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Amazon CloudWatch Statistics Input Plugin

This plugin will pull Metric Statistics from Amazon CloudWatch.

Amazon Authentication

This plugin uses a credential chain for Authentication with the CloudWatch API endpoint. In the following order the plugin will attempt to authenticate.

  1. Assumed credentials via STS if role_arn attribute is specified (source credentials are evaluated from subsequent rules)
  2. Explicit credentials from access_key, secret_key, and token attributes
  3. Shared profile from profile attribute
  4. Environment Variables
  5. Shared Credentials
  6. EC2 Instance Profile

Configuration:

# Pull Metric Statistics from Amazon CloudWatch
[[inputs.cloudwatch]]
  ## Amazon Region
  region = "us-east-1"

  ## Amazon Credentials
  ## Credentials are loaded in the following order
  ## 1) Web identity provider credentials via STS if role_arn and web_identity_token_file are specified
  ## 2) Assumed credentials via STS if role_arn is specified
  ## 3) explicit credentials from 'access_key' and 'secret_key'
  ## 4) shared profile from 'profile'
  ## 5) environment variables
  ## 6) shared credentials file
  ## 7) EC2 Instance Profile
  #access_key = ""
  #secret_key = ""
  #token = ""
  #role_arn = ""
  #web_identity_token_file = ""
  #role_session_name = ""
  #profile = ""
  #shared_credential_file = ""

  ## Endpoint to make request against, the correct endpoint is automatically
  ## determined and this option should only be set if you wish to override the
  ## default.
  ##   ex: endpoint_url = "http://localhost:8000"
  # endpoint_url = ""

  ## Set http_proxy (telegraf uses the system wide proxy settings if it's is not set)
  # http_proxy_url = "http://localhost:8888"

  # The minimum period for Cloudwatch metrics is 1 minute (60s). However not all
  # metrics are made available to the 1 minute period. Some are collected at
  # 3 minute, 5 minute, or larger intervals. See https://aws.amazon.com/cloudwatch/faqs/#monitoring.
  # Note that if a period is configured that is smaller than the minimum for a
  # particular metric, that metric will not be returned by the Cloudwatch API
  # and will not be collected by Telegraf.
  #
  ## Requested CloudWatch aggregation Period (required - must be a multiple of 60s)
  period = "5m"

  ## Collection Delay (required - must account for metrics availability via CloudWatch API)
  delay = "5m"

  ## Recommended: use metric 'interval' that is a multiple of 'period' to avoid
  ## gaps or overlap in pulled data
  interval = "5m"

  ## Recommended if "delay" and "period" are both within 3 hours of request time. Invalid values will be ignored.
  ## Recently Active feature will only poll for CloudWatch ListMetrics values that occurred within the last 3 Hours.
  ## If enabled, it will reduce total API usage of the CloudWatch ListMetrics API and require less memory to retain.
  ## Do not enable if "period" or "delay" is longer than 3 hours, as it will not return data more than 3 hours old.
  ## See https://docs.aws.amazon.com/AmazonCloudWatch/latest/APIReference/API_ListMetrics.html
  #recently_active = "PT3H"

  ## Configure the TTL for the internal cache of metrics.
  # cache_ttl = "1h"

  ## Metric Statistic Namespaces (required)
  namespaces = ["AWS/ELB"]
  # A single metric statistic namespace that will be appended to namespaces on startup
  # namespace = "AWS/ELB"

  ## Maximum requests per second. Note that the global default AWS rate limit is
  ## 50 reqs/sec, so if you define multiple namespaces, these should add up to a
  ## maximum of 50.
  ## See http://docs.aws.amazon.com/AmazonCloudWatch/latest/monitoring/cloudwatch_limits.html
  # ratelimit = 25

  ## Timeout for http requests made by the cloudwatch client.
  # timeout = "5s"

  ## Namespace-wide statistic filters. These allow fewer queries to be made to
  ## cloudwatch.
  # statistic_include = [ "average", "sum", "minimum", "maximum", sample_count" ]
  # statistic_exclude = []

  ## Metrics to Pull
  ## Defaults to all Metrics in Namespace if nothing is provided
  ## Refreshes Namespace available metrics every 1h
  #[[inputs.cloudwatch.metrics]]
  #  names = ["Latency", "RequestCount"]
  #
  #  ## Statistic filters for Metric.  These allow for retrieving specific
  #  ## statistics for an individual metric.
  #  # statistic_include = [ "average", "sum", "minimum", "maximum", sample_count" ]
  #  # statistic_exclude = []
  #
  #  ## Dimension filters for Metric.  All dimensions defined for the metric names
  #  ## must be specified in order to retrieve the metric statistics.
  #  ## 'value' has wildcard / 'glob' matching support such as 'p-*'.
  #  [[inputs.cloudwatch.metrics.dimensions]]
  #    name = "LoadBalancerName"
  #    value = "p-example"

Requirements and Terminology

Plugin Configuration utilizes CloudWatch concepts and access pattern to allow monitoring of any CloudWatch Metric.

  • region must be a valid AWS Region value
  • period must be a valid CloudWatch Period value
  • namespace must be a valid CloudWatch Namespace value
  • names must be valid CloudWatch Metric names
  • dimensions must be valid CloudWatch Dimension name/value pairs

Omitting or specifying a value of '*' for a dimension value configures all available metrics that contain a dimension with the specified name to be retrieved. If specifying >1 dimension, then the metric must contain all the configured dimensions where the the value of the wildcard dimension is ignored.

Example:

[[inputs.cloudwatch]]
  period = "1m"
  interval = "5m"

  [[inputs.cloudwatch.metrics]]
    names = ["Latency"]

    ## Dimension filters for Metric (optional)
    [[inputs.cloudwatch.metrics.dimensions]]
      name = "LoadBalancerName"
      value = "p-example"

    [[inputs.cloudwatch.metrics.dimensions]]
      name = "AvailabilityZone"
      value = "*"

If the following ELBs are available:

  • name: p-example, availabilityZone: us-east-1a
  • name: p-example, availabilityZone: us-east-1b
  • name: q-example, availabilityZone: us-east-1a
  • name: q-example, availabilityZone: us-east-1b

Then 2 metrics will be output:

  • name: p-example, availabilityZone: us-east-1a
  • name: p-example, availabilityZone: us-east-1b

If the AvailabilityZone wildcard dimension was omitted, then a single metric (name: p-example) would be exported containing the aggregate values of the ELB across availability zones.

To maximize efficiency and savings, consider making fewer requests by increasing interval but keeping period at the duration you would like metrics to be reported. The above example will request metrics from Cloudwatch every 5 minutes but will output five metrics timestamped one minute apart.

Restrictions and Limitations

  • CloudWatch metrics are not available instantly via the CloudWatch API. You should adjust your collection delay to account for this lag in metrics availability based on your monitoring subscription level
  • CloudWatch API usage incurs cost - see GetMetricData Pricing

Measurements & Fields:

Each CloudWatch Namespace monitored records a measurement with fields for each available Metric Statistic. Namespace and Metrics are represented in snake case

  • cloudwatch_{namespace}
    • {metric}_sum (metric Sum value)
    • {metric}_average (metric Average value)
    • {metric}_minimum (metric Minimum value)
    • {metric}_maximum (metric Maximum value)
    • {metric}_sample_count (metric SampleCount value)

Tags:

Each measurement is tagged with the following identifiers to uniquely identify the associated metric Tag Dimension names are represented in snake case

  • All measurements have the following tags:
    • region (CloudWatch Region)
    • {dimension-name} (Cloudwatch Dimension value - one for each metric dimension)

Troubleshooting:

You can use the aws cli to get a list of available metrics and dimensions:

aws cloudwatch list-metrics --namespace AWS/EC2 --region us-east-1
aws cloudwatch list-metrics --namespace AWS/EC2 --region us-east-1 --metric-name CPUCreditBalance

If the expected metrics are not returned, you can try getting them manually for a short period of time:

aws cloudwatch get-metric-data \
  --start-time 2018-07-01T00:00:00Z \
  --end-time 2018-07-01T00:15:00Z \
  --metric-data-queries '[
  {
    "Id": "avgCPUCreditBalance",
    "MetricStat": {
      "Metric": {
        "Namespace": "AWS/EC2",
        "MetricName": "CPUCreditBalance",
        "Dimensions": [
          {
            "Name": "InstanceId",
            "Value": "i-deadbeef"
          }
        ]
      },
      "Period": 300,
      "Stat": "Average"
    },
    "Label": "avgCPUCreditBalance"
  }
]'

Example Output:

$ ./telegraf --config telegraf.conf --input-filter cloudwatch --test
> cloudwatch_aws_elb,load_balancer_name=p-example,region=us-east-1 latency_average=0.004810798017284538,latency_maximum=0.1100282669067383,latency_minimum=0.0006084442138671875,latency_sample_count=4029,latency_sum=19.382705211639404 1459542420000000000