Amazon Athena CloudWatch Metrics connector - Amazon Athena

Amazon Athena CloudWatch Metrics connector

The Amazon Athena CloudWatch Metrics connector enables Amazon Athena to query CloudWatch Metrics data with SQL.

For information on publishing query metrics to CloudWatch from Athena itself, see Controlling costs and monitoring queries with CloudWatch metrics and events.

Prerequisites

Parameters

Use the Lambda environment variables in this section to configure the CloudWatch Metrics connector.

  • spill_bucket – Specifies the Amazon S3 bucket for data that exceeds Lambda function limits.

  • spill_prefix – (Optional) Defaults to a subfolder in the specified spill_bucket called athena-federation-spill. We recommend that you configure an Amazon S3 storage lifecycle on this location to delete spills older than a predetermined number of days or hours.

  • spill_put_request_headers – (Optional) A JSON encoded map of request headers and values for the Amazon S3 putObject request that is used for spilling (for example, {"x-amz-server-side-encryption" : "AES256"}). For other possible headers, see PutObject in the Amazon Simple Storage Service API Reference.

  • kms_key_id – (Optional) By default, any data that is spilled to Amazon S3 is encrypted using the AES-GCM authenticated encryption mode and a randomly generated key. To have your Lambda function use stronger encryption keys generated by KMS like a7e63k4b-8loc-40db-a2a1-4d0en2cd8331, you can specify a KMS key ID.

  • disable_spill_encryption – (Optional) When set to True, disables spill encryption. Defaults to False so that data that is spilled to S3 is encrypted using AES-GCM – either using a randomly generated key or KMS to generate keys. Disabling spill encryption can improve performance, especially if your spill location uses server-side encryption.

The connector also supports AIMD congestion control for handling throttling events from CloudWatch through the Amazon Athena Query Federation SDK ThrottlingInvoker construct. You can tweak the default throttling behavior by setting any of the following optional environment variables:

  • throttle_initial_delay_ms – The initial call delay applied after the first congestion event. The default is 10 milliseconds.

  • throttle_max_delay_ms – The maximum delay between calls. You can derive TPS by dividing it into 1000ms. The default is 1000 milliseconds.

  • throttle_decrease_factor – The factor by which Athena reduces the call rate. The default is 0.5

  • throttle_increase_ms – The rate at which Athena decreases the call delay. The default is 10 milliseconds.

Databases and tables

The Athena CloudWatch Metrics connector maps your namespaces, dimensions, metrics, and metric values into two tables in a single schema called default.

The metrics table

The metrics table contains the available metrics as uniquely defined by a combination of namespace, set, and name. The metrics table contains the following columns.

  • namespace – A VARCHAR containing the namespace.

  • metric_name – A VARCHAR containing the metric name.

  • dimensions – A LIST of STRUCT objects composed of dim_name (VARCHAR) and dim_value (VARCHAR).

  • statistic – A LIST of VARCH statistics (for example, p90, AVERAGE, ...) available for the metric.

The metric_samples table

The metric_samples table contains the available metric samples for each metric in the metrics table. The metric_samples table contains the following columns.

  • namespace – A VARCHAR that contains the namespace.

  • metric_name – A VARCHAR that contains the metric name.

  • dimensions – A LIST of STRUCT objects composed of dim_name (VARCHAR) and dim_value (VARCHAR).

  • dim_name – A VARCHAR convenience field that you can use to easily filter on a single dimension name.

  • dim_value – A VARCHAR convenience field that you can use to easily filter on a single dimension value.

  • period – An INT field that represents the "period" of the metric in seconds (for example, a 60 second metric).

  • timestamp – A BIGINT field that represents the epoch time in seconds that the metric sample is for.

  • value – A FLOAT8 field that contains the value of the sample.

  • statistic – A VARCHAR that contains the statistic type of the sample (for example, AVERAGE or p90).

Required Permissions

For full details on the IAM policies that this connector requires, review the Policies section of the athena-cloudwatch-metrics.yaml file. The following list summarizes the required permissions.

  • Amazon S3 write access – The connector requires write access to a location in Amazon S3 in order to spill results from large queries.

  • Athena GetQueryExecution – The connector uses this permission to fast-fail when the upstream Athena query has terminated.

  • CloudWatch Metrics ReadOnly – The connector uses this permission to query your metrics data.

  • CloudWatch Logs Write – The connector uses this access to write its diagnostic logs.

Performance

The Athena CloudWatch Metrics connector attempts to optimize queries against CloudWatch Metrics by parallelizing scans of the log streams required for your query. For certain time period, metric, namespace, and dimension filters, predicate pushdown is performed both within the Lambda function and within CloudWatch Logs.

License information

The Amazon Athena CloudWatch Metrics connector project is licensed under the Apache-2.0 License.

See also

For additional information about this connector, visit the corresponding site on GitHub.com.