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, contact Datadog support for further assistance.

Restart the Agent

Changes in the configuration of the datadog-agent won’t be taken into account until you have restarted the 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 intake.logs.datadoghq.com:10516
  • telnet intake.logs.datadoghq.com 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 configure the Datadog Agent to send logs through HTTPS by adding the following in datadog.yaml:
  force_use_http: true

See the HTTPS log forwarding section for more information.

Check the status of the Agent

Often, checking the Agent status command results will help you troubleshoot what is happening.

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 tailing log files

The datadog-agent does not run as root (and running as root is not recommended, 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.

In that case, you should see an error message when checking the Agent status:

Logs Agent

    Type: file
    Path: /var/log/application/error.log
    Status: Error: file /var/log/application/error.log does not exist

Run the namei command to obtain more information about the file permissions:

> namei -m /var/log/application/error.log
> f: /var/log/application/error.log
 drwxr-xr-x /
 drwxr-xr-x var
 drwxrwxr-x log
 drw-r--r-- application
 -rw-r----- error.log

In this example, the application directory is not executable by the Agent, therefore the Agent cannot list its files. Furthermore, the Agent does not have read permissions on the error.log file. Add the missing permissions via the chmod command.

Permission OK

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.

Permission issue and Journald

When collecting logs from Journald, make sure that the Datadog Agent user is added in the systemd group as shown in the Journald integration.

Note: Journald sends an empty payload if the file permissions are incorrect. Accordingly, it is not possible to raise or send an explicit error message in this case.

Configuration issues

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

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

  2. Check if you have logs_enabled: true in your 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 can be finicky, so when in doubt rely on a YAML validator.

Check for errors in the Agent logs

There might be an error in the logs that would explain the issue. Run the following command to check for errors:

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

Docker environment

See the Docker Log Collection Troubleshooting Guide

Serverless environment

See the Lambda Log Collection Troubleshooting Guide

Unexpectedly dropping logs

Check if logs appear in the Datadog Live Tail. If they appear in the Live Tail, check the Indexes configuration page for any exclusion filters that could match your logs.

Further Reading