Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Collect network performance metrics

EC2 instances running on Linux that use the Elastic Network Adapter (ENA) publish network performance metrics. Version 1.246396.0 and later of the CloudWatch agent enable you to import these network performance metrics into CloudWatch. When you import these network performance metrics into CloudWatch, they are charged as CloudWatch custom metrics.

For more information about the ENA driver, see Enabling enhanced networking with the Elastic Network Adapter (ENA) on Linux instances and Enabling enhanced networking with the Elastic Network Adapter (ENA) on Windows instances.

How you set up the collection of network performance metrics differs on Linux servers and Windows servers.

The following table lists these network performance metrics enabled by the ENA adapter. When the CloudWatch agent imports these metrics into CloudWatch from Linux instances, it prepends ethtool_ at the beginning of each of these metric names.

Linux setup

On Linux servers, the ethtool plugin enables you to import the network performance metrics into CloudWatch.

ethtool is a standard Linux utility that can collect statistics about Ethernet devices on Linux servers. The statistics it collects depend on the network device and driver. Examples of these statistics include tx_cnt, rx_bytes, tx_errors, and align_errors. When you use the ethtool plugin with the CloudWatch agent, you can also import these statistics into CloudWatch, along with the EC2 network performance metrics listed earlier in this section.

When the CloudWatch agent imports metrics into CloudWatch, it adds an ethtool_ prefix to the names of all imported metrics. So the standard ethtool statistic rx_bytes is called ethtool_rx_bytes in CloudWatch, and the EC2 network performance metric bw_in_allowance_exceeded is called ethtool_bw_in_allowance_exceeded in CloudWatch.

On Linux servers, to import ethtool metrics, add an ethtool section to the metrics_collected section of the CloudWatch agent configuration file. The ethtool section can include the following subsections:

The following example displays part of the CloudWatch agent configuration file. This configuration collects the standard ethtool metrics rx_packets and tx_packets, and the Amazon EC2 network performance metrics from only the eth1 interface.

For more information about the CloudWatch agent configuration file, see Manually create or edit the CloudWatch agent configuration file.

"metrics": {
    "append_dimensions": {
      "InstanceId": "${aws:InstanceId}"
    },
    "metrics_collected": {
      "ethtool": {
        "interface_include": [
          "eth1"
        ],
        "metrics_include": [
          "rx_packets",
          "tx_packets",
          "bw_in_allowance_exceeded",
          "bw_out_allowance_exceeded",
          "conntrack_allowance_exceeded",
          "linklocal_allowance_exceeded",
          "pps_allowance_exceeded"
         ]
      }
   }
}

Windows setup

On Windows servers, the network performance metrics are available through Windows Performance Counters, which the CloudWatch agent already collects metrics from. So you do not need a plugin to collect these metrics from Windows servers.

The following is a sample configuration file to collect network performance metrics from Windows. For more information about editing the CloudWatch agent configuration file, see Manually create or edit the CloudWatch agent configuration file.

{
    "metrics": {
        "append_dimensions": {
            "InstanceId": "${aws:InstanceId}"
        },
        "metrics_collected": {
            "ENA Packets Shaping": {
                "measurement": [
                    "Aggregate inbound BW allowance exceeded",
                    "Aggregate outbound BW allowance exceeded",
                    "Connection tracking allowance exceeded",
                    "Link local packet rate allowance exceeded",
                    "PPS allowance exceeded"
                ],
                "metrics_collection_interval": 60,
                "resources": [
                    "*"
                ]
            }
        }
    }
}

Viewing network performance metrics

After importing network performance 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 ethtool metrics as a time series graph. For more information about setting alarms, see Using Amazon CloudWatch alarms.

Because all of these metrics are aggregate counters, you can use CloudWatch metric math functions such as RATE(METRICS()) to calculate the rate for these metrics in graphs or use them to set alarms. For more information about metric math functions, see Using math expressions with CloudWatch metrics.