17.1.1 CloudWatch Monitoring Metrics

CloudWatch metrics can be used to monitor resources, diagnose issues, and troubleshoot your DB systems and their HeatWave Clusters. After enabling CloudWatch monitoring on a DB System, you can select the set of metrics that will be emitted to CloudWatch for the DB System and its HeatWave Cluster.

The metrics are emitted using the CloudWatch embedded metric format (EMF) logs. The EMF logs are JSON objects that embed metric data along with metadata and contextual information. You can find more information about the EMF format in EMF specification by AWS. Here is a sample EMF log snippet:

{
    "_aws": {
        "CloudWatchMetrics": [
            {
                "Namespace": "OracleHeatWave",
                "Dimensions": [
                    [
                        "dbSystemId"
                    ]
                ],
                "Metrics": [
                    {
                        "Name": "mysql.stats.threads_connected",
                        "Unit": "Count",
                        "StorageResolution": 60
                    }
                ]
            }
        ],
        "Timestamp": 1750074660311
    },
    "dbSystemId": "example-dbsystem-id",
    "mysql.stats.threads_connected": 1
}

Here are explanations for some of the objects in an EMF log:

• Namespace: Metrics are emitted to the OracleHeatWave namespace in CloudWatch. The EMF logs are streamed to the /OracleHeatWave/metrics log group.
• Dimensions:
  • dbSystemId: Specifies the unique ID of the DB System.
  • resourceType: Specifies the resource type the metric originated from. It can be one of:
    • mysql: DB System
    • heatWave: HeatWave Cluster
  • heatWaveNode: Specifies the HeatWave node index the metric originated from.

• Metrics: Table 17-1 list the metrics for monitoring your DB Systems and HeatWave Clusters.

  Metrics included in the Basic metric template in the Monitoring Configurations are marked by a * beside their names in the table. All the listed metrics are included in the Detailed metric template.

  Table 17-1 CloudWatch Metrics for HeatWave on AWS

  Metric	Unit	Description	Dimensions
  heatwave.auto_ml_operation_count	Count	The number of AutoML operations that have been executed. This number resets on HeatWave restart.	dbSystemId
  heatwave.change_propagation_lag	Count	The number of transactions that are not propagated to HeatWave yet.	dbSystemId
  heatwave.dataset_bytes	Bytes	The amount of data loaded in the HeatWave cluster.	dbSystemId
  heatwave.heap_usage	Bytes	The size of the HeatWave data dictionary, which consumes heap space on the DB system nodes.	dbSystemId
  heatwave.lakehouse_total_loaded_bytes	Bytes	The total size of all Lakehouse tables loaded into HeatWave.	dbSystemId
  heatwave.loaded_tables_available	Count	The total size of all Lakehouse tables loaded into HeatWave.	dbSystemId
  heatwave.loaded_tables_unusable	Count	The number of tables loaded into HeatWave that are currently not available for use.	dbSystemId
  heatwave.health*	Count	HeatWave cluster health status.	dbSystemId
  heatwave.load_progress*	Percent	Progress of data load into HeatWave cluster memory.	dbSystemId
  heatwave.query_offload_count*	Count	The number of statements executed against the DB System and were executed on HeatWave cluster.	dbSystemId
  mysql.inno.buffer_pool.pages_dirty	Count	Buffer pages currently dirty.	dbSystemId
  mysql.inno.buffer_pool.pages_free	Count	Buffer pages currently free.	dbSystemId
  mysql.inno.buffer_pool.pages_total	Count	Total buffer pool size in pages.	dbSystemId
  mysql.stats.aborted_clients	Count	The number of connections that were aborted because the client died without closing the connection properly.	dbSystemId
  mysql.stats.aborted_connects	Count	The number of failed attempts to connect to the MySQL server.	dbSystemId
  mysql.stats.connection.total	Count	Cumulative count of total connections created.	dbSystemId
  mysql.stats.created.tmp_disk_tables	Count	The number of internal on-disk temporary tables created by the server while executing statements.	dbSystemId
  mysql.stats.created.tmp_tables	Count	The number of internal temporary tables created by the server while executing statements.	dbSystemId
  mysql.stats.handler.delete	Count	The number of times that rows have been deleted from tables.	dbSystemId
  mysql.stats.handler.read_first	Count	The number of times the first entry in an index was read.	dbSystemId
  mysql.stats.handler.read_key	Count	The number of requests to read a row based on a key.	dbSystemId
  mysql.stats.handler.read_last	Count	The number of requests to read the last key in an index.	dbSystemId
  mysql.stats.handler.read_next	Count	The number of requests to read the next row in key order.	dbSystemId
  mysql.stats.handler.read_prev	Count	The number of requests to read the previous row in key order.	dbSystemId
  mysql.stats.handler.read_rnd	Count	The number of requests to read a row based on a fixed position.	dbSystemId
  mysql.stats.handler.read_rnd_next	Count	The number of requests to read the next row in the data file.	dbSystemId
  mysql.stats.handler.update	Count	The number of requests to update a row in a table.	dbSystemId
  mysql.stats.handler.write	Count	The number of requests to insert a row in a table.	dbSystemId
  mysql.stats.select_full_join	Count	The number of joins that perform table scans because they do not use indexes.	dbSystemId
  mysql.stats.select_full_range_join	Count	The number of joins that used a range search on a reference table.	dbSystemId
  mysql.stats.select_range	Count	The number of joins that used ranges on the first table.	dbSystemId
  mysql.stats.select_range_check	Count	The number of joins without keys that check for key usage after each row.	dbSystemId
  mysql.stats.select_scan	Count	The number of joins that did a full scan of the first table.	dbSystemId
  mysql.stats.sort_merge_passes	Count	The number of merge passes that the sort algorithm has had to do.	dbSystemId
  mysql.stats.sort_range	Count	The number of sorts that were done using ranges.	dbSystemId
  mysql.stats.sort_rows	Count	The number of sorted rows.	dbSystemId
  mysql.stats.sort_scan	Count	The number of sorts that were done by scanning the table.	dbSystemId
  mysql.stats.threads_connected*	Count	The number of current connections to the DB system.	dbSystemId
  mysql.stats.threads_running*	Count	The number of connections actively executing statements against the DB system.	dbSystemId
  system.cpu.utilization*	Percent	The CPU utilization for the DB system host.	dbSystemId resourceType
  system.dbvolume.utilization*	Percent	The total space utilization of the DB System volume.	dbSystemId resourceType
  system.dbvolume.size*	Bytes	The maximum amount of space allocated to the DB System during the interval.	dbSystemId resourceType
  system.dbvolume.usage*	Bytes	The maximum amount of space used during the interval.	dbSystemId resourceType
  system.memory.utilization*	Percent	Memory utilization for the DB System host.	dbSystemId resourceType heatWaveNode
  system.memory.size*	Bytes	The total amount of memory allocated during the selected interval.	dbSystemId resourceType heatWaveNode
  system.memory.usage*	Bytes	The maximum amount of memory used during the selected interval.	dbSystemId resourceType heatWaveNode

How metrics are sent:

• Metrics are emitted every 60 seconds.
• During maintenance or actions against the DB System (for example, restart, update), metric emissions might be interrupted.
• Metrics for highly available DB Systems are only emitted for the primary instance; secondary instances do not emit metrics. In case of a loss of quorum when both secondaries are unreachable (for example, due to network partitioning), no metrics will be sent until majority is restored for the DB System.