The Redis Enterprise Software admin console shows performance metrics for clusters, nodes, databases, and shards.

Standard metrics

Metric Components measured Description More information
Connections Cluster, Node, Database Number of connections used to access the database
CPU usage Cluster, Node Percent usage of the CPU
Evicted objects/sec1 Database, Shard Number of objects evicted per second Objects are evicted if:
  1. The database reaches its memory_limit
  2. The eviction policy is not configured to no-eviction
  3. The dataset keys are compliant with the selected eviction policy. For example, with the volatile-lru eviction policy, Redis evicts expired keys.
Expired objects/sec1 Database, Shard Number of expired objects per second
Fork CPU usage Database, Shard CPU usage of Redis child forks
Free disk space Cluster, Node Remaining unused disk space
Free ephemeral disk space Cluster, Node Remaining unused disk space on the ephemeral path
Free RAM Cluster, Node RAM available for system use
Hit ratio Database, Shard Calculated as number of operations on existing keys out of the total number of operations number_of_ops_on_existing_keys / total_ops
Incoming traffic1 Cluster, Node, Database Total incoming traffic (in bytes/sec) to the database
Incoming traffic compressed1 Active-Active Total incoming compressed traffic (in bytes/sec) to the database
Incoming traffic uncompressed1 Active-Active Total incoming uncompressed traffic (in bytes/sec) to the database
Latency Database Latency per operation The graph shows average, min, max, and last latency values
Main thread CPU usage Database, Shard Percent of the CPU used by the main thread
Memory limit Database Memory size limit of the database, enforced on used_memory Used memory does not include:
  1. Fragmentation ratio
  2. Replication buffer - By default, set to 10% of used memory and is between 64MB and 2048 MB.
  3. Lua memory limit - Does not exceed 1MB.
Memory usage1 Database Calculated as used memory out of the memory limit used_memory / memory_limit
Ops/sec Cluster, Node, Database, Shard Number of total operations per second Where operations means:
  1. read operations
  2. write operations
  3. other commands operations
Other cmds/sec Database Number of other commands per second For example: PING, AUTH, INFO
Other commands latency Database Latency per other command The graph shows average, min, max, and last latency values
Outgoing traffic1 Cluster, Node, Database Total outgoing traffic (in bytes/sec) from the database
Pending writes max Active-Active Maximum number of write operations queued
Pending writes min Active-Active Minimum number of write operations queued
RAM fragmentation Database, Shard Ratio between the used (allocated) memory and the physical RAM that is used.
Read misses/sec1 Database, Shard Number of read operations (per sec) on nonexistent keys
Reads latency Database Latency per read operation The graph shows average, min, max and last latency values
Reads/sec Database Number of total read operations per second For example: GET
Total CPU usage Database, Shard Percent usage of the CPU
Total keys1 Database, Shard Total number of keys in the dataset (not including replication, even if replication is enabled) Calculated as the sum of all keys of all master shards.
Used memory1 Database, Shard Total memory used by the database, including RAM, Flash (if enabled), and replication (if enabled) Does not include:
  1. Fragmentation overhead
  2. Replica replication buffers at the primary nodes
  3. Memory used by Lua scripts
  4. Copy On Write (COW) operation that can be triggered by:
    • A full replication process
    • A database snapshot process
    • AOF rewrite process
Write misses/sec1 Database, Shard Number of write operations (per sec) on nonexistent keys
Writes latency Database Latency per write operation
Writes/sec Database Number of total write operations per second For example: SET

Redis on Flash (RoF) metrics

These metrics are available for Redis on Flash (RoF) databases.

Measured metrics

Metric Components measured Description
% Values in RAM Database, Shard Percent of keys whose values are stored in RAM
Flash bytes/sec Cluster, Node, Database, Shard Read+write bytes per second on flash storage device
Flash fragmentation Database, Shard Ratio between the (logical) used flash memory and the actual physical flash that is used
Flash IOPS Cluster, Node Rate of Input/Output operations per second on flash storage device
Flash KV ops Node Rate of operations on flash key values (read + write + del) per second
Flash ops/sec Database, Shard Rate of operations on flash key values (read + write + del) per second
Free flash Cluster, Node Free space on flash storage
RAM dataset overhead Database, Shard Percentage of the RAM limit that is used for anything other than values, such as key names, dictionaries, and other overheads
RAM hit ratio Database, Shard Ratio of requests processed directly from RAM to total number of requests processed
RAM limit Database RAM limit in bytes
RAM usage Database Percentage of the RAM limit usage
RAM:Flash access ratio Database, Shard Ratio between logical Redis key value operations and actual flash key value operations
Used Flash Database, Shard Total RAM used to store values in flash
Used RAM Database, Shard Total size of data stored in RAM, including keys, values, overheads, and replication (if enabled)
Values in Flash Database, Shard Number of keys with values stored in flash, not including replication
Values in RAM Database, Shard Number of keys with values stored in RAM, not including replication

Calculated metrics

You can calculate the following RoF metrics with Measured metrics.

  • RoF average key size with overhead

    avg_key_size = (ram_dataset_overhead * used_ram)
                    / (total_keys * 2)
    
  • RoF average value size in RAM

    avg_ram_value_size = ((1 - ram_dataset_overhead) * used_ram)    
                        / (values_in_ram * 2)
    
  • RoF average value size in flash

    avg_flash_value_size = used_flash / values_in_flash    
    

Footnotes


  1. These metrics are not collected during shard migration. If you view the database or shard metrics while resharding, the graph is blank. ↩︎