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Slow Query

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It reads the slow query logs from the database and display them as a visual chart. The reference time for a slow query is set in a DB parameter, and the SQL in the slow query log is displayed.

Info

Even for the same SQL, in case of the SQL Elapse Map metric in Monitoring Multiple Instances, an error may occur because the time is calculated based on active sessions.

Guide on how to use​

To use the Slow Query menu, set parameters and roles as follows.

Configuration of the DBX agent file​

whatap.conf
slow_query_log=ON

Configuring the DB parameters and roles​

my.cnf
slow_query_log = 1
long_query_time = 3 # e.g. Recording for SQLs taking 3 seconds or more
log_output=FILE # or TABLE
Note

  • If you set the log_output=FILE option on the DB server, xos installation is required. For more information, see the following.

  • If you are using AWS RDS and set the log_output=FILE option, configure the settings to use CloudWatch instead of xos installation. For more information, see the following.

  • If you use other clouds, set the log_output=TABLE option to use the Slow query menu. However, in the environments where many slow queries occur, caution is required because the DB performance may decrease when viewing mysql.slow_log.

  • If you set the log_output=TABLE option, assign the lookup role to the monitoring account. Execute the following command.

    grant select on mysql.slow_log to whatap;

XOS agent configuration of the DB server​

Set as follows to adjust the collection cycle for slow queries.

xos.conf
slow_query_interval = 30 # Default 30 seconds
Note

To monitor slow queries, be sure to install the XOS agent on the DB server. For more information about the XOS agent installation, see the following.

Basic screen guide​

slow query

  • Leader line 1 Time / Instance

    You can change the duration of an active session or select individual instances.

  • Leader line 2 Slow Query

    It displays the times of slow queries with a chart. If you drag a specific area with you mouse, you can see information details in Leader line 3 Slow Query List.

  • Leader line 3 Slow Query List

    The slow query details on the area dragged on the Slow Query chart are displayed in the list. If SQL is selected, you can see the (query)'s full text and plan information.

See query details​

To check the SQL query information of the current running session, select the SQL column in the Slow Query List section. The SQL details window appears. You can check the SQL query statements and plan information.

SQL details

  • View SQL Statistics: You can go to the SQL statistics menu where you can check statistical information related to the SQL query statement.

  • Default Bind: You can bind the part set as a variable in the query sentence to the default value.

  • Reset Bind: You can release the bound default value and check the variable.

  • Formatting: You can improve readability by applying indentation and formatting to a SQL query statement.

  • Plan: To check plan information, enter DB Name, User Name, and Password, and then select Search icon.

    • Text: You can check plan information in text format.

    • JSON: By viewing the plan information in Json format, you can quickly find the points where bottlenecks occur.

    Note

    The function to view plan information in JSON format is supported only in DBX agent 1.6.15 or later.

Tip

If you select a table or index while viewing the plan information in JSON format, the Object detail window appears where you can see the configurations for columns and index items in the table.

Object detail

This function is supported in DBX agent 1.6.15 or later. For more information about the database roles and related settings, see the following.