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Exception detection

Last Updated: Jun 02, 2020

DAS uses machine learning and intelligent algorithms to monitor and predict core metrics of database instances. DAS can also help find root causes by associating the one-click diagnosis module.


DAS has accessed the database instance and the access status is Accessed. The exception detection feature is only available to MySQL databases.

For more information about how to access a database instance, see

Monitoring metrics

The Exception Detection tab of DAS displays the following metrics.

Metric Description
tps Formula: (Com_commit + Com_rollback)/Uptime
qps Formula: Questions/Uptime
active_session Active sessions
delete_ps The average number of DELETE statements executed per second
insert_ps The average number of INSERT statements executed per second
update_ps The average number of UPDATE statements executed per second
select_ps The average number of SELECT statements executed per second
bytes_received The average number of bytes received from all clients per second
bytes_sent The average number of bytes sent to all clients per second
innodb_bp_hit The read hit rate of InnoDB buffer pool. Formula: (Innodb_buffer_pool_read_requests - Innodb_buffer_pool_reads)/Innodb_buffer_pool_read_requests × 100%
innodb_data_written The average number of bytes written by InnoDB per second
innodb_data_read The average number of bytes read by InnoDB per second
mysql.innodb_log_writes The average number of redo log file physical writes to InnoDB per second
innodb_rows_deleted The average number of rows deleted by InnoDB per second
innodb_rows_read The average number of rows read by InnoDB per second
innodb_rows_inserted The average number of rows inserted by InnoDB per second
innodb_rows_updated The average number of rows updated by InnoDB per second
mysql.mem_usage The CPU utilization of the MySQL instance within the entire operating system.
mysql.cpu_usage The CPU utilization of MySQL processes (up to 100% of Alibaba Cloud databases)


  1. Log on to the DAS console.

  2. In the left-side navigation pane, click Instance Monitoring.

  3. On the Instance Monitoring page, select a database engine tab.

  4. Find the target instance. Choose Performance > Performance Trend in the Actions column.Console

  5. Click the Exception Detection tab.

    You can view error information on this tab.