Publishes metric data points to Amazon CloudWatch. Amazon Cloudwatch associates the data points with the specified metric. If the specified metric does not exist, Amazon CloudWatch creates the metric.

NOTE: If you create a metric with the PutMetricData action, allow up to fifteen minutes for the metric to appear in calls to the ListMetrics action.

The size of a PutMetricData request is limited to 8 KB for HTTP GET requests and 40 KB for HTTP POST requests.

IMPORTANT: Although the Value parameter accepts numbers of type Double, Amazon CloudWatch truncates values with very large exponents. Values with base-10 exponents greater than 126 (1 x 10^126) are truncated. Likewise, values with base-10 exponents less than -130 (1 x 10^-130) are also truncated.