Introduction to redis info command

redis info commandReturns various information about the Redis server in a format that is easy to interpret (parse) and easy to read. information and statistical values.

By giving the optional parameter section , the command can return only a certain part of the information:

1. server: general Redis server information, including the following fields:

redis_version : Redis server version

redis_git_sha1 : Git SHA1

redis_git_dirty : Git dirty flag

os : Redis server host Operating system

arch_bits: Architecture (32 or 64 bit)

multiplexing_api: The event handling mechanism used by Redis

gcc_version: The GCC version used when compiling Redis

process_id: PID of the server process

run_id: Random identifier of the Redis server (for Sentinel and cluster)

tcp_port: TCP/IP listening port

uptime_in_seconds: The number of seconds that have elapsed since the Redis server was started

uptime_in_days: The number of days that have elapsed since the Redis server was started

lru_clock: A self-increasing clock in minutes, used for LRU Management

2. clients: Connected client information, including the following fields:

connected_clients: The number of connected clients (excluding clients connected through slave servers )

client_longest_output_list: The longest output list among the currently connected clients

client_longest_input_buf: The largest input cache among the currently connected clients

blocked_clients: Waiting for blocking Number of clients for commands (BLPOP, BRPOP, BRPOPLPUSH)

3. memory: memory information, including the following fields:

used_memory: memory allocated by the Redis allocator Total amount, in bytes

used_memory_human: Returns the total amount of memory allocated by Redis in human-readable format

used_memory_rss: From the perspective of the operating system, returns the amount of memory allocated by Redis The total amount of memory (commonly known as the resident set size). This value is consistent with the output of commands such as top and ps.

used_memory_peak: Peak memory consumption of Redis (in bytes)

used_memory_peak_human: Returns peak memory consumption of Redis in human-readable format

used_memory_lua: Lua engine The memory size used (in bytes)

mem_fragmentation_ratio : The ratio between used_memory_rss and used_memory

mem_allocator : Specified at compile time, the memory allocator used by Redis. Can be libc, jemalloc or tcmalloc.

Ideally, the value of used_memory_rss should be only slightly higher than used_memory.

When rss > used and the difference between the two values ​​is large, it means that there is (internal or external) memory fragmentation.

The ratio of memory fragmentation can be seen through the value of mem_fragmentation_ratio.

When used > rss , it means that part of the memory of Redis has been swapped out to the swap space by the operating system. In this case, the operation may cause significant delays.

Because Redis does not have control over how its allocations are mapped to memory pages, high used_memory_rss is often the result of a spike in memory usage.

When Redis releases memory, the allocator may May or may not return memory to the operating system.

If Redis releases memory but does not return the memory to the operating system, then the value of used_memory may not be consistent with the memory usage of Redis displayed by the operating system.

View the value of used_memory_peak to verify whether this occurs.

4. Persistence: RDB and AOF related information

5. Stats: General statistical information

6. Replication: Master/slave replication information

7. cpu: CPU calculation statistics

8. commandstats: Redis command statistics

9. cluster: Redis cluster information

10. keyspace: database-related statistics Information

In addition to the values ​​given above, the parameters can also be the following two:

11, all: return all information

12, default: return to the default Selected information

When the INFO command is called directly without parameters, use default as the default parameter.

Different versions of Redis may add or delete some of the fields returned.

Therefore, a robust client program should be able to skip unrecognized fields and handle missing fields appropriately when parsing the output of the INFO command.

Available versions:

>= 1.0.0

Time complexity:

O(1)

Return value:

Please refer to the test below for details Code:

redis> INFO
# Server
redis_version:2.5.9
redis_git_sha1:473f3090
redis_git_dirty:0
os:Linux 3.3.7-1-ARCH i686
arch_bits:32
multiplexing_api:epoll
gcc_version:4.7.0
process_id:8104
run_id:bc9e20c6f0aac67d0d396ab950940ae4d1479ad1
tcp_port:6379
uptime_in_seconds:7
uptime_in_days:0
lru_clock:1680564

# Clients
connected_clients:1
client_longest_output_list:0
client_biggest_input_buf:0
blocked_clients:0

# Memory
used_memory:439304
used_memory_human:429.01K
used_memory_rss:13897728
used_memory_peak:401776
used_memory_peak_human:392.36K
used_memory_lua:20480
mem_fragmentation_ratio:31.64
mem_allocator:jemalloc-3.0.0

# Persistence
loading:0
rdb_changes_since_last_save:0
rdb_bgsave_in_progress:0
rdb_last_save_time:1338011402
rdb_last_bgsave_status:ok
rdb_last_bgsave_time_sec:-1
rdb_current_bgsave_time_sec:-1
aof_enabled:0
aof_rewrite_in_progress:0
aof_rewrite_scheduled:0
aof_last_rewrite_time_sec:-1
aof_current_rewrite_time_sec:-1

# Stats
total_connections_received:1
total_commands_processed:0
instantaneous_ops_per_sec:0
rejected_connections:0
expired_keys:0
evicted_keys:0
keyspace_hits:0
keyspace_misses:0
pubsub_channels:0
pubsub_patterns:0
latest_fork_usec:0

# Replication
role:master
connected_slaves:0

# CPU
used_cpu_sys:0.03
used_cpu_user:0.01
used_cpu_sys_children:0.00
used_cpu_user_children:0.00

For more redis knowledge, please pay attention to the redis introductory tutorial column.

The above is the detailed content of Introduction to redis info command. For more information, please follow other related articles on the PHP Chinese website!