INFO

Syntax

  1. INFO [section [section ...]]

Time complexity: O(1)

The INFO command returns information and statistics about the server in a format that is simple to parse by computers and easy to read by humans.

The optional parameter can be used to select a specific section of information:

  • server: General information about the Dragonfly server
  • clients: Client connections section
  • memory: Memory consumption related information
  • persistence: Persistence related information
  • stats: General statistics
  • replication: Master/replica replication information
  • cpu: CPU consumption statistics
  • commandstats: Command statistics
  • keyspace: Database related statistics
  • errorstats: Error statistics

It can also take the following values:

  • all: Return all sections (excluding module generated ones)

When no parameter is provided, the default option is assumed.

Return

Bulk string reply: as a collection of text lines.

Lines can contain a section name (starting with a # character) or a property. All the properties are in the form of field:value terminated by \r\n.

  1. dragonfly> INFO
  2. # Server
  3. dragonfly_version:df-dev
  4. redis_mode:standalone
  5. arch_bits:64
  6. multiplexing_api:iouring
  7. tcp_port:6379
  8. uptime_in_seconds:9
  9. uptime_in_days:0
  11. # Clients
  12. connected_clients:1
  13. client_read_buffer_bytes:256
  14. blocked_clients:0
  16. # Memory
  17. used_memory:67219536
  18. used_memory_human:64.11MiB
  19. used_memory_peak:67219536
  20. comitted_memory:134963200
  21. used_memory_rss:128823296
  22. used_memory_rss_human:122.86MiB
  23. object_used_memory:27
  24. table_used_memory:66189280
  25. num_buckets:1720320
  26. num_entries:1005001
  27. inline_keys:1005001
  28. strval_bytes:0
  29. updateval_amount:0
  30. listpack_blobs:0
  31. listpack_bytes:0
  32. small_string_bytes:0
  33. pipeline_cache_bytes:0
  34. maxmemory:3169176780
  35. maxmemory_human:2.95GiB
  36. cache_mode:store
  38. # Stats
  39. total_connections_received:1
  40. total_commands_processed:2
  41. instantaneous_ops_per_sec:0
  42. total_pipelined_commands:0
  43. total_net_input_bytes:14
  44. total_net_output_bytes:11249
  45. instantaneous_input_kbps:-1
  46. instantaneous_output_kbps:-1
  47. rejected_connections:-1
  48. expired_keys:0
  49. evicted_keys:0
  50. hard_evictions:0
  51. garbage_checked:0
  52. garbage_collected:0
  53. bump_ups:0
  54. stash_unloaded:0
  55. traverse_ttl_sec:0
  56. delete_ttl_sec:0
  57. keyspace_hits:0
  58. keyspace_misses:0
  59. total_reads_processed:1
  60. total_writes_processed:1850
  61. async_writes_count:0
  62. parser_err_count:0
  63. defrag_attempt_total:0
  64. defrag_realloc_total:0
  65. defrag_task_invocation_total:0
  67. # Replication
  68. role:master
  69. connected_slaves:0
  70. master_replid:5114684b4a5bc1ab7fa9133c5ac972028c62f576
  72. # Keyspace
  73. db0:keys=1005001,expires=0,avg_ttl=-1
  75. # CPU
  76. used_cpu_sys:0.76107
  77. used_cpu_user:9.353156
  78. used_cpu_sys_children:0.0
  79. used_cpu_user_children:0.0
  80. used_cpu_sys_main_thread:0.32040
  81. used_cpu_user_main_thread:4.681903

Notes

Please note depending on the version of Dragonfly some of the fields have been added or removed. A robust client application should therefore parse the result of this command by skipping unknown properties, and gracefully handle missing fields.

Here is the meaning of all fields in the server section:

  • dragonfly_version: Version of the Dragonfly server
  • redis_mode: The server’s mode (“standalone”, “sentinel” or “cluster”)
  • arch_bits: Architecture (32 or 64 bits)
  • multiplexing_api: Event loop mechanism used by Dragonfly
  • tcp_port: TCP/IP listen port
  • uptime_in_seconds: Number of seconds since Dragonfly server start
  • uptime_in_days: Same value expressed in days

Here is the meaning of all fields in the clients section:

  • connected_clients: Number of client connections (excluding connections from replicas)
  • client_read_buffer_bytes: Client read buffer size in bytes
  • blocked_clients: Number of clients pending on a blocking call (BLPOP, BRPOP, BRPOPLPUSH, BLMOVE, BZPOPMIN, BZPOPMAX)

Here is the meaning of all fields in the memory section:

  • used_memory: Total number of bytes allocated by Dragonfly using its allocator
  • used_memory_human: Human readable representation of previous value
  • used_memory_peak: Peak memory consumed by Dragonfly (in bytes)
  • used_memory_rss: Number of bytes that Dragonfly allocated as seen by the operating system (a.k.a resident set size). This is the number reported by tools such as top(1) and ps(1)
  • used_memory_rss_human: Human readable representation of previous value
  • maxmemory: The value of the maxmemory configuration directive
  • maxmemory_human: Human readable representation of previous value

Ideally, the used_memory_rss value should be only slightly higher than used_memory. When rss >> used, a large difference may mean there is (external) memory fragmentation.

When Dragonfly frees memory, the memory is given back to the allocator, and the allocator may or may not give the memory back to the system. There may be a discrepancy between the used_memory value and memory consumption as reported by the operating system. It may be due to the fact memory has been used and released by Dragonfly, but not given back to the system. The used_memory_peak value is generally useful to check this point.

Here is the meaning of all fields in the persistence section:

  • last_save: Epoch based timestamp of last successful save
  • last_save_duration_sec: Duration of the last save operation in seconds
  • last_save_file: File path of last save file

Here is the meaning of all fields in the stats section:

  • total_connections_received: Total number of connections accepted by the server
  • total_commands_processed: Total number of commands processed by the server
  • instantaneous_ops_per_sec: Number of commands processed per second
  • total_pipelined_commands: Total number of commands pipelined to the server
  • total_net_input_bytes: The total number of bytes read from the network
  • total_net_output_bytes: The total number of bytes written to the network
  • instantaneous_input_kbps: The network’s read rate per second in KB/sec
  • instantaneous_output_kbps: The network’s write rate per second in KB/sec
  • rejected_connections: Number of connections rejected because of maxclients limit
  • expired_keys: Total number of key expiration events
  • evicted_keys: Number of evicted keys due to maxmemory limit
  • keyspace_hits: Number of successful lookup of keys in the main dictionary
  • keyspace_misses: Number of failed lookup of keys in the main dictionary
  • total_reads_processed: Total number of read events processed
  • total_writes_processed: Total number of write events processed

Here is the meaning of all fields in the replication section:

  • role: Value is “master” if the instance is replica of no one, or “slave” if the instance is a replica of some master instance
  • master_replid: The replication ID of the Dragonfly server
  • connected_slaves: Number of connected replicas

If the instance is a replica, these additional fields are provided:

  • master_host: Host or IP address of the master
  • master_port: Master listening TCP port
  • master_link_status: Status of the link (up/down)
  • master_last_io_seconds_ago: Number of seconds since the last interaction with master
  • master_sync_in_progress: Indicate the master is syncing to the replica

For each replica, the following line is added:

  • slaveXXX: id, IP address, port

Here is the meaning of all fields in the cpu section:

  • used_cpu_sys: System CPU consumed by the Dragonfly server, which is the sum of system CPU consumed by all threads of the server process (main thread and background threads)
  • used_cpu_user: User CPU consumed by the Dragonfly server, which is the sum of user CPU consumed by all threads of the server process (main thread and background threads)
  • used_cpu_sys_children: System CPU consumed by the background processes
  • used_cpu_user_children: User CPU consumed by the background processes
  • used_cpu_sys_main_thread: System CPU consumed by the Dragonfly server main thread
  • used_cpu_user_main_thread: User CPU consumed by the Dragonfly server main thread

The commandstats section provides statistics based on the command type, including the number of calls that reached command execution (not rejected), the total CPU time consumed by these commands, the average CPU consumed per command execution, the number of rejected calls (errors prior command execution), and the number of failed calls (errors within the command execution).

For each command type, the following line is added:

  • cmdstat_XXX: XXX - number of calls

The keyspace section provides statistics on the main dictionary of each database. The statistics are the number of keys, and the number of keys with an expiration.

For each database, the following line is added:

  • dbXXX: keys=XXX,expires=XXX, avg_ttl=XXX