Redis Info Command
The Redis Info command returns various information and statistics about the Redis server in a format that is easy to understand and read.
By giving the optional parameter section, the command can return only a certain part of the information:
server: General Redis server information, containing the following fields:
- redis_version: Redis server version
- redis_git_sha1 : Git SHA1
- redis_git_dirty : Git dirty flag
- os: The host operating system of the Redis server
- arch_bits: Architecture (32 or 64 bits)
- multiplexing_api: The event processing mechanism used by Redis
- gcc_version: The GCC version used to compile Redis
- process_id: PID of the server process
- run_id: Random identifier of the Redis server (used for Sentinel and Cluster)
- tcp_port: TCP/IP listening port
- uptime_in_seconds: Number of seconds elapsed since the Redis server started
- uptime_in_days: Number of days elapsed since the Redis server started
- lru_clock: Clock that increments per minute, used for LRU management
clients: Connected client information, containing the following fields:
- connected_clients: Number of connected clients (excluding clients connected via replica servers)
- client_longest_output_list: Longest output list among currently connected clients
- client_longest_input_buf: Largest input buffer among currently connected clients
- blocked_clients: Number of clients waiting for blocking commands (BLPOP, BRPOP, BRPOPLPUSH)
memory: Memory information, containing the following fields:
- used_memory: Total amount of memory allocated by the Redis allocator, in bytes
- used_memory_human: Returns the total memory allocated by Redis in a human-readable format
- used_memory_rss: Returns the total memory allocated by Redis from the operating system's perspective (commonly known as 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 the peak memory consumption of Redis in a human-readable format
- used_memory_lua: Memory size used by the Lua engine (in bytes)
- mem_fragmentation_ratio: 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.
In an ideal case, 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 indicates the presence of (internal or external) memory fragmentation.
The ratio of memory fragmentation can be seen from the value of mem_fragmentation_ratio.
When used > rss, it means that part of Redis's memory has been swapped out to swap space by the operating system. In this case, operations may produce noticeable delays.
When Redis releases memory, the allocator may or may not return the memory to the operating system.
If Redis releases memory but does not return it to the operating system, the value of used_memory may not be consistent with the Redis memory usage reported by the operating system.
Checking the value of used_memory_peak can verify whether this situation has occurred.
persistence: Information related to RDB and AOF
stats: General statistics
replication: Master/slave replication information
cpu: CPU computation statistics
commandstats: Redis command statistics
cluster: Redis Cluster information
keyspace: Database-related statistics
Syntax
The basic syntax of the Redis Info command is as follows:
redis 127.0.0.1:6379> INFO [section]
Available versions
>= 1.0.0
Return value
String, a collection of text lines.
Examples
redis 127.0.0.1:6379> 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 # Keyspace
Other extensions