Redis memory stats 命令

MEMORY STATS

The MEMORY STATS command returns an Array reply about the memory usage of the
server.

The information about memory usage is provided as metrics and their respective
values. The following metrics are reported:

  • peak.allocated: Peak memory consumed by Redis in bytes (see INFO‘s
    used_memory_peak)
  • total.allocated: Total number of bytes allocated by Redis using its
    allocator (see INFO‘s used_memory)
  • startup.allocated: Initial amount of memory consumed by Redis at startup
    in bytes (see INFO‘s used_memory_startup)
  • replication.backlog: Size in bytes of the replication backlog (see INFO‘s repl_backlog_active)
  • clients.slaves: The total size in bytes of all replicas overheads (output
    and query buffers, connection contexts)
  • clients.normal: The total size in bytes of all clients overheads (output
    and query buffers, connection contexts)
  • aof.buffer: The summed size in bytes of the current and rewrite AOF
    buffers (see INFO‘s aof_buffer_length and aof_rewrite_buffer_length,
    respectively)
  • lua.caches: the summed size in bytes of the overheads of the Lua scripts’
    caches
  • dbXXX: For each of the server’s databases, the overheads of the main and
    expiry dictionaries (overhead.hashtable.main and
    overhead.hashtable.expires, respectively) are reported in bytes
  • overhead.total: The sum of all overheads, i.e. startup.allocated,
    replication.backlog, clients.slaves, clients.normal, aof.buffer and
    those of the internal data structures that are used in managing the
    Redis keyspace (see INFO‘s used_memory_overhead)
  • keys.count: The total number of keys stored across all databases in the
    server
  • keys.bytes-per-key: The ratio between net memory usage (total.allocated
    minus startup.allocated) and keys.count
  • dataset.bytes: The size in bytes of the dataset, i.e. overhead.total
    subtracted from total.allocated (see INFO‘s used_memory_dataset)
  • dataset.percentage: The percentage of dataset.bytes out of the net
    memory usage
  • peak.percentage: The percentage of peak.allocated out of
    total.allocated
  • fragmentation: See INFO‘s mem_fragmentation_ratio

*返回值

Array reply: nested list of memory usage metrics and their values

A note about the word slave used in this man page: Starting with Redis 5, if not for backward compatibility, the Redis 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.