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Log Collection Troubleshooting Guide

There are a number of common issues that can get in the way when sending new logs to Datadog via the log collector in the dd-agent. If you experience issues sending new logs to Datadog, this list helps you troubleshoot. If you continue to have trouble, email us for further assistance.

The Agent needs to be restarted

After you’ve made any configuration changes to the datadog-agent, the changes only take effect after you restart the Datadog Agent.

Outbound traffic on port 10516 is blocked

The Datadog Agent sends its logs to Datadog over tcp via port 10516. If that connection is not available, logs fail to be sent and an error is recorded in the agent.log file to that effect.

Test manually your connection by running a telnet or openssl command like so (port 10514 would work too, but is less secure):

  • openssl s_client -connect
  • telnet 10514

And then by sending a log like the following:

<API_KEY> this is a test message
  • If opening the port 10514 or 10516 is not an option, it is possible to ask the Datadog Agent to use the port 443 to forward them (only available with the Datadog Agent) by adding the following in datadog.yaml:
  use_port_443: true

No new logs have been written

The Datadog Agent only collects logs that have been written after it has started trying to collect them (whether it be tailing or listening for them). In order to confirm whether log collection has been successfully set up, make sure that new logs have been written.

Permission Issues While Tailing Log Files

The datadog-agent does not run as root (and we do not recommend that you make it run as root, as a general best-practice). For this reason, when you configure your datadog-agent to tail log files (for custom logs or for integrations) you need to take special care to ensure the datadog-agent user has read access to tail the log files you want to collect from.

If the datadog-agent user does not have read access to the files you configure it to tail, then a permissions error is captured in the /var/log/datadog/agent.log. The Agent requires to have an execute permission on the directory containing the files (this is the default permission required to be able to list the file contained in a directory).

Note: When adding the appropriate read permissions, make sure that these permissions are correctly set in your log rotation configuration. Otherwise, on the next log rotate, the Datadog Agent may lose its read permissions. Set permissions as 644 in the log rotation configuration to make sure the Agent has read access to the files.

Configuration issues

These are a few of the common configuration issues that are worth triple-checking in your datadog-agent setup:

  1. Run the Agent status config to spot the major configuration issue: datadog-agent status.

  2. Check if the api_key is defined in datadog.yaml.

  3. By default the Agent does not collect any logs, make sure there is at least one .yaml file in the Agent’s conf.d/ directory that includes a logs section and the appropriate values.

  4. You may have some .yaml parsing errors in your configuration files. Yaml is notoriously finicky, so when in doubt, a good yaml validator is worth referencing.

  5. Check if you have logs_enabled: true in your datadog.yaml

Check for errors in the logs

There might be an error in the logs that would explain the issue. So just run the following command and check for errors:

sudo cat /var/log/datadog/agent.log | grep logs

Docker environment

Log collection is not enabled

  1. Make sure the Datadog Agent has access to the Docker socket
  2. Check if the Agent user is in the Docker group: usermod -a -G docker dd-agent
  3. Check if log collection has been enabled DD_LOGS_ENABLED=true

Configuration issues

At least one valid log configuration must be set to start log collection. There are several options to configure log collection; ensure that at least one of them is activated:

  1. DD_LOGS_CONFIG_CONTAINER_COLLECT_ALL=true, which collects logs from all containers (see here how to exclude a subset)

  2. Autodiscovery via container labels. In this case, ensure that datadog.yaml has Docker listener and config provider:

  - name: docker
  - name: docker
    polling: true
  1. Autodiscovery in Kubernetes via pod annotations. In this case, ensure that datadog.yaml has the kubelet listener and config provider:
  - name: kubelet
  - name: kubelet
    polling: true

Further Reading