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Torch Log Service

Query and analysis

Scroll logs in real time using LiveTail

The LiveTail feature in TLS is mainly used for online operations and maintenance scenarios. It supports real-time log streaming and highlighting key information. With this feature, operation and maintenance staff can quickly identify exceptions and improve efficiency. This topic introduces the basic features and operations of the LiveTail feature.

Prerequisites

Logs have been collected.

LiveTail is only supported for logs collected by LogCollector 1.0.6 and later versions. Log data uploaded through other methods, such as the PutLogs API via SDK, does not support context queries. For detailed steps, see Single-line full text mode,Write logs using the Go SDK.

Indexing has been configured for the logs. For detailed steps, see Configuration Index.

Background information

In operations scenarios, monitoring log queues in real time and extracting key information for quick analysis of exception causes are crucial tasks. Traditional operations typically require running the tail -f command on the server to monitor log files in real time. To further filter information, you also need to use the grep or grep -v commands for keyword filtering. To some extent, these operations are complex and inefficient. However, the LiveTail feature provided by TLS is meant to simplify this process. The main features of LiveTail include:

Supports real-time log capture and display of the latest log file content, helping you quickly identify exceptions.

Supports setting keywords to filter logs and displays only the logs you need.

Supports tracking and monitoring corresponding log files based on individual logs, without logging in to the server.

Limits

The LiveTail log list displays up to 1000 logs within the scrollable range. When the 1000 log limit is reached, the system automatically refreshes the list and fills in new logs.

Steps

Select the region where log service is located from the top navigation bar.

In the left navigation pane, select Common functions > Query and analysis, and click the project name.

On theQuery and analysis page, in the left list, and then select the target project and log topic.

On the query and analysis page for the specified log topic, enter the query statement and set the time range.

On the Raw log tab, locate the specified log and click the LiveTail icon.

In the LiveTail panel, review the results.

Once LiveTail is enabled, the system automatically identifies logs from the same file as the specified log and displays them in real time as a log stream in the log list. Each newly written log is promptly added to the bottom of the list. Besides, the scroll bar stays at the bottom by default. You can keep up with log updates quickly.

You can also perform the following actions.

Highlight: In the Highlight text box, enter a word or string to highlight it in the logs.

Filter string: In the Filter string text box, enter a word or string to display only logs containing that string in the list.

Stop LiveTail: If you do not need LiveTail, click the pause button to stop log analysis.

Last updated: 2026.01.05 18:43:06