Logging is here!

Live Tail

Live tail

Overview

The Live Tail feature gives you the ability to see all your log events in near real time from anywhere in your infrastructure. It displays logs as soon as they get out of the Pipeline section and before their indexation by Datadog, hence:

  1. All logs ingested by Datadog are displayed. (It’s logging without limits.)
  2. Displayed logs have been processed.
  3. The stream can be paused.
  4. You can’t go back in the past.

This feature allows you, for instance, to check if a process has correctly started, or if a new deployment went smoothly.

Live Tail view

Choose the Live Tail option in the time range selector to switch to the Live Tail view:

Live Tail time selector

The number of received events per second is displayed at the top left, as well as the sampling rate. Since a stream of thousands of logs per second is not human readable, high throughput log streams are sampled.

Use the Live Tail search bar filtering features to filter the log stream and the Pause/Play button at the top right of the screen to pause or resume the stream.

Note: Selecting any log pauses the stream and displays more details about the selected log.

Display Options

Customize the Live Tail view to better highlight the relevant information in your logs. Click on the gear at the top right of the page to activate one of the options below:

Live tail column
  1. Choose to display one, three, or ten lines from your logs attributes in your logstream.
  2. Enable/Disable the Date and Message column.
  3. Add any log attribute as a column either in this panel or by clicking on it directly:
Live tail add as column

Filtering the log Stream

A valid query into the search bar displays logs that match your search criteria. The search syntax is the same in the Live Tail views as in the other Log views, but here, your query is matched against all of the ingested logs and not just the indexed ones.

JSON attributes

Any query that works in other views works in the Live Tail view, but you can even go further and filter on attributes that are not defined as facets.

For example, to filter on the following filename attribute there are two options:

Live tail save
  1. Click on the attribute and add it to the search:

    Live tail click attribute
  2. Use the following query @filename:runner.go:

    Live tail filtered

To filter on all logs with a line number above 150 use the following query: @linenumber:>150

Further Reading