Enabling Metrics for the |sdk-java|
The |sdk-java| can generate metrics for visualization and monitoring with |cw|_ that measure:
- your application’s performance when accessing AWS
- the performance of your JVMs when used with AWS
- runtime environment details such as heap memory, number of threads, and opened file descriptors
Note
The AWS SDK Metrics for Enterprise Support is another option for gathering metrics about your application. SDK Metrics is an |AWS| service that publishes data to |CWlong| and enables you to share metric data with AWS Support for easier troubleshooting. See :doc:`sdk-metrics` to learn how to enable the SDK Metrics service for your application.
How to Enable |sdk-java| Metric Generation
|sdk-java| metrics are disabled by default. To enable it for your local development environment, include a system property that points to your AWS security credential file when starting up the JVM. For example:
-Dcom.amazonaws.sdk.enableDefaultMetrics=credentialFile=/path/aws.properties
You need to specify the path to your credential file so that the SDK can upload the gathered datapoints to |cw| for later analysis.
Note
If you are accessing AWS from an |ec2| instance using the |ec2| instance metadata service, you don’t need to specify a credential file. In this case, you need only specify:
-Dcom.amazonaws.sdk.enableDefaultMetrics
All metrics captured by the SDK for Java are under the namespace AWSSDK/Java, and are uploaded
to the |cw| default region (us-east-1). To change the region, specify it by using the
cloudwatchRegion attribute in the system property. For example, to set the |cw| region to
us-west-2, use:
-Dcom.amazonaws.sdk.enableDefaultMetrics=credentialFile=/path/aws.properties,cloudwatchRegion=us-west-2
Once you enable the feature, every time there is a service request to AWS from the |sdk-java|, metric data points will be generated, queued for statistical summary, and uploaded asynchronously to |cw| about once every minute. Once metrics have been uploaded, you can visualize them using the |console|_ and set alarms on potential problems such as memory leakage, file descriptor leakage, and so on.
The default set of metrics is divided into three major categories:
- AWS Request Metrics
Covers areas such as the latency of the HTTP request/response, number of requests, exceptions, and retries.
- AWS Service Metrics
Include AWS service-specific data, such as the throughput and byte count for S3 uploads and downloads.
- Machine Metrics
Cover the runtime environment, including heap memory, number of threads, and open file descriptors.
If you want to exclude Machine Metrics, add
excludeMachineMetricsto the system property:-Dcom.amazonaws.sdk.enableDefaultMetrics=credentialFile=/path/aws.properties,excludeMachineMetrics
- See the :aws-java-class:`amazonaws/metrics package summary <metrics/package-summary>` for a full list of the predefined core metric types.
- Learn about working with |cw| using the |sdk-java| in :doc:`examples-cloudwatch`.
- Learn more about performance tuning in :blog:`Tuning the AWS SDK for Java to Improve Resiliency <developer/tuning-the-aws-sdk-for-java-to-improve-resiliency>` blog post.