# Metrics for Redis

The `AWS/ElastiCache`

namespace includes the following Redis metrics.

With the exception of `ReplicationLag`

, these metrics are derived from the Redis
**info** command. Each metric is calculated at the cache node level.

For complete documentation of the Redis **info** command, go to
http://redis.io/commands/info.

See Also

Metric | Description | Unit |
---|---|---|

`BytesUsedForCache` | The total number of bytes allocated by Redis. | Bytes |

`CacheHits` | The number of successful key lookups. | Count |

`CacheMisses` | The number of unsuccessful key lookups. | Count |

`CurrConnections` | The number of client connections, excluding connections from read replicas. | Count |

`Evictions` | The number of keys that have been evicted due to the
`maxmemory` limit. | Count |

`HyperLogLogBasedCmds` | The total number of `HyperLogLog` based commands.
This is derived from the Redis `commandstats` statistic
by summing all of the pf type of commands
(pfadd, pfcount,
pfmerge). | Count |

`NewConnections` | The total number of connections that have been accepted by the server during this period. | Count |

`Reclaimed` | The total number of key expiration events. | Count |

`ReplicationBytes` | For primaries with attached replicas, `ReplicationBytes`
reports the number of bytes that the primary is sending to all of its replicas.
This metric is representative of the write load on the replication group. For
replicas and standalone primaries, `ReplicationBytes` is always 0.
| Bytes |

`ReplicationLag` | This metric is only applicable for a cache node running as a read replica. It represents how far behind, in seconds, the replica is in applying changes from the primary cache cluster. | Seconds |

`SaveInProgress` | This binary metric returns 1 whenever a background save
(forked or forkless) is in progress, and 0 otherwise. A background
save process is typically used during snapshots and syncs. These
operations can cause degraded performance. Using the ```
SaveInProgress
``` metric, you can diagnose whether or not
degraded performance was caused by a background save process. | Count |

These are aggregations of certain kinds of commands, derived from **info
commandstats**:

Metric | Description | Unit |
---|---|---|

`CurrItems` | The number of items in the cache. This is derived from the Redis
`keyspace` statistic, summing all of the keys in the entire
keyspace. | Count |

`GetTypeCmds` | The total number of get types of commands. This
is derived from the Redis `commandstats` statistic by summing all of the
get types of commands
(get, mget,
hget, etc.) | Count |

`HashBasedCmds` | The total number of commands that are hash-based. This is derived
from the Redis `commandstats` statistic by summing all of the commands
that act upon one or more hashes. | Count |

`KeyBasedCmds` | The total number of commands that are key-based. This is derived from
the Redis `commandstats` statistic by summing all of the commands that act
upon one or more keys. | Count |

`ListBasedCmds` | The total number of commands that are list-based. This is derived
from the Redis `commandstats` statistic by summing all of the commands
that act upon one or more lists. | Count |

`SetBasedCmds` | The total number of commands that are set-based. This is derived from
the Redis `commandstats` statistic by summing all of the commands that act
upon one or more sets. | Count |

`SetTypeCmds` | The total number of set types of commands. This
is derived from the Redis `commandstats` statistic by summing all of the
set types of commands
(set, hset, etc.) | Count |

`SortedSetBasedCmds` | The total number of commands that are sorted set-based. This is
derived from the Redis `commandstats` statistic by summing all of the
commands that act upon one or more sorted sets. | Count |

`StringBasedCmds` | The total number of commands that are string-based. This is derived
from the Redis `commandstats` statistic by summing all of the commands
that act upon one or more strings. | Count |