This topic describes performance metrics that are supported by the performance trend feature of DAS and how to view these performance metrics.

Prerequisites

A database instance is connected to DAS and the database instance is in the Accessed state. The anomaly detection feature is available only for ApsaraDB RDS for MySQL. For information about how to connect a database instance to DAS, see the following topics:

Background information

The performance trend feature supports metrics such as the TPS, QPS, and throughput. You can view performance trends in multiple ways. For example, you can compare performance trends and view custom performance trend charts.

Performance metrics

You can view the following metrics for performance trends. A MySQL database instance is used in this example.

Note You can view the description of each metric by clicking Definition? in the upper-right corner of each metric section.
Metric Unit Description
mysql.tps Per Second The number of transactions per second.
mysql.qps Per Second The number of requests per second.
mysql.total_session Count The number of total sessions.
mysql.active_session Count The number of active sessions.
mysql.bytes_received KByte The average number of bytes received from all clients per second.
mysql.bytes_sent KByte The average number of bytes sent to all clients per second.
mysql.tb.tmp.disk Count The number of temporary tables that are automatically created on disks when MySQL executes statements.
mysql.insert_ps Per Second The average number of INSERT statements executed per second.
mysql.select_ps Per Second The average number of SELECT statements executed per second.
mysql.update_ps Per Second The average number of UPDATE statements executed per second.
mysql.delete_ps Per Second The average number of DELETE statements executed per second.
mysql.replace_ps Per Second The average number of REPLACE statements executed per second.
mysql.innodb_data_written KByte The average number of bytes that InnoDB writes per second.
mysql.innodb_data_read KByte The average number of bytes that InnoDB reads per second.
mysql.innodb_buffer_pool_reads_requests Count The average number of logical page reads from the InnoDB buffer pool per second.
mysql.innodb_bp_dirty_pct % The dirty page ratio of the InnoDB buffer pool. Calculation formula: Innodb_buffer_pool_pages_dirty/Innodb_buffer_pool_pages_data × 100%.
mysql.innodb_bp_hit % The read hit rate of the InnoDB buffer pool. Calculation formula: (Innodb_buffer_pool_read_requests - Innodb_buffer_pool_reads)/Innodb_buffer_pool_read_requests × 100%.
mysql.innodb_bp_usage_pct % The usage of the InnoDB buffer pool. Calculation formula: Innodb_buffer_pool_pages_data/(Innodb_buffer_pool_pages_data + innodb_buffer_pool_pages_free) × 100%.
mysql.innodb_log_writes Per Second The average number of physical writes to the InnoDB redo log file per second.
mysql.innodb_os_log_fsyncs Per Second The average number of fsync() writes to the log file per second.
mysql.innodb_rows_deleted Per Second The average number of rows deleted from InnoDB tables per second.
mysql.innodb_rows_read Per Second The average number of rows read from InnoDB tables per second.
mysql.innodb_rows_inserted Per Second The average number of rows inserted into InnoDB tables per second.
mysql.innodb_log_writes Per Second The average number of physical writes to the InnoDB redo log file per second.
mysql.innodb_rows_updated Per Second The average number of rows updated in InnoDB tables per second.
mysql.mem_usage % The memory usage of the MySQL instance within the entire operating system.
mysql.cpu_usage % The CPU utilization of MySQL processes. This metric can reach up to 100% for Alibaba Cloud database instances.
mysql.data.size MByte The data size.
mysql.tmp.size MByte The temporary tablespace.
mysql.other.size MByte The system space.
mysql.instance.size MByte The total space usage of the MySQL database instance.
mysql.log.size MByte The log size.
mysql.iops Count The IOPS of the MySQL database instance.

Procedure

You can perform the following steps to view the performance trend within a specified time range.

  1. Log on to the DAS console.
  2. In the left-side navigation pane, click Instance Monitoring.
  3. On the Instance Monitoring page, find the instance that you want to view and choose Performance > Performance Trend in the Actions column.
    Note You can specify a time range, select metrics from the More Metrics drop-down list based on your needs, and then click Search.
  4. Click the Performance Trend Comparison tab. Specify two time ranges and click Search.
    Note You can customize multiple performance monitoring dashboards and customize multiple performance metrics in the same chart for troubleshooting and analysis.
  5. Click the Custom Chart tab.
    Note If you use the custom chart feature for the first time, you must create a monitoring dashboard. For more information, see Monitoring dashboard. You can specify a time range based on your needs, and click Search to view custom charts.