CloudWatch receives metrics observations and forwards them to CloudWatch. Create a CloudWatch object, use it to create metrics, and pass those metrics as dependencies to the components that will use them.
To regularly report metrics to CloudWatch, use the WriteLoop helper method.
type CloudWatch struct {
// contains filtered or unexported fields
}
func New(namespace string, svc CloudWatchAPI, options ...Option) *CloudWatch
New returns a CloudWatch object that may be used to create metrics. Namespace is applied to all created metrics and maps to the CloudWatch namespace. Callers must ensure that regular calls to Send are performed, either manually or with one of the helper methods.
func (cw *CloudWatch) NewCounter(name string) metrics.Counter
NewCounter returns a counter. Observations are aggregated and emitted once per write invocation.
func (cw *CloudWatch) NewGauge(name string) metrics.Gauge
NewGauge returns an gauge. Under the covers, there is no distinctions in CloudWatch for how Counters/Histograms/Gauges are reported, so this just wraps a cloudwatch2.Counter.
func (cw *CloudWatch) NewHistogram(name string) metrics.Histogram
NewHistogram returns a histogram. Under the covers, there is no distinctions in CloudWatch for how Counters/Histograms/Gauges are reported, so this just wraps a cloudwatch2.Counter.
func (cw *CloudWatch) Send() error
Send will fire an API request to CloudWatch with the latest stats for all metrics. It is preferred that the WriteLoop method is used.
func (cw *CloudWatch) WriteLoop(ctx context.Context, c <-chan time.Time)
WriteLoop is a helper method that invokes Send every time the passed channel fires. This method blocks until ctx is canceled, so clients probably want to run it in its own goroutine. For typical usage, create a time.Ticker and pass its C channel to this method.
CloudWatchAPI is an interface that defines the set of Amazon CloudWatch API operations required by CloudWatch.
type CloudWatchAPI interface {
PutMetricData(ctx context.Context, params *cloudwatch.PutMetricDataInput, optFns ...func(*cloudwatch.Options)) (*cloudwatch.PutMetricDataOutput, error)
}
Counter is a counter. Observations are forwarded to a node object, and aggregated per timeseries.
type Counter struct {
// contains filtered or unexported fields
}
func (c *Counter) Add(delta float64)
Add implements metrics.Counter.
func (c *Counter) With(labelValues ...string) metrics.Counter
With implements metrics.Counter.
Option is a function adapter to change config of the CloudWatch struct
type Option func(*CloudWatch)
func WithConcurrentRequests(n int) Option
WithConcurrentRequests sets the upper limit on how many cloudwatch.PutMetricDataRequest may be under way at any given time. If n is greater than 20, 20 is used. By default, the max is set at 10 concurrent requests.
func WithLogger(logger log.Logger) Option
WithLogger sets the Logger that will receive error messages generated during the WriteLoop. By default, no logger is used.