INFO

INFO [section]

Available since: 1.0.0
Time complexity: O(1)
ACL categories: @slow, @dangerous

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 Redict server
clients: Client connections section
memory: Memory consumption related information
persistence: RDB and AOF related information
stats: General statistics
replication: Master/replica replication information
cpu: CPU consumption statistics
commandstats: Redict command statistics
latencystats: Redict command latency percentile distribution statistics
sentinel: Redict Sentinel section (only applicable to Sentinel instances)
cluster: Redict Cluster section
modules: Modules section
keyspace: Database related statistics
errorstats: Redict error statistics

It can also take the following values:

all: Return all sections (excluding module generated ones)
default: Return only the default set of sections
everything: Includes all and modules

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

INFO

Notes #

Please note depending on the version of Redict 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 description of fields for Redict >= 2.4.

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

redict_version: Version of the Redict server
redict_git_sha1: Git SHA1
redict_git_dirty: Git dirty flag
redict_build_id: The build id
redict_mode: The server’s mode (“standalone”, “sentinel” or “cluster”)
os: Operating system hosting the Redict server
arch_bits: Architecture (32 or 64 bits)
multiplexing_api: Event loop mechanism used by Redict
atomicvar_api: Atomicvar API used by Redict
gcc_version: Version of the GCC compiler used to compile the Redict server
process_id: PID of the server process
process_supervised: Supervised system (“upstart”, “systemd”, “unknown” or “no”)
run_id: Random value identifying the Redict server (to be used by Sentinel and Cluster)
tcp_port: TCP/IP listen port
server_time_usec: Epoch-based system time with microsecond precision
uptime_in_seconds: Number of seconds since Redict server start
uptime_in_days: Same value expressed in days
hz: The server’s current frequency setting
configured_hz: The server’s configured frequency setting
lru_clock: Clock incrementing every minute, for LRU management
executable: The path to the server’s executable
config_file: The path to the config file
io_threads_active: Flag indicating if I/O threads are active
shutdown_in_milliseconds: The maximum time remaining for replicas to catch up the replication before completing the shutdown sequence. This field is only present during shutdown.

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

connected_clients: Number of client connections (excluding connections from replicas)
cluster_connections: An approximation of the number of sockets used by the cluster’s bus
maxclients: The value of the maxclients configuration directive. This is the upper limit for the sum of connected_clients, connected_slaves and cluster_connections.
client_recent_max_input_buffer: Biggest input buffer among current client connections
client_recent_max_output_buffer: Biggest output buffer among current client connections
blocked_clients: Number of clients pending on a blocking call (BLPOP, BRPOP, BRPOPLPUSH, BLMOVE, BZPOPMIN, BZPOPMAX)
tracking_clients: Number of clients being tracked (CLIENT TRACKING)
pubsub_clients: Number of clients in pubsub mode (SUBSCRIBE, PSUBSCRIBE, SSUBSCRIBE). Added in Redict 8.0
watching_clients: Number of clients in watching mode (WATCH). Added in Redict 8.0
clients_in_timeout_table: Number of clients in the clients timeout table
total_watched_keys: Number of watched keys. Added in Redict 8.0.
total_blocking_keys: Number of blocking keys. Added in Redict 7.2.
total_blocking_keys_on_nokey: Number of blocking keys that one or more clients that would like to be unblocked when the key is deleted. Added in Redict 7.2.

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

used_memory: Total number of bytes allocated by Redict using its allocator (either standard libc, jemalloc, or an alternative allocator such as tcmalloc)
used_memory_human: Human readable representation of previous value
used_memory_rss: Number of bytes that Redict 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
used_memory_peak: Peak memory consumed by Redict (in bytes)
used_memory_peak_human: Human readable representation of previous value
used_memory_peak_perc: The percentage of used_memory_peak out of used_memory
used_memory_overhead: The sum in bytes of all overheads that the server allocated for managing its internal data structures
used_memory_startup: Initial amount of memory consumed by Redict at startup in bytes
used_memory_dataset: The size in bytes of the dataset (used_memory_overhead subtracted from used_memory)
used_memory_dataset_perc: The percentage of used_memory_dataset out of the net memory usage (used_memory minus used_memory_startup)
total_system_memory: The total amount of memory that the Redict host has
total_system_memory_human: Human readable representation of previous value
used_memory_lua: Number of bytes used by the Lua engine for EVAL scripts. Deprecated in Redict 7.0, renamed to used_memory_vm_eval
used_memory_vm_eval: Number of bytes used by the script VM engines for EVAL framework (not part of used_memory). Added in Redict 7.0
used_memory_lua_human: Human readable representation of previous value. Deprecated in Redict 7.0
used_memory_scripts_eval: Number of bytes overhead by the EVAL scripts (part of used_memory). Added in Redict 7.0
number_of_cached_scripts: The number of EVAL scripts cached by the server. Added in Redict 7.0
number_of_functions: The number of functions. Added in Redict 7.0
number_of_libraries: The number of libraries. Added in Redict 7.0
used_memory_vm_functions: Number of bytes used by the script VM engines for Functions framework (not part of used_memory). Added in Redict 7.0
used_memory_vm_total: used_memory_vm_eval + used_memory_vm_functions (not part of used_memory). Added in Redict 7.0
used_memory_vm_total_human: Human readable representation of previous value.
used_memory_functions: Number of bytes overhead by Function scripts (part of used_memory). Added in Redict 7.0
used_memory_scripts: used_memory_scripts_eval + used_memory_functions (part of used_memory). Added in Redict 7.0
used_memory_scripts_human: Human readable representation of previous value
maxmemory: The value of the maxmemory configuration directive
maxmemory_human: Human readable representation of previous value
maxmemory_policy: The value of the maxmemory-policy configuration directive
mem_fragmentation_ratio: Ratio between used_memory_rss and used_memory. Note that this doesn’t only includes fragmentation, but also other process overheads (see the allocator_* metrics), and also overheads like code, shared libraries, stack, etc.
mem_fragmentation_bytes: Delta between used_memory_rss and used_memory. Note that when the total fragmentation bytes is low (few megabytes), a high ratio (e.g. 1.5 and above) is not an indication of an issue.
allocator_frag_ratio:: Ratio between allocator_active and allocator_allocated. This is the true (external) fragmentation metric (not mem_fragmentation_ratio).
allocator_frag_bytes Delta between allocator_active and allocator_allocated. See note about mem_fragmentation_bytes.
allocator_rss_ratio: Ratio between allocator_resident and allocator_active. This usually indicates pages that the allocator can and probably will soon release back to the OS.
allocator_rss_bytes: Delta between allocator_resident and allocator_active
rss_overhead_ratio: Ratio between used_memory_rss (the process RSS) and allocator_resident. This includes RSS overheads that are not allocator or heap related.
rss_overhead_bytes: Delta between used_memory_rss (the process RSS) and allocator_resident
allocator_allocated: Total bytes allocated form the allocator, including internal-fragmentation. Normally the same as used_memory.
allocator_active: Total bytes in the allocator active pages, this includes external-fragmentation.
allocator_resident: Total bytes resident (RSS) in the allocator, this includes pages that can be released to the OS (by MEMORY PURGE, or just waiting).
allocator_muzzy: Total bytes of ‘muzzy’ memory (RSS) in the allocator. Muzzy memory is memory that has been freed, but not yet fully returned to the operating system. It can be reused immediately when needed or reclaimed by the OS when system pressure increases.
mem_not_counted_for_evict: Used memory that’s not counted for key eviction. This is basically transient replica and AOF buffers.
mem_clients_slaves: Memory used by replica clients - Starting Redict 7.0, replica buffers share memory with the replication backlog, so this field can show 0 when replicas don’t trigger an increase of memory usage.
mem_clients_normal: Memory used by normal clients
mem_cluster_links: Memory used by links to peers on the cluster bus when cluster mode is enabled.
mem_aof_buffer: Transient memory used for AOF and AOF rewrite buffers
mem_replication_backlog: Memory used by replication backlog
mem_total_replication_buffers: Total memory consumed for replication buffers - Added in Redict 7.0.
mem_allocator: Memory allocator, chosen at compile time.
mem_overhead_db_hashtable_rehashing: Temporary memory overhead of database dictionaries currently being rehashed - Added in 8.0.
active_defrag_running: When activedefrag is enabled, this indicates whether defragmentation is currently active, and the CPU percentage it intends to utilize.
lazyfree_pending_objects: The number of objects waiting to be freed (as a result of calling UNLINK, or FLUSHDB and FLUSHALL with the ASYNC option)
lazyfreed_objects: The number of objects that have been lazy freed.

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, which can be evaluated by checking allocator_frag_ratio, allocator_frag_bytes. When used » rss, it means part of Redict memory has been swapped off by the operating system: expect some significant latencies.

Because Redict 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 Redict 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 Redict, but not given back to the system. The used_memory_peak value is generally useful to check this point.

Additional introspective information about the server’s memory can be obtained by referring to the MEMORY STATS command and the MEMORY DOCTOR.

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

loading: Flag indicating if the load of a dump file is on-going
async_loading: Currently loading replication data-set asynchronously while serving old data. This means repl-diskless-load is enabled and set to swapdb. Added in Redict 7.0.
current_cow_peak: The peak size in bytes of copy-on-write memory while a child fork is running
current_cow_size: The size in bytes of copy-on-write memory while a child fork is running
current_cow_size_age: The age, in seconds, of the current_cow_size value.
current_fork_perc: The percentage of progress of the current fork process. For AOF and RDB forks it is the percentage of current_save_keys_processed out of current_save_keys_total.
current_save_keys_processed: Number of keys processed by the current save operation
current_save_keys_total: Number of keys at the beginning of the current save operation
rdb_changes_since_last_save: Number of changes since the last dump
rdb_bgsave_in_progress: Flag indicating a RDB save is on-going
rdb_last_save_time: Epoch-based timestamp of last successful RDB save
rdb_last_bgsave_status: Status of the last RDB save operation
rdb_last_bgsave_time_sec: Duration of the last RDB save operation in seconds
rdb_current_bgsave_time_sec: Duration of the on-going RDB save operation if any
rdb_last_cow_size: The size in bytes of copy-on-write memory during the last RDB save operation
rdb_last_load_keys_expired: Number of volatile keys deleted during the last RDB loading. Added in Redict 7.0.
rdb_last_load_keys_loaded: Number of keys loaded during the last RDB loading. Added in Redict 7.0.
aof_enabled: Flag indicating AOF logging is activated
aof_rewrite_in_progress: Flag indicating a AOF rewrite operation is on-going
aof_rewrite_scheduled: Flag indicating an AOF rewrite operation will be scheduled once the on-going RDB save is complete.
aof_last_rewrite_time_sec: Duration of the last AOF rewrite operation in seconds
aof_current_rewrite_time_sec: Duration of the on-going AOF rewrite operation if any
aof_last_bgrewrite_status: Status of the last AOF rewrite operation
aof_last_write_status: Status of the last write operation to the AOF
aof_last_cow_size: The size in bytes of copy-on-write memory during the last AOF rewrite operation
module_fork_in_progress: Flag indicating a module fork is on-going
module_fork_last_cow_size: The size in bytes of copy-on-write memory during the last module fork operation
aof_rewrites: Number of AOF rewrites performed since startup
rdb_saves: Number of RDB snapshots performed since startup

rdb_changes_since_last_save refers to the number of operations that produced some kind of changes in the dataset since the last time either SAVE or BGSAVE was called.

If AOF is activated, these additional fields will be added:

aof_current_size: AOF current file size
aof_base_size: AOF file size on latest startup or rewrite
aof_pending_rewrite: Flag indicating an AOF rewrite operation will be scheduled once the on-going RDB save is complete.
aof_buffer_length: Size of the AOF buffer
aof_rewrite_buffer_length: Size of the AOF rewrite buffer. Note this field was removed in Redict 7.0
aof_pending_bio_fsync: Number of fsync pending jobs in background I/O queue
aof_delayed_fsync: Delayed fsync counter

If a load operation is on-going, these additional fields will be added:

loading_start_time: Epoch-based timestamp of the start of the load operation
loading_total_bytes: Total file size
loading_rdb_used_mem: The memory usage of the server that had generated the RDB file at the time of the file’s creation
loading_loaded_bytes: Number of bytes already loaded
loading_loaded_perc: Same value expressed as a percentage
loading_eta_seconds: ETA in seconds for the load to be complete

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_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
total_net_repl_input_bytes: The total number of bytes read from the network for replication purposes
total_net_repl_output_bytes: The total number of bytes written to the network for replication purposes
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
instantaneous_input_repl_kbps: The network’s read rate per second in KB/sec for replication purposes
instantaneous_output_repl_kbps: The network’s write rate per second in KB/sec for replication purposes
rejected_connections: Number of connections rejected because of maxclients limit
sync_full: The number of full resyncs with replicas
sync_partial_ok: The number of accepted partial resync requests
sync_partial_err: The number of denied partial resync requests
expired_keys: Total number of key expiration events
expired_stale_perc: The percentage of keys probably expired
expired_time_cap_reached_count: The count of times that active expiry cycles have stopped early
expire_cycle_cpu_milliseconds: The cumulative amount of time spent on active expiry cycles
evicted_keys: Number of evicted keys due to maxmemory limit
evicted_clients: Number of evicted clients due to maxmemory-clients limit. Added in Redict 7.0.
evicted_scripts: Number of evicted EVAL scripts due to LRU policy, see EVAL for more details. Added in Redict 8.0.
total_eviction_exceeded_time: Total time used_memory was greater than maxmemory since server startup, in milliseconds
current_eviction_exceeded_time: The time passed since used_memory last rose above maxmemory, in milliseconds
keyspace_hits: Number of successful lookup of keys in the main dictionary
keyspace_misses: Number of failed lookup of keys in the main dictionary
pubsub_channels: Global number of pub/sub channels with client subscriptions
pubsub_patterns: Global number of pub/sub pattern with client subscriptions
pubsubshard_channels: Global number of pub/sub shard channels with client subscriptions. Added in Redict 7.0.3
latest_fork_usec: Duration of the latest fork operation in microseconds
total_forks: Total number of fork operations since the server start
migrate_cached_sockets: The number of sockets open for MIGRATE purposes
slave_expires_tracked_keys: The number of keys tracked for expiry purposes (applicable only to writable replicas)
active_defrag_hits: Number of value reallocations performed by active the defragmentation process
active_defrag_misses: Number of aborted value reallocations started by the active defragmentation process
active_defrag_key_hits: Number of keys that were actively defragmented
active_defrag_key_misses: Number of keys that were skipped by the active defragmentation process
total_active_defrag_time: Total time memory fragmentation was over the limit, in milliseconds
current_active_defrag_time: The time passed since memory fragmentation last was over the limit, in milliseconds
tracking_total_keys: Number of keys being tracked by the server
tracking_total_items: Number of items, that is the sum of clients number for each key, that are being tracked
tracking_total_prefixes: Number of tracked prefixes in server’s prefix table (only applicable for broadcast mode)
unexpected_error_replies: Number of unexpected error replies, that are types of errors from an AOF load or replication
total_error_replies: Total number of issued error replies, that is the sum of rejected commands (errors prior command execution) and failed commands (errors within the command execution)
dump_payload_sanitizations: Total number of dump payload deep integrity validations (see sanitize-dump-payload config).
total_reads_processed: Total number of read events processed
total_writes_processed: Total number of write events processed
io_threaded_reads_processed: Number of read events processed by the main and I/O threads
io_threaded_writes_processed: Number of write events processed by the main and I/O threads
client_query_buffer_limit_disconnections: Total number of disconnections due to client reaching query buffer limit
client_output_buffer_limit_disconnections: Total number of disconnections due to client reaching output buffer limit
reply_buffer_shrinks: Total number of output buffer shrinks
reply_buffer_expands: Total number of output buffer expands
eventloop_cycles: Total number of eventloop cycles
eventloop_duration_sum: Total time spent in the eventloop in microseconds (including I/O and command processing)
eventloop_duration_cmd_sum: Total time spent on executing commands in microseconds
instantaneous_eventloop_cycles_per_sec: Number of eventloop cycles per second
instantaneous_eventloop_duration_usec: Average time spent in a single eventloop cycle in microseconds
acl_access_denied_auth: Number of authentication failures
acl_access_denied_cmd: Number of commands rejected because of access denied to the command
acl_access_denied_key: Number of commands rejected because of access denied to a key
acl_access_denied_channel: Number of commands rejected because of access denied to a channel

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. Note that a replica can be master of another replica (chained replication).
master_failover_state: The state of an ongoing failover, if any.
master_replid: The replication ID of the Redict server.
master_replid2: The secondary replication ID, used for PSYNC after a failover.
master_repl_offset: The server’s current replication offset
second_repl_offset: The offset up to which replication IDs are accepted
repl_backlog_active: Flag indicating replication backlog is active
repl_backlog_size: Total size in bytes of the replication backlog buffer
repl_backlog_first_byte_offset: The master offset of the replication backlog buffer
repl_backlog_histlen: Size in bytes of the data in the replication backlog buffer

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
slave_read_repl_offset: The read replication offset of the replica instance.
slave_repl_offset: The replication offset of the replica instance
slave_priority: The priority of the instance as a candidate for failover
slave_read_only: Flag indicating if the replica is read-only
replica_announced: Flag indicating if the replica is announced by Sentinel.

If a SYNC operation is on-going, these additional fields are provided:

master_sync_total_bytes: Total number of bytes that need to be transferred. this may be 0 when the size is unknown (for example, when the repl-diskless-sync configuration directive is used)
master_sync_read_bytes: Number of bytes already transferred
master_sync_left_bytes: Number of bytes left before syncing is complete (may be negative when master_sync_total_bytes is 0)
master_sync_perc: The percentage master_sync_read_bytes from master_sync_total_bytes, or an approximation that uses loading_rdb_used_mem when master_sync_total_bytes is 0
master_sync_last_io_seconds_ago: Number of seconds since last transfer I/O during a SYNC operation

If the link between master and replica is down, an additional field is provided:

master_link_down_since_seconds: Number of seconds since the link is down

The following field is always provided:

connected_slaves: Number of connected replicas

If the server is configured with the min-slaves-to-write (or starting with Redict 5 with the min-replicas-to-write) directive, an additional field is provided:

min_slaves_good_slaves: Number of replicas currently considered good

For each replica, the following line is added:

slaveXXX: id, IP address, port, state, offset, lag

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

used_cpu_sys: System CPU consumed by the Redict 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 Redict 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 Redict server main thread
used_cpu_user_main_thread: User CPU consumed by the Redict 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: calls=XXX,usec=XXX,usec_per_call=XXX,rejected_calls=XXX,failed_calls=XXX

The latencystats section provides latency percentile distribution statistics based on the command type.

By default, the exported latency percentiles are the p50, p99, and p999. If you need to change the exported percentiles, use CONFIG SET latency-tracking-info-percentiles "50.0 99.0 99.9".

This section requires the extended latency monitoring feature to be enabled (by default it’s enabled). If you need to enable it, use CONFIG SET latency-tracking yes.

For each command type, the following line is added:

latency_percentiles_usec_XXX: p<percentile 1>=<percentile 1 value>,p<percentile 2>=<percentile 2 value>,...

The errorstats section enables keeping track of the different errors that occurred within Redict, based upon the reply error prefix ( The first word after the “-”, up to the first space. Example: ERR ).

For each error type, the following line is added:

errorstat_XXX: count=XXX

The sentinel section is only available in Redict Sentinel instances. It consists of the following fields:

sentinel_masters: Number of Redict masters monitored by this Sentinel instance
sentinel_tilt: A value of 1 means this sentinel is in TILT mode
sentinel_tilt_since_seconds: Duration in seconds of current TILT, or -1 if not TILTed. Added in Redict 7.0.0
sentinel_running_scripts: The number of scripts this Sentinel is currently executing
sentinel_scripts_queue_length: The length of the queue of user scripts that are pending execution
sentinel_simulate_failure_flags: Flags for the SENTINEL SIMULATE-FAILURE command

The cluster section currently only contains a unique field:

cluster_enabled: Indicate Redict cluster is enabled

The modules section contains additional information about loaded modules if the modules provide it. The field part of properties lines in this section is always prefixed with the module’s name.

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

The debug section contains experimental metrics, which might change or get removed in future versions. It won’t be included when INFO or INFO ALL are called, and it is returned only when INFO DEBUG is used.

eventloop_duration_aof_sum: Total time spent on flushing AOF in eventloop in microseconds
eventloop_duration_cron_sum: Total time consumption of cron in microseconds (including serverCron and beforeSleep, but excluding IO and AOF flushing)
eventloop_duration_max: The maximal time spent in a single eventloop cycle in microseconds
eventloop_cmd_per_cycle_max: The maximal number of commands processed in a single eventloop cycle

A note about the word slave used in this man page: Starting with Redict 5, if not for backward compatibility, the Redict project no longer uses the word slave. Unfortunately in this command the word slave is part of the protocol, so we’ll be able to remove such occurrences only when this API will be naturally deprecated.

Modules generated sections: Starting with Redict 6, modules can inject their info into the INFO command, these are excluded by default even when the all argument is provided (it will include a list of loaded modules but not their generated info fields). To get these you must use either the modules argument or everything.,

History #

7.0.0: Added support for taking multiple section arguments.