Shulou(Shulou.com)06/01 Report--

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

Given the optional parameter section, you can have the command return only a portion of the information:

1. Server: general Redis server information, including the following domains:

Redis_version: Redis server version

Redis_git_sha1: Git SHA1

Redis_git_dirty: Git dirty flag

Os: host operating system of the Redis server

Arch_bits: architecture (32 or 64 bit)

Multiplexing_api: event handling mechanism used by Redis

Gcc_version: the version of GCC used when compiling Redis

Process_id: PID of the server process

Run_id: random identifier of the Redis server (for Sentinel and clustering)

Tcp_port: TCP/IP listening port

Uptime_in_seconds: the number of seconds that have passed since the Redis server was started

Uptime_in_days: the number of days that have passed since the Redis server was started

Lru_clock: a clock that increments itself in minutes for LRU management

2. Clients: connected client information, including the following domains:

Connected_clients: number of connected clients (excluding clients connected through secondary servers)

Client_longest_output_list: the longest output list among currently connected clients

Client_longest_input_buf: the maximum input cache among the currently connected clients

Blocked_clients: the number of clients waiting for blocking commands (BLPOP, BRPOP, BRPOPLPUSH)

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

Used_memory: the total amount of memory allocated by the Redis allocator in byte

Used_memory_human: returns the total amount of memory allocated by Redis in a human readable format

Used_memory_rss: returns the total amount of memory allocated by Redis (commonly known as resident set size) from an operating system perspective. This value is consistent with the output of top, ps, and so on.

Used_memory_peak: peak memory consumption of Redis (in bytes)

Used_memory_peak_human: returns the peak memory consumption of Redis in a human-readable format

Used_memory_lua: the amount of memory used by the Lua engine in bytes

Mem_fragmentation_ratio: the ratio between used_memory_rss and used_memory

Mem_allocator: the memory allocator used by Redis specified at compile time. It can be libc, jemalloc, or tcmalloc.

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

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

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

When used > rss, part of the memory of the Redis is swapped out to swap space by the operating system, in which case the operation may cause significant latency.

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 frees memory, the allocator may or may not return memory to the operating system.

If Redis frees memory but does not return it to the operating system, the value of used_memory may not match the Redis footprint displayed by the operating system.

Check the value of used_memory_peak to verify that this is happening.

4. Persistence: information about RDB and AOF

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 statistical information

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

11. All: return all information

12. Default: returns the information of default selection

When the INFO command is called directly without arguments, default is used as the default parameter.

Different versions of Redis may have added or deleted some of the returned fields.

Therefore, a robust client program should be able to skip unrecognized domains and properly handle missing ones when analyzing the output of INFO commands.

Available versions:

> = 1.0.0

Time complexity:

O (1)

Return value:

See the following test code for details:

Redis > INFO# Serverredis_version:2.5.9redis_git_sha1:473f3090redis_git_dirty:0os:Linux 3.3.7-1-ARCH i686arch_bits:32multiplexing_api:epollgcc_version:4.7.0process_id:8104run_id:bc9e20c6f0aac67d0d396ab950940ae4d1479ad1tcp_port:6379uptime_in_seconds:7uptime_in_days:0lru_clock:1680564# Clientsconnected_clients:1client_longest_output_list:0client_biggest_input_buf:0blocked_clients:0# Memoryused_memory:439304used_memory_human:429.01Kused _ memory_rss:13897728used_memory_peak:401776used_memory_peak_human:392.36Kused_memory_lua:20480mem_fragmentation_ratio:31.64mem_allocator:jemalloc-3.0.0# Persistenceloading:0rdb_changes_since_last_save:0rdb_bgsave_in_progress:0rdb_last_save_time:1338011402rdb_last_bgsave_status:okrdb_last_bgsave_time_sec:-1rdb_current_bgsave_time_sec:-1aof_enabled:0aof_rewrite_in_progress:0aof_rewrite _ scheduled:0aof_last_rewrite_time_sec:-1aof_current_rewrite_time_sec:-1# Statstotal_connections_received:1total_commands_processed:0instantaneous_ops_per_sec:0rejected_connections:0expired_keys:0evicted_keys:0keyspace_hits:0keyspace_misses:0pubsub_channels:0pubsub_patterns:0latest_fork_usec:0# Replicationrole:masterconnected_slaves:0# CPUused_cpu_sys:0.03used_cpu_user:0.01used_cpu_sys_children:0.00used_cpu_user_children:0.00

These are the details of the redis info command, please pay attention to other related articles!

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