Viewing and Downloading Slow Query Logs

Scenarios

Slow query logs record statements that exceed long_query_time (1 second by default). You can view log details and statistics to identify statements that are executing slowly and optimize the statements. You can also download slow query logs for service analysis.

Viewing Log Details

1. Log in to the management console.
2. Click in the upper left corner and select a region and a project.
3. Click Service List. Under Database, click Relational Database Service. The RDS console is displayed.
4. On the Instance Management page, click the target DB instance.
5. In the navigation pane on the left, choose Logs. On the Slow Query Logs page, click Log Details to view details about slow query logs.
   • You can view the slow query log records of a specified execution statement type or a specific time period.
   • The long_query_time parameter determines when a slow query log is recorded. However, changes to this parameter do not affect already recorded logs. If long_query_time is changed from 1s to 0.1s, none of the previously recorded logs that do not meet the new threshold are deleted. For example, a 1.5s SQL statement that was recorded when the threshold was 1s will not be deleted now that the new threshold is 2s.

Viewing Statistics

1. Log in to the management console.
2. Click in the upper left corner and select a region and a project.
3. Click Service List. Under Database, click Relational Database Service. The RDS console is displayed.
4. On the Instance Management page, click the target DB instance.
5. In the navigation pane on the left, choose Logs. On the Slow Query Logs page, click Statistics to view details.
   

   • On the Statistics page, only one of the SQL statements of the same type is displayed as an example. For example, if two select sleep(N) statements, select sleep(1) and select sleep(2), are executed in sequence, only select sleep(1) will be displayed.
   • The long_query_time parameter determines when a slow query log is recorded. However, changes to this parameter do not affect already recorded logs. If long_query_time is changed from 1s to 0.1s, none of the previously recorded logs that do not meet the new threshold are deleted. For example, a 1.5s SQL statement that was recorded when the threshold was 1s will not be deleted now that the new threshold is 2s.

Downloading a Slow Query Log

1. Log in to the management console.
2. Click in the upper left corner and select a region and a project.
3. Click Service List. Under Database, click Relational Database Service. The RDS console is displayed.
4. On the Instance Management page, click the target DB instance.
5. In the navigation pane on the left, choose Logs. On the Slow Query Logs page, click Download. In the log list, locate a log whose status is Preparation completed and click Download in the Operation column.
   • The system automatically loads the downloading preparation tasks. The loading duration is determined by the log file size and network environment.
     • When the log is being prepared for download, the log status is Preparing.
     • When the log is ready for download, the log status is Preparation completed.
     • If the preparation for download fails, the log status is Abnormal.

     Logs in the Preparing or Abnormal status cannot be downloaded.

   • The download link is valid for 5 minutes. After the download link expires, a message is displayed indicating that the download link has expired. If you need to download the log, click OK.