Searching for Logs

After configuring log structuring parsing and indexing, you can enter statements to search for log events that contain specific keywords. You can also search for log data by time range to locate events and issues that occur in a specified period.

Search statements are used to define the filter criteria for log query and obtain the logs that meet the criteria. A search statement may be a keyword, a value, a value range, a space, an asterisk (*), or the like. If it is a space or asterisk (*), no filtering criteria is specified. For more information, see Using Search Syntax.

Searching for Logs

Log in to the LTS console.
On the Log Management page, click the target log group or stream to access the log details page.
On the Log Search tab page, select a time range from the drop-down list to view log data accordingly.

Figure 1 Time range

There are three types of time range: relative time from now, relative time from last, and specified time. Select a time range as required.
- From now: queries log data generated in a time range that ends with the current time, such as the previous 1, 5, or 15 minutes. For example, if the current time is 19:20:31 and 1 hour is selected as the relative time from now, the charts on the dashboard display the log data that is generated from 18:20:31 to 19:20:31.
- From last: queries log data generated in a time range that ends with the current time, such as the previous 1 or 15 minutes. For example, if the current time is 19:20:31 and 1 hour is selected as the relative time from last, the charts on the dashboard display the log data that is generated from 18:00:00 to 19:00:00.
- Specified: queries log data that is generated in a specified time range. The time range can be up to three months for common users and six months for whitelisted users. If necessary, submit a service ticket to extend the time range to six months.
Enter search criteria in the search box based on Using Search Syntax to view, search for, and filter log data.

Figure 2 Log search
1. In the search area, click the search box, enter a keyword or select a field or keyword from the drop-down list, and click Search.
  - System reserved fields include appName, category, clusterId, clusterName, and collectTime. By default, the fields are displayed in simplified mode, and hostIP, hostName, and pathFile are displayed at the beginning. For more system reserved fields, see Configuring Log Indexing.
  - The structured fields are displayed in key:value format.
  - If there is too much content in the log search box, the content can be automatically wrapped and displayed in multiple lines. The height of the search box can be fixed.
2. In the search area, press the up and down arrows on the keyboard to select a keyword or search syntax from the drop-down list, press Tab or Enter to select a keyword or syntax, and click Search.
3. Click a field for which quick analysis has been enabled to add it to the search box. For details about how to enable quick analysis, see Creating a Quick Analysis Task.
  If the field you click already exists in the search box, it will be replaced by this newly added one. If the field is added for the first time, fields in the search box are searched using the AND operator.
On the Log Search tab page, perform the following operations. For more operations, see Common Log Search Operations.
1. Under Log Statistics, view the bar chart showing the log quantity in different time segments. The scale of the log quantity is displayed on the left.
  Figure 3 Log statistics
  
  If the embedding function is used, you can collapse or expand the log quantity statistics chart. For parameters of embedding LTS, see LTS URL.
2. In the log content area, hover the cursor over a field and click the log content in blue. You can search for logs by copying, adding to query, adding to query (interactive mode), creating query, excluding from query (interactive mode), hiding, and excluding from query.
3. In the log content area, you can select a list or raw log to display its log content.
  The log highlighting mechanism works as follows: Once a log meets the search criteria, the system identifies the log's strings that match these criteria and applies highlight tags to the matching sections, making them visibly highlighted on the page. However, when the query criteria are complex, particularly involving OR relationships, content that does not actually match the criteria may also be highlighted on the page.
When you search through a large amount of log data on the Log Search tab page, LTS automatically initiates an iterative search.
- During an iterative log search, you cannot enter any information in the search box. To pause the iterative search, click Pause. To resume the search, click Continue. You are advised not to initiate a new search task before the current iterative search is complete.
- For iterative searches that take a long time, you can narrow down the time range or add filters to reduce the number of iterative searches.
Set the layout of log data, including whether to display fields or display fields in a simple view.
1. Select Edit layouts from the layout drop-down list to access the layout setting page. The list also contains options such as the default layout, pure layout, and default container log layout, for you to set whether to display fields.
  Figure 4 Editing layouts
  - Cloud: This mode is applicable to users who have the write permission. Layout information is stored on the cloud.
  - Local Cache: This mode is applicable to users who have only the read permission. Layout information is cached in the local browser.
2. On the displayed Layout page, click + under Layout List to create a custom layout, name it, and configure how fields are displayed in this layout.
  Figure 5 Layout settings
3. After the setting is complete, click OK. The new custom layout is displayed in the drop-down list.
On the Log Search tab page, choose List. You can then set the columns to be displayed.
1. Hover the cursor over and click Set Columns. On the displayed page, set the columns to be displayed.
2. By default, the display of the time column and content column is enabled. All visible field names are listed under Displayed Columns. You can set aliases for fields. Properly configured aliases can make your logs easier to read and maintain, improving query efficiency. Click OK.
3. You can display or hide fields as described in Creating a Quick Analysis Task or 7.

Interactive Mode

Before using the interactive mode function, ensure that logs are properly reported and structured, and indexing have been configured. For details, see Using ICAgent to Collect Host Logs and Configuring Log Indexing.

If you have not configured ICAgent structuring parsing when configuring log ingestion to LTS, you can configure ICAgent or cloud configuring parsing for the target log stream separately. ICAgent structuring parsing is recommended. For details, see Configuring ICAgent Structuring Parsing.

The interactive search function generates simple search statements, allowing you to set search criteria and specify query filter rules on the LTS console to filter log records. For more functions or nested queries, enter SQL statements manually. For details, see Using SQL Analysis Syntax.

Click Interaction Mode in front of the search box to access the interactive search page.

Figure 6 Interactive Mode
Select the log search field and criteria from the drop-down list. The corresponding values of the field will be displayed in the search box. Add associations or groups to customize your search mode.
- The drop-down list displays index fields, structured fields, and system reserved fields.
- And indicates that all conditions must be met.
- Or indicates that only one of the conditions needs to be met.
For example, you can select fields such as content, collectTime, and category and set different conditions. Then you can preview the search statement at any time and modify the search criteria with ease.

(The following figure is for reference only.)
```
(content:"{\"write_traffic\":11,\"index_traffic\":133,\"storage\":17107}" AND collectTime=1728631667089) OR category:LTS
```
After setting the parameters, click OK. LTS searches for logs based on your search statement and displays the search results on the Log Search tab page. (The following figure is for reference only.)

Common Log Search Operations

In the log content display area, you can share and download logs, and view context. For details, see Table 1.

If your service network is unstable, the system is overloaded, or other unpredictable factors occur, a few logs may be duplicated or lost when they are reported to LTS.

**Table 1** Common operations
Operation	Description
Creating quick search	Click to create a quick search.
Viewing dashboards	Click to view the dashboards you created.
Adding alarm rules	Click and create an alarm rule on the displayed page.
Sharing logs	Click to copy the link of the current log search page to share the logs that you have searched.
Refreshing logs	You can click to refresh logs in two modes: manual refresh and automatic refresh. Manual refresh: Select Refresh Now from the drop-down list. Automatic refresh: Select an interval from the drop-down list to automatically refresh logs. The interval can be 15 seconds, 30 seconds, 1 minute, or 5 minutes.
Copying logs	Click to copy the log content.
Viewing context of a log	Click to view the log context. You can select Simple View to view the log context. You can also download the context.
More operations	Click to access the log details page of the time segment and view more log information. On the Extended Fields tab page, view field names and values. You can also click buttons in the Operation column to add a field to or exclude a field from a query, set whether a field exists or does not exist, or set whether a field is hidden. On the JSON Format tab page, view the JSON format of logs. On the Context Logs tab page, you can set the number of lines to be queried and filtered fields. You can also download logs and enable the summary mode.
Unfold/Fold	Click to display all the log content. This unfold button is enabled by default. Click to fold the log content.
Downloading logs	NOTE: This function is available only to whitelisted users. To enable it, submit a service ticket. Ensure that raw logs have been uploaded to the current log stream. Otherwise, an empty file will be downloaded. Click . On the displayed page, click Direct Download or Transfer and Download (this option is available only after one-off transfer is enabled). Direct Download: Download log files to the local PC. Up to 20 million logs can be downloaded at a time for a whitelisted user. A non-whitelisted user can download up to 5,000 logs at a time. Select .csv or .txt from the drop-down list and click Download to export logs to the local PC. Transfer and Download (available only to whitelisted users): Download log files through OBS transfer tasks. Up to 20 million logs can be downloaded at a time. Click Transfer to access the Configure Log Transfer page. For details, see Transferring Logs to OBS. Hover your cursor over and click View Download History. On the displayed page, copy log download links and view, download, and delete log download records.
Hiding/Expanding all	Click to set the number of lines displayed in the log content. Click to hide the log content.
JSON	Move the cursor over , click JSON, and set JSON formatting. Formatting is enabled by default. The default number of expanded levels is 2. If a log contains multiple backslashes, the first backslash will be lost when the log is displayed in JSON format because it will be processed as an escape character during JSON parsing. Formatting enabled: Set the default number of expanded levels. Maximum value: 10. Formatting disabled: JSON logs will not be formatted for display.
Collapse configuration	Move the cursor over , click Log Collapse, and set the maximum characters to display in a log. If the number of characters in a log exceeds the maximum, the extra characters will be hidden. Click Expand to view all. Logs are collapsed by default, with a default character limit of 400.
Log time display	Move the cursor over and click Log Time Display. On the page that is displayed, set whether to display milliseconds and whether to display the time zone. Milliseconds are displayed by default.
Virtual Scrolling	Move the cursor over and click Virtual Scrolling. On the page that is displayed, set whether to enable virtual scrolling and enter the buffer size. Virtual scrolling eliminates or minimizes frame and page freezing for better user experience. Data is re-rendered during the process. This may affect smoothness. The buffer size determines the amount of data that can be loaded simultaneously. The larger the buffer, the more data loaded simultaneously, but the worse the scrolling performance.
Invisible fields ()	This list displays the invisible fields configured in the layout settings. The button is unavailable for log streams without layout settings configured. If the log content is CONFIG_FILE and layout settings are not configured, the default invisible fields include appName, clusterId, clusterName, containerName, hostIPv6, NameSpace, podName, and serviceID.

Cross-Stream Search

On the log stream details page, you can search for logs across log streams. This meas you can search for logs in other log streams without exiting the current log search page.

On the log stream details page, click .
On the displayed page, select one or more target log streams.
Click OK.
On the target log stream details page displayed, search for logs by referring to Using Search Syntax.

To change the log stream, click next to Cross-Stream Search in the upper left corner and select another log stream.
After the search is complete, click Exit in the upper right corner to return to the current log stream search page.
- If the target log streams for cross-stream search use different delimiters, the log keywords in different streams will be highlighted differently.
- Up to 50 log streams can be searched at a time.
- Only raw logs can be searched. SQL statements cannot be used for statistical analysis.
- You can select log streams across log groups, but not across regions.
- If you select multiple log streams with different index configurations for cross-stream search, for example, indexing Key1 in stream A but not in stream B, searches for Key1:xxx will only return logs from stream A. Address the issue according to the error message and retry the log search.

Helpful Links

You can use the log alarm function of LTS to set alarm rules to notify you of exceptions in the ingested logs. For details, see Configuring Log Alarm Rules.
If you have any questions during log search, see Log Search and Analysis in the FAQ.
For best practices of log search and analysis, see Log Search and Analysis in the Best Practices.
1. You can analyze ingested WAF logs on the LTS console. For details, see Analyzing Huawei Cloud WAF Logs on LTS.
2. You can embed the log query page of LTS into your system. For details, see Embedding the LTS Log Query Page into a User-built System.