This page lists Cloud Monitoring metrics available for Memorystore for Valkey, and describes what each metric measures.
Cloud Monitoring metrics
Instance-level metrics
These metrics provide a high-level overview of the overall health and performance of the instance. They help you understand the overall capacity and utilization of the instance, as well as identify potential bottlenecks or areas for improvement.
| Metric name | Description |
|---|---|
memorystore.googleapis.com/instance/clients/average_connected_clients |
Mean current number of client connections across all nodes in the instance. |
memorystore.googleapis.com/instance/clients/maximum_connected_clients |
Maximum current number of client connections for a single node in the instance. |
memorystore.googleapis.com/instance/clients/maximum_connection_duration |
Maximum duration of a client connection for a single node in the instance. |
memorystore.googleapis.com/instance/clients/total_connected_clients |
Current number of client connectionsto the instance. |
memorystore.googleapis.com/instance/stats/total_connections_received_count |
Count of instance-level total client connections created in the last one minute. |
memorystore.googleapis.com/instance/stats/total_rejected_connections_count |
Number of connections rejected because of maxclients limit. |
memorystore.googleapis.com/instance/commandstats/total_usec_count |
The total time consumed per command. |
memorystore.googleapis.com/instance/commandstats/total_calls_count |
Total number of calls for this command in one minute. |
memorystore.googleapis.com/instance/cpu/average_utilization |
Mean CPU utilization across all nodes in the instance from 0.0 to 1.0. |
memorystore.googleapis.com/instance/cpu/maximum_utilization |
Maximum CPU utilization for a single node in the instance from 0.0 to 1.0. |
memorystore.googleapis.com/instance/stats/average_expired_keys |
Mean number of key expiration events for the primaries of all nodes in the instance. |
memorystore.googleapis.com/instance/stats/maximum_expired_keys |
Maximum number of key expiration events for a single node in the instance for the primary. |
memorystore.googleapis.com/instance/stats/total_expired_keys_count |
Total number of key expiration events across primaries of all nodes in the instance. |
memorystore.googleapis.com/instance/stats/average_evicted_keys |
Mean number of evicted keys due to memory capacity across primaries of all nodes in the instance. |
memorystore.googleapis.com/instance/stats/maximum_evicted_keys |
Maximum number of evicted keys for a single node in the instance due to memory capacity for the primary. |
memorystore.googleapis.com/instance/stats/total_evicted_keys_count |
Number of evicted keys due to memory capacity across primaries of all nodes in the instance. |
memorystore.googleapis.com/instance/keyspace/total_keys |
Number of keys stored in the instance. |
memorystore.googleapis.com/instance/stats/average_keyspace_hits |
Mean number of successful lookup of keys across all nodes in the instance. |
memorystore.googleapis.com/instance/stats/maximum_keyspace_hits |
Maximum number of successful lookup of keys for a single node in the instance. |
memorystore.googleapis.com/instance/stats/total_keyspace_hits_count |
Number of successful lookup of keys for the instance. |
memorystore.googleapis.com/instance/stats/average_keyspace_misses |
Mean number of failed lookup of keys across all nodes in the instance. |
memorystore.googleapis.com/instance/stats/maximum_keyspace_misses |
Maximum number of failed lookup of keys for a single node in the instance. |
memorystore.googleapis.com/instance/stats/total_keyspace_misses_count |
Total number of failed lookup of keys for the instance. |
memorystore.googleapis.com/instance/memory/average_utilization |
Mean memory utilization across all nodes in the instance. Value is from 0.0 to 1.0. |
memorystore.googleapis.com/instance/memory/maximum_utilization |
Maximum memory utilization for a single node in the instance from 0.0 to 1.0. |
memorystore.googleapis.com/instance/memory/total_used_memory |
Total memory usage of the instance. |
memorystore.googleapis.com/instance/memory/size |
Memory size of the instance. |
memorystore.googleapis.com/instance/replication/average_ack_lag |
Mean replication lag (in seconds) of replicas across all nodes in the instance.Replication lag (in seconds) indicates how far replicas are lagging behind primaries. |
memorystore.googleapis.com/instance/replication/maximum_ack_lag |
Maximum replication acknowledge lag (in seconds) for a single replica in the instance.Replication acknowledge lag (in seconds) indicates how far replication acknowledgements are lagging behind primaries. |
memorystore.googleapis.com/instance/replication/average_offset_diff |
Mean replication acknowledge offset diff (in bytes) across all nodes in the instance.Replication acknowledge offset diff means the number of bytes that have not been replicated between replicas and their primaries. |
memorystore.googleapis.com/instance/replication/maximum_offset_diff |
Maximum replication offset diff (in bytes) for a single node in the instance.Replication offset diff means the number of bytes that have not been replicated between a replicas and their primaries. |
memorystore.googleapis.com/instance/stats/total_net_input_bytes_count |
Count of incoming network bytes received by the instance endpoints. |
memorystore.googleapis.com/instance/stats/total_net_output_bytes_count |
Count of outgoing network bytes sent from the instance endpoints. |
Node-level metrics
These metrics offer detailed insights into the health and performance of individual nodes within the instance. They help you troubleshoot issues with nodes and optimize the performance of nodes.
| Metric name | Description |
|---|---|
memorystore.googleapis.com/instance/node/clients/connected_clients |
The number of clients connected to the instance node. |
memorystore.googleapis.com/instance/node/clients/blocked_clients |
The number of client connections that the instance node blocks. |
memorystore.googleapis.com/instance/node/server/uptime |
The uptime of the instance node. |
memorystore.googleapis.com/instance/node/stats/connections_received_count |
The number of client connections that Memorystore for Valkey creates in the last minute on the instance node. |
memorystore.googleapis.com/instance/node/stats/rejected_connections_count |
The number of connections that Memorystore for Valkey rejects because the instance node reaches the `maxclients` limit. |
memorystore.googleapis.com/instance/node/commandstats/usec_count |
The time consumed for each command in the instance node. |
memorystore.googleapis.com/instance/node/commandstats/calls_count |
The number of calls for this command on the instance node in one minute. |
memorystore.googleapis.com/instance/node/cpu/utilization |
The CPU utilization for the instance node (from 0.0 to 1.0). |
memorystore.googleapis.com/instance/node/stats/expired_keys_count |
The number of expiration events in the instance node. |
memorystore.googleapis.com/instance/node/stats/evicted_keys_count |
The number of evicted keys by the instance node. |
memorystore.googleapis.com/instance/node/keyspace/total_keys |
The number of keys that Memorystore for Valkey stores in the instance node. |
memorystore.googleapis.com/instance/node/stats/keyspace_hits_count |
The number of successful lookups of keys in the instance node. |
memorystore.googleapis.com/instance/node/stats/keyspace_misses_count |
The number of failed lookups of keys in the instance node. |
memorystore.googleapis.com/instance/node/memory/utilization |
The memory utilization for the instance node (from 0.0 to 1.0). |
memorystore.googleapis.com/instance/node/memory/usage |
The memory usage of the instance node. |
memorystore.googleapis.com/instance/node/stats/net_input_bytes_count |
The number of incoming network bytes that the instance node receives. |
memorystore.googleapis.com/instance/node/stats/net_output_bytes_count |
The number of outgoing network bytes that the instance node sends. |
memorystore.googleapis.com/instance/node/replication/offset |
The replication offset bytes of the instance node. |
Cross-region replication metrics
This section lists metrics used for cross-region replication.
| Metric name | Description |
|---|---|
memorystore.googleapis.com/instance/cross_instance_replication/secondary_replication_links |
This metric shows the number of shard links between the primary and secondary instances. Within a cross-region replication group, a primary instance reports the number of cross-region replication links that it has with the secondary instances in the group. For each secondary instance, this number is expected to be equal to the number of shards. If the number drops below the number of shards, then this metric identifies the number of shards when replication stopped between the replicator and the follower. In an ideal state, this metric has the same number as the shard count for the primary instance. |
memorystore.googleapis.com/instance/cross_instance_replication/secondary_maximum_replication_offset_diff |
This metric shows the maximum replication offset difference between the primary and secondary shards. |
memorystore.googleapis.com/instance/cross_instance_replication/secondary_average_replication_offset_diff |
This metric shows the average replication offset difference between the primary and secondary shards. |
Backup metrics
This section lists backup and import metrics.
Instance-level metrics
| Metric name | Description |
|---|---|
memorystore.googleapis.com/instance/backup/last_backup_start_time |
The start time of the last backup operation. |
memorystore.googleapis.com/instance/backup/last_backup_status |
The status of the last backup operation. Statuses are 1 (success) and 0 (failure). |
memorystore.googleapis.com/instance/backup/last_backup_duration |
The duration of the last backup operation (in milliseconds). |
memorystore.googleapis.com/instance/backup/last_backup_size |
The size of the last backup (in bytes). |
memorystore.googleapis.com/instance/import/last_import_start_time |
The start time of the last import operation. |
memorystore.googleapis.com/instance/import/last_import_duration |
The duration of the last import operation(in milliseconds). |
Persistence metrics
This section lists persistence metrics and provides sample use cases for persistence metrics.
RDB persistence metrics
Instance-level metrics
| Metric name | Description |
|---|---|
memorystore.googleapis.com/instance/persistence/load_count |
The cumulative count count of loads from across the instance for AOF or RDB persistence. |
memorystore.googleapis.com/instance/persistence/rdb_saves_count |
The cumulative number of times that your instance takes an RDB snapshot (also known as save). This metric has a status_code field. To check if a snapshot fails, you can filter the status_code field for the following error: 3 - INTERNAL ERROR. |
memorystore.googleapis.com/instance/persistence/rdb_last_success_ages |
A distribution snapshot age for all nodes across the instance. You want to see the distribution have values that have less lag time (or the same time) than your snapshot frequency. |
memorystore.googleapis.com/instance/persistence/rejected_writes_count |
The cumulative count of denied write commands across the instance because of a failure to persist. |
Node-level metrics
| Metric name | Description |
|---|---|
memorystore.googleapis.com/instance/node/persistence/rdb_bgsave_in_progress |
An RDB BGSAVE is in progress on the instance node. TRUE means that the save is in progress. |
memorystore.googleapis.com/instance/node/persistence/rdb_last_bgsave_status |
The success of the last BGSAVE on the instance node. TRUE means that a successful BGSAVE occurs. If no bgrewrite occurs. then the value might default to TRUE. |
memorystore.googleapis.com/instance/node/persistence/rdb_saves_count |
The metric shows the cumulative number of RDB saves run on the instance node. |
memorystore.googleapis.com/instance/node/persistence/rdb_last_save_age |
The time (in seconds) since the last successful snapshot. |
memorystore.googleapis.com/instance/node/persistence/rdb_next_save_time_until |
The time remaining (in seconds) until the next snapshot. |
memorystore.googleapis.com/instance/node/persistence/current_save_keys_total |
The number of keys in the RDB save that runs on the instance node. |
AOF persistence metrics
Instance-level metrics
| Metric name | Description |
|---|---|
memorystore.googleapis.com/instance/persistence/aof_fsync_lags |
This metric shows a distribution of the lag (from data write to durable storage sync) for all nodes in the instance. It is only emitted for instances with appendfsync=everysec. Ideally you want to see the distribution have values that have less lag time (or the same time) than your AOF sync frequency. |
memorystore.googleapis.com/instance/persistence/aof_rewrite_count |
This metric shows the cumulative number of times for your instance that a node has triggered an AOF rewrite. This metric has a status_code field. To check if AOF rewrites are failing, you can filter the status_code field for the following error: 3 - INTERNAL_ERROR |
Node-level metrics
| Metric name | Description |
|---|---|
memorystore.googleapis.com/instance/node/persistence/aof_last_write_status |
This metrics shows the success of the most recent AOF write on the instance node. TRUE means success, if no write has occurred the value may default to TRUE. |
memorystore.googleapis.com/instance/node/persistence/aof_last_bgrewrite_status |
This metric shows the success of the last AOF bgrewrite operation on the instance node. TRUE means success, if no bgrewrite has occurred the value may default to TRUE. |
memorystore.googleapis.com/instance/node/persistence/aof_fsync_lag |
This metric shows the AOF lag between memory and persistent store in the instance node. It is only applicable for AOF enabled instances where appendfsync=EVERYSEC |
memorystore.googleapis.com/instance/node/persistence/aof_rewrites_count |
This metric shows the count of AOF rewrites in the instance node. To check if AOF rewrites are failing, you can filter the status_code field for the following error: 3 - INTERNAL_ERROR |
memorystore.googleapis.com/instance/node/persistence/aof_fsync_errors_count |
This metric shows the count of AOF fsync() call errors and is only applicable for AOF enabled instances where appendfsync=EVERYSEC|ALWAYS. |
Common Persistence Metrics
Metrics that are applicable to both AOF and RDB persistence mechanisms.
Node level metrics
| Metric name | Description |
|---|---|
memorystore.googleapis.com/instance/node/persistence/auto_restore_count |
This metric shows the count of restores from the dumpfile (AOF or RDB). To check if restores are failing, you can filter the status_code field for the following error: 2 - INTERNAL_ERROR |
Sample use cases for persistence metrics
Checking if AOF write operations cause latency and memory pressure
Suppose that you detect increased latency or memory usage on your instance or the node within the instance. In this case you may want to check if the extra usage is related to AOF persistence.
Since you know AOF rewrite operations can trigger transient load spikes, you can inspect the aof_rewrites_count metric which gives you the cumulative count of AOF rewrites over the lifetime of the instance or the node within the instance. Suppose this metric shows you that increments in the rewrites count correspond to latency increases. In this circumstance you could address the issue by reducing the write rate or increasing the shard count to reduce the frequency of rewrites.
Checking if RDB save operations cause latency and memory pressure
Suppose that you detect increased latency or memory usage on your instance or the node within the instance. In this case you may want to check if the extra usage is related to RDB persistence.
Since you know RDB save operations can trigger transient load spikes, you can inspect the rdb_saves_count metric which gives the cumulative count of RDB saves over the lifetime of the instance or the node within the instance. Suppose this metric shows you that increments in the RDB saves count correspond to latency increases. In this circumstance you could reduce the RDB snapshot interval to lower the frequency of rewrites. You could also scale out the instance to reduce the baseline load levels.
Interpreting metrics for Memorystore for Valkey
As seen in the list above, many of the metrics share three categories: average, maximum, and total.
For Memorystore for Valkey, we provide average and maximum variations of the same metric so you can use them both to identify hotspotting for that metric family.
The total value for the metric is independent, and provides separate insight unrelated to the hotspotting purpose of average and maximum.
Understanding average and maximum metrics
Suppose you compare the average_keyspace_hits and maximum_keyspace_hits
values for your instance. As the difference between the two metrics grows, a
greater difference indicates more hot spotting of hits in your instance. Ideally
you would have a close value between average_keyspace_hits and
maximum_keyspace_hits, because this means that hits are more evenly
distributed across your instance.
This principle applies to all metrics that have the average and maximum variations of the same metric.
Hot spotting example
If you compare average_keyspace_hits and maximum_keyspace_hits for all of
the shards in your instance, comparing these values indicates where hot spotting
occurs. For example, suppose shards in a 6-shard instance have the following
number of hits:
- Shard 1 – 2 hits
- Shard 2 – 2 hits
- Shard 3 – 2 hits
- Shard 4 – 2 hits
- Shard 5 – 2 hits
- Shard 6 – 8 hits
In this example the average_keyspace_hits returns a value of 3, and the
maximum_keyspace_hits returns 8, indicating that shard 6 is hot.
We provide node level metrics which could be useful to identify hotspots within the instance.