Slow query log

Video introduction

Procedure

1. Log on to the DAS console.

2. In the navigation pane on the left, click Intelligent O&M Center > Instance Monitoring .

3. Find the target instance and click the instance ID to open the instance details page.

4. In the left-side navigation pane, click Request Analysis > Slow Logs.

5. Select a time range to view the Slow Log Trend, Event Distribution, Slow Log Statistics, and Slow Log Details.

   Note

   The end time must be later than the start time, and the time range cannot exceed seven days. You can query slow query logs from the last month.

   • In the Slow Log Trend chart, you can select a specific point in time to view the corresponding Slow Log Statistics and Slow Log Details.

     Note

     If a slow SQL statement is too long to be fully displayed, hover the pointer over the statement to view the complete text in a pop-up window.

   • For sharded cluster instances, use the Node ID drop-down list to view the number of slow queries for each node.

   • On the Slow Query Log Statistics and Slow Query Log Details tabs, click to save the slow query log information to a local file.

   • Click to go to OpenAPI Explorer and debug the API. The currently selected and entered parameters are passed automatically.

   • In the Event Distribution section, you can find slow log events within the specified time range. Click an event to view its details.

   • In the Slow Log Statistics section, click Details in the Actions column of a log template to view its Slow Log Sample .

   • In the Slow Log Statistics section, click Optimize in the Actions column of a log template to view the diagnostic results in the Optimize dialog box.

     Note

     The optimization feature is available only for slow queries where the Operation Type is query. It primarily provides index optimization suggestions.

     Supported scenarios

     • Single-field query: For example, if DAS flags a db.col.find({ a: 1 }) query as slow, it recommends creating the corresponding index: db.col.createIndex({ a: 1 }).

     • Multi-field query: For example, if DAS flags a db.col.find({ a: 1, b: 1 }) query as slow, it recommends creating a compound index: db.col.createIndex({ a: 1, b: 1 }).

     Unsupported scenarios

     • DAS does not recommend indexes that already exist.

     • Special index types, such as text, unique, and hash, are not supported.

     • Queries that contain complex logical operators, such as $or and $and, are not supported.

     • DAS cannot generate index suggestions for operations other than find, such as sorting ($sort) and collation ($collation).

     If you accept the suggestion, click Copy in the upper-right corner, then paste and run the statement in a database client or DMS. To reject the suggestion, click Cancel.

     Important

     Adding an index might degrade the execution plans of other queries and consume instance resources such as storage. Before you apply a suggestion, you must assess the potential risks, including the impact on related queries and resource consumption.

FAQ