Retrieve custom metrics with StatsD - Amazon CloudWatch
Viewing StatsD metrics imported by the CloudWatch agent

Retrieve custom metrics with StatsD

You can retrieve additional custom metrics from your applications or services using the CloudWatch agent with the StatsD protocol. StatsD is a popular open-source solution that can gather metrics from a wide variety of applications. StatsD is especially useful for instrumenting your own metrics. For an example of using the CloudWatch agent and StatsD together, see How to better monitor your custom application metrics using Amazon CloudWatch Agent.

StatsD is supported on both Linux servers and servers running Windows Server. CloudWatch supports the following StatsD format:

MetricName:value|type|@sample_rate|#tag1:
  value,tag1...

  • MetricName – A string with no colons, bars, # characters, or @ characters.

  • value – This can be either integer or float.

  • type – Specify c for counter, g for gauge, ms for timer, h for histogram, or s for set.

  • sample_rate – (Optional) A float between 0 and 1, inclusive. Use only for counter, histogram, and timer metrics. The default value is 1 (sampling 100% of the time).

  • tags – (Optional) A comma-separated list of tags. StatsD tags are similar to dimensions in CloudWatch. Use colons for key/value tags, such as env:prod.

You can use any StatsD client that follows this format to send the metrics to the CloudWatch agent. For more information about some of the available StatsD clients, see the StatsD client page on GitHub.

To collect these custom metrics, add a "statsd": {} line to the metrics_collected section of the agent configuration file. You can add this line manually. If you use the wizard to create the configuration file, it's done for you. For more information, see Create the CloudWatch agent configuration file.

The StatsD default configuration works for most users. There are optional fields that you can add to the statsd section of the agent configuration file as needed:

  • service_address – The service address to which the CloudWatch agent should listen. The format is ip:port. If you omit the IP address, the agent listens on all available interfaces. Only the UDP format is supported, so you don't need to specify a UDP prefix.

    The default value is :8125.

  • metrics_collection_interval – How often in seconds that the StatsD plugin runs and collects metrics. The default value is 10 seconds. The range is 1–172,000.

  • metrics_aggregation_interval – How often in seconds CloudWatch aggregates metrics into single data points. The default value is 60 seconds.

    For example, if metrics_collection_interval is 10 and metrics_aggregation_interval is 60, CloudWatch collects data every 10 seconds. After each minute, the six data readings from that minute are aggregated into a single data point, which is sent to CloudWatch.

    The range is 0–172,000. Setting metrics_aggregation_interval to 0 disables the aggregation of StatsD metrics.

  • allowed_pending_messages – The number of UDP messages that are allowed to queue up. When the queue is full, the StatsD server starts dropping packets. The default value is 10000.

  • drop_original_metrics – Optional. If you are using the aggregation_dimensions field in the metrics section to roll up metrics into aggregated results, then by default the agent sends both the aggregated metrics and the original metrics that are separated for each value of the dimension. If you don't want the original metrics to be sent to CloudWatch, you can specify this parameter with a list of metrics. The metrics specified along with this parameter don't have their metrics by dimension reported to CloudWatch. Instead, only the aggregated metrics are reported. This reduces the number of metrics that the agent collects, reducing your costs.

The following is an example of the statsd section of the agent configuration file, using the default port and custom collection and aggregation intervals.

{
   "metrics":{
      "metrics_collected":{
         "statsd":{
            "service_address":":8125",
            "metrics_collection_interval":60,
            "metrics_aggregation_interval":300
         }
      }
   }
}

Viewing StatsD metrics imported by the CloudWatch agent

After importing StatsD metrics into CloudWatch, you can view these metrics as time series graphs, and create alarms that can watch these metrics and notify you if they breach a threshold that you specify. The following procedure shows how to view StatsD metrics as a time series graph. For more information about setting alarms, see Using Amazon CloudWatch alarms.

To view StatsD metrics in the CloudWatch console

  1. Open the CloudWatch console at https://console.aws.amazon.com/cloudwatch/.

  2. In the navigation pane, choose Metrics.

  3. Choose the namespace for the metrics collected by the agent. By default, this is CWAgent, but you may have specified a different namespace in the CloudWatch agent configuration file.

  4. Choose a metric dimension (for example, Per-Instance Metrics).

  5. The All metrics tab displays all metrics for that dimension in the namespace. You can do the following:

    1. To graph a metric, select the check box next to the metric. To select all metrics, select the check box in the heading row of the table.

    2. To sort the table, use the column heading.

    3. To filter by resource, choose the resource ID and then choose Add to search.

    4. To filter by metric, choose the metric name and then choose Add to search.

  6. (Optional) To add this graph to a CloudWatch dashboard, choose Actions, Add to dashboard.