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Amazon Redshift
Management Guide (API Version 2012-12-01)

Summary of Amazon Redshift Performance Data

Amazon Redshift CloudWatch Metrics

Amazon Redshift CloudWatch metrics enable you to get information about your cluster's health and performance, and to drill down and see that information at the node level. When working with these metrics, you should keep in mind that each metric has one or more dimensions associated with it that tell you what the metric is applicable to, that is the scope of the metric. Amazon Redshift has the following two dimensions:

  • Metrics that have a NodeID dimension are metrics that provide performance data for nodes of a cluster. This includes leader and compute nodes. Examples of these metrics include CPUUtilization, ReadIOPS, WriteIOPS.

  • Metrics that have just a ClusterIdentifier dimension are metrics that provide performance data for clusters. Examples of these metrics include HealthStatus and MaintenanceMode.

    Note

    In some metric cases, a cluster-specific metric represents an aggregation of node behavior and care must be taken in the interpretation of the metric value because the leader node's behavior is aggregated with the compute node.

For more information about Amazon CloudWatch metrics and dimensions, go to Amazon CloudWatch Concepts in the Amazon CloudWatch User Guide.

The following table describes all the metrics available for you to use.

Amazon Redshift Metrics

The AWS/Redshift namespace includes the following metrics.

Metric Description
CPUUtilization

The percentage of CPU utilization. For clusters, this metric represents an aggregation of all nodes (leader and compute) CPU utilization values.

Units: Percent

Dimensions: NodeID, ClusterIdentifier

DatabaseConnections

The number of database connections to a cluster.

Units: Count

Dimensions: ClusterIdentifier

HealthStatus

Indicates the health of the cluster. Every minute the cluster connects to its database and performs a simple query. If it is able to perform this operation successfully, the cluster is considered healthy. Otherwise, the cluster is unhealthy. An unhealthy status can occur when the cluster database is under extremely heavy load or if there is a configuration problem with a database on the cluster. The exception to this is when the cluster is undergoing maintenance. Even though your cluster might be unavailable due to maintenance tasks, the cluster remains in HEALTHY state. For more information, see Maintenance Windows in the Amazon Redshift Cluster Management Guide.

Note

In Amazon CloudWatch this metric is reported as 1 or 0 whereas in the Amazon Redshift console, this metric is displayed with the words HEALTHY or UNHEALTHY for convenience. When this metric is displayed in the Amazon Redshift console, sampling averages are ignored and only HEALTHY or UNHEALTHY are displayed. In Amazon CloudWatch, values different than 1 and 0 may occur because of sampling issue. Any value below 1 for HealthStatus is reported as 0 (UNHEALTHY).

Units: 1/0 (HEALTHY/UNHEALTHY in the Amazon Redshift console)

Dimensions: ClusterIdentifier

MaintenanceMode

Indicates whether the cluster is in maintenance mode.

Note

In Amazon CloudWatch this metric is reported as 1 or 0 whereas in the Amazon Redshift console, this metric is displayed with the words ON or OFF for convenience. When this metric is displayed in the Amazon Redshift console, sampling averages are ignored and only ON or OFF are displayed. In Amazon CloudWatch, values different than 1 and 0 may occur because of sampling issues. Any value greater than 0 for MaintenanceMode is reported as 1 (ON).

Units: 1/0 (ON/OFF in the Amazon Redshift console).

Dimensions: ClusterIdentifier

NetworkReceiveThroughput

The rate at which the node or cluster receives data.

Units: Bytes/seconds (MB/s in the Amazon Redshift console)

Dimensions: NodeID, ClusterIdentifier

NetworkTransmitThroughput

The rate at which the node or cluster writes data.

Units: Bytes/second (MB/s in the Amazon Redshift console)

Dimensions: NodeID, ClusterIdentifier

PercentageDiskSpaceUsed

The percent of disk space used.

Units: Percent

Dimensions: NodeID, ClusterIdentifier

ReadIOPS

The average number of disk read operations per second.

Units: Count/second

Dimensions: NodeID

ReadLatency

The average amount of time taken for disk read I/O operations.

Units: Seconds

Dimensions: NodeID

ReadThroughput

The average number of bytes read from disk per second.

Units: Bytes (GB/s in the Amazon Redshift console)

Dimensions: NodeID

WriteIOPS

The average number of write operations per second.

Units: Count/seconds

Dimensions: NodeID

WriteLatency

The average amount of time taken for disk write I/O operations.

Units: Seconds

Dimensions: NodeID

WriteThroughput

The average number of bytes written to disk per second.

Units: Bytes (GB/s in the Amazon Redshift console)

Dimensions: NodeID

Amazon Redshift Query/Load Performance Data

In addition to the Amazon CloudWatch metrics, Amazon Redshift provides query and load performance data. Query and load performance data can be used to help you understand the relation between database performance and cluster metrics. For example, if you notice that a cluster's CPU spiked, you can find the spike on the cluster CPU graph and see the queries that were running at that time. Conversely, if you are reviewing a specific query, metric data (like CPU) is displayed in context so that you can understand the query's impact on cluster metrics.

Query and load performance data are not published as Amazon CloudWatch metrics and can only be viewed in the Amazon Redshift console. Query and load performance data are generated from querying with your database's system tables (see System Tables Reference in the Amazon Redshift Developer Guide). You can also generate your own custom database performance queries, but we recommend starting with the query and load performance data presented in the console. For more information about measuring and monitoring your database performance yourself, see Managing Performance in the Amazon Redshift Developer Guide

The following table describes different aspects of query and load data you can access in the Amazon Redshift console.

Query/Load Data Description
Query summary

A list of queries in a specified time period. The list can be sorted on values such as query ID, query run time, and status. Access this data in the Queries tab of the cluster detail page.

Query Detail

Provides details on a particular query including:

  • Query properties such as the query ID, type, cluster the query was run on, and run time.

  • Details such as the status of the query and the number of errors.

  • The SQL statement that was run.

  • An explain plan if available.

  • Cluster performance data during the query execution (see Amazon Redshift CloudWatch Metrics).

Load Summary

Lists all the loads in a specified time period. The list can be sorted on values such as query ID, query run time, and status. Access this data in the Loads tab of the cluster detail page. Access this data in the Queries tab of the cluster detail page.

Load Detail

Provides details on a particular load operation including:

  • Load properties such as the query ID, type, cluster the query was run on, and run time.

  • Details such as the status of the load and the number of errors.

  • The SQL statement that was run.

  • A list of loaded files.

  • Cluster performance data during the load operation (see Amazon Redshift CloudWatch Metrics).