Amazon CloudWatch
User Guide

Retrieve Custom Metrics with collectd

You can retrieve custom metrics from your applications or services using the CloudWatch agent with the collectd protocol. collectd is supported only on Linux servers. You use collectd software to send the metrics to the CloudWatch agent.

collectd software is not installed automatically on every server. For more information about collectd and downloading collectd software, see the Download page for collectd.

Basic configuration for collecting these custom metrics with the CloudWatch agent is to add a "collectd": {} 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 is done for you. For more information, see Create the CloudWatch Agent Configuration File.

Optional parameters are also available. If you are using collectd and you do not use /etc/collectd/auth_file as your collectd_auth_file, you must set some of these options.

  • service_address: The service address to which the CloudWatch agent should listen. The format is "udp://ip:port. The default is udp://

  • name_prefix: A prefix to attach to the beginning of the name of each collectd metric. The default is collectd_. The maximum length is 255 characters.

  • collectd_security_level: Sets the security level for network communication. The default is Encrypt.

    Encrypt specifies that only encrypted data is accepted. Sign specifies that only signed and encrypted data is accepted. None specifies that all data is accepted. If you specify a value for collectd_auth_file, encrypted data is decrypted if possible.

    For more information, see Client setup and Possible interactions in the collectd Wiki.

  • collectd_auth_file Sets a file in which user names are mapped to passwords. These passwords are used to verify signatures and to decrypt encrypted network packets. If given, signed data is verified and encrypted packets are decrypted. Otherwise, signed data is accepted without checking the signature and encrypted data cannot be decrypted.

    The default is /etc/collectd/auth_file

    If collectd_security_level is set to None, this is optional. If you set collectd_security_level to Encrypt or Sign, you must specify collectd_auth_file.

    For the format of the auth file, each line is a user name followed by a colon and any number of spaces followed by the password. For example:

    user1: user1_password

    user2: user2_password

  • collectd_typesdb: A list of one or more files that contain the dataset descriptions. The list must be surrounded by brackets, even if there is just one entry in the list. Each entry in the list must be surrounded by double quotes. If there are multiple entries, separate them with commas. The default is ["/usr/share/collectd/types.db"]. For more information, see

  • metrics_aggregation_interval: How often in seconds CloudWatch aggregates metrics into single data points. The default is 60 seconds. The range is 0 to 172,000. Setting it to 0 disables the aggregation of collectd metrics.

The following is an example of the collectd section of the agent configuration file.

{ "metrics":{ "metrics_collected":{ "collectd":{ "name_prefix":"My_collectd_metrics_", "metrics_aggregation_interval":120 } } } }