Metrics for Redis
The AWS/ElastiCache namespace includes the following Redis metrics.
With the exception of ReplicationLag and EngineCPUUtilization, 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, see
http://redis.io/commands/info
See Also
| Metric | Description | Unit |
|---|---|---|
ActiveDefragHits |
The number of value reallocations per minute performed
by the active defragmentation process. This is derived from active_defrag_hits statistic at Redis INFO |
Number |
BytesUsedForCache |
The total number of bytes allocated by Redis for all purposes, including the dataset,
buffers, etc. This is derived from used_memory statistic at Redis INFO |
Bytes |
CacheHits |
The number of successful read-only key lookups in the main dictionary. This is derived
from keyspace_hits statistic at Redis INFO |
Count |
CacheMisses |
The number of unsuccessful read-only key lookups in the main dictionary. This is derived
from keyspace_misses at Redis INFO |
Count |
CurrConnections |
The number of client connections, excluding connections from read
replicas. ElastiCache uses two to four of the connections to monitor the
cluster in each case. This is derived from the connected_clients statistic at Redis INFO |
Count |
EngineCPUUtilization |
Provides CPU utilization of the Redis engine thread. Since Redis is single-threaded,
you can use this metric to analyze the load of the Redis process itself.
The |
Percent |
Evictions |
The number of keys that have been evicted due to the
maxmemory limit. This is derived from the evicted_keys statistic at Redis INFO |
Count |
MasterLinkHealthStatus |
This status has two values: 0 or 1. The value 0 indicates that data in the Elasticache primary node is not in sync with Redis on EC2. The value of 1 indicates that the data is in sync. To complete the migration, use the CompleteMigration API. | Boolean |
NewConnections |
The total number of connections that have been accepted by the server
during this period. This is derived from the total_connections_received statistic at Redis INFO |
Count |
Reclaimed |
The total number of key expiration events. This is derived from the expired_keys statistic at Redis INFO |
Count |
ReplicationBytes |
For nodes in a replicated configuration, 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. This is derived from the master_repl_offset statistic
at Redis INFO |
Bytes |
ReplicationLag |
This metric is only applicable for a node running as a read replica. It represents how far behind, in seconds, the replica is in applying changes from the primary node. | For Redis engine version 5.0.6, milliseconds. For all other supported engine versions, 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. This is derived
from the rdb_bgsave_in_progress statistic at Redis INFO |
Count |
EngineCPUUtilization availability
Nodes in a region created or replaced after the date and time specified in the following
table
will include the EngineCPUUtilization metric.
| Region | Region name | EngineCPUUtilization availability | |
|---|---|---|---|
us-east-2 |
US East (Ohio) | February 16, 2017 | 17:21 (UTC) |
us-east-1 |
US East (N. Virginia) | February 8, 2017 | 21:20 (UTC) |
us-west-1 |
US West (N. California) | February 14, 2017 | 22:23 (UTC) |
us-west-2 |
US West (Oregon) | Febrary 20, 2017 | 19:20 (UTC) |
ap-northeast-1 |
Asia Pacific (Tokyo) | February 14, 2017 | 19:58 (UTC) |
ap-northeast-2 |
Asia Pacific (Seoul) | Available on all nodes. | |
ap-northeast-3 |
Asia Pacific (Osaka-Local) | Available on all nodes. | |
ap-south-1 |
Asia Pacific (Mumbai) | February 7, 2017 | 02:51 (UTC) |
ap-southeast-1 |
Asia Pacific (Singapore) | February 13, 2017 | 23:40 (UTC) |
ap-southeast-2 |
Asia Pacific (Sydney) | February 14, 2017 | 03:33 (UTC) |
ca-central-1 |
Canada (Central) | Available on all nodes. | |
cn-north-1 |
China (Beijing) | February 16, 2017 | 22:39 (UTC) |
cn-northwest-2 |
China (Ningxia) | Available on all nodes. | |
eu-central-1 |
Europe (Frankfurt) | February 15, 2017 | 00:46 (UTC) |
eu-west-1 |
Europe (Ireland) | February 7, 2017 | 21:30 (UTC) |
eu-west-2 |
Europe (London) | February 16, 2017 | 18:58 (UTC) |
eu-west-3 |
EU (Paris) | Available on all nodes. | |
sa-east-1 |
South America (São Paulo) | February 7, 2017 | 04:35 (UTC) |
us-gov-west-1 |
AWS GovCloud (US-West) | February 16, 2017 | 20:11 (UTC) |
These are aggregations of certain kinds of commands, derived from info
commandstats. For a full list of available commands, see redis commands
| 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 read-only type commands. This
is derived from the Redis commandstats statistic by summing all of the
read-only type commands (get, hget,
scard, lrange, 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 (hget, hkeys, hvals, hdel, etc).
|
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, etc.).
|
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 across multiple data structures (del, expire, rename, etc.).
|
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 (lindex, lrange, lpush, ltrim, etc).
|
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 (scard, sdiff, sadd, sunion, etc).
|
Count |
SetTypeCmds |
The total number of write types of commands. This is derived from the Redis commandstats statistic by summing all of the
mutative types of commands that operate on data
(set, hset, sadd, lpop, 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 (zcount, zrange, zrank, zadd, etc).
|
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 (strlen, setex, setrange, etc).
|
Count |
StreamBasedCmds |
The total number of commands that are stream-based. This is derived from the Redis
commandstats statistic by summing all
of the commands that act upon one or more streams data types (xrange, xlen, xadd, xdel, etc).
|
Count |
