchmark LRANGE): 38819.88 requests per second
LRANGE_100 (first 100 elements): 20112.63 requests per second
LRANGE_300 (first 300 elements): 9025.27 requests per second
LRANGE_500 (first 450 elements): 6836.67 requests per second
LRANGE_600 (first 600 elements): 5406.28 requests per second
MSET (10 keys): 19394.88 requests per second
在运行MONITOR命令的情况下，benchmark的测试结果: (redis-cli monitor > /dev/null):
[root@~/software/redis-2.8.17]# src/redis-benchmark -c 10 -n 100000 -q
PING_INLINE: 42211.91 requests per second
PING_BULK: 42936.88 requests per second
SET: 26143.79 requests per second
GET: 33990.48 requests per second
INCR: 26553.37 requests per second
LPUSH: 27337.34 requests per second
LPOP: 27225.70 requests per second
SADD: 30459.95 requests per second
SPOP: 39494.47 requests per second
LPUSH (needed to benchmark LRANGE): 26315.79 requests per second
LRANGE_100 (first 100 elements): 22055.58 requests per second
LRANGE_300 (first 300 elements): 8104.38 requests per second
LRANGE_500 (first 450 elements): 6371.05 requests per second
LRANGE_600 (first 600 elements): 5031.95 requests per second
MSET (10 keys): 14861.05 requests per second
可以看到各项指标基本都有所下降。
详情请见： http://www.redis.cn/commands/monitor.html
3. SLOWLOG
通过SLOWLOG可以读取慢查询日志。
使用SLOWLOG LEN就可以获取当前慢日志长度。
[root@~/software/redis-2.8.17]# redis-cli
127.0.0.1:6379> slowlog len
(integer) 28
使用SLOWLOG GET就可以获取所有慢日志。
127.0.0.1:6379> slowlog get
1) 1) (integer) 27
2) (integer) 1417531320
3) (integer) 24623
4) 1) "info"
其中，各项指标表示：
A unique progressive identifier for every slow log entry.
The unix timestamp at which the logged command was processed.
The amount of time needed for its execution, in microseconds（注意，microseconds翻译成微秒，而不是毫秒）.
The array composing the arguments of the command.
使用SLOWLOG GET N就可以获取最近N条慢日志。
127.0.0.1:6379> slowlog get 2
1) 1) (integer) 27
2) (integer) 1417531320
3) (integer) 24623
4) 1) "info"
2) 1) (integer) 26
2) (integer) 1417528379
3) (integer) 21363
4) 1) "get"
2) "user:score"
使用SLOWLOG RESET命令重置慢日志。一旦执行，将丢失以前的所有慢日志。
127.0.0.1:6379> slowlog reset