PolarDB for MySQL provides advanced monitoring features. Advanced monitoring supports a wide range of performance metrics, custom charts, and powerful diagnostic capabilities. It can detect events that occur on your database cluster in real time, perform automatic diagnosis, and generate root cause analysis and recommendations. You can also select a specific time range to trigger on-demand diagnosis and understand the running status of your database cluster.
Procedure
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Log on to the PolarDB console. In the left-side navigation pane, click Clusters, select the region where the cluster is deployed, and then click the ID of the target cluster to go to the cluster details page.
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In the left-side navigation pane, choose , and then click the Advanced Monitoring tab.
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On the Advanced Monitoring page, select a node to view its performance trend charts for the last 1 hour, last 1 day, or last 7 days.
NoteYou can also click Monitoring Dashboard to monitor the health status of all database instances under your account in the DAS console.
Performance metrics
Advanced monitoring supports the following performance metrics.
You can click 
next to a metric to view its description.
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Category |
Metric |
Description |
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Basic Metrics |
CPU Usage |
mem_usage |
The memory usage of the cluster as a percentage of the total operating system memory. Unit: percentage. |
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Memory Utilization |
cpu_usage |
The CPU utilization of the service process. A value of 200% indicates that 2 CPU cores are used. Unit: percentage. |
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Network Traffic |
input_traffic |
The average number of bytes received from all clients per second. Unit: KB. |
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output_traffic |
The average number of bytes sent to all clients per second. Unit: KB. |
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IOPS Usage |
iops_usage |
The IOPS usage. Unit: percentage. |
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Storage Space Usage |
binlog_size |
The storage space occupied by binary logs. Unit: MB. |
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data_size |
The storage space occupied by data. Unit: MB. |
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compressed_data_size |
The storage space occupied by compressed tables. Unit: MB. |
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log_size |
The storage space occupied by logs. Unit: MB. |
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other_log_size |
The size of other logs. Unit: MB. |
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redolog_size |
The storage space occupied by redo logs. Unit: MB. |
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sys_dir_size |
The storage space occupied by the system. Unit: MB. |
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tmp_dir_size |
The storage space occupied by temporary files. Unit: MB. |
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undolog_size |
The storage space used by undo logs. Unit: MB. |
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IOPS |
iops |
The total IOPS. Unit: counts/s. |
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iops_r |
The read IOPS. Unit: counts/s. |
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io_throughput |
The total I/O throughput. Unit: MB. |
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io_throughput_r |
The read I/O throughput. Unit: MB. |
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io_throughput_w |
The write I/O throughput. Unit: MB. |
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iops_w |
The write IOPS. Unit: counts/s. |
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Database Metrics |
QPS/TPS |
qps |
The number of queries per second. Formula: Queries / Uptime. Unit: queries/s. |
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tps |
The number of transactions per second. Formula: (Com_commit + Com_rollback) / Uptime. Unit: transactions/s. |
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mps |
The number of operations per second. Unit: operations/s. |
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Session Connection |
active_session |
The number of active sessions. Unit: count. |
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total_session |
The total number of sessions. Unit: count. |
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Number of executions |
com_select |
The average number of SELECT statements executed per second. Unit: statements/s. |
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com_insert |
The average number of INSERT statements executed per second. Unit: statements/s. |
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com_update |
The average number of UPDATE statements executed per second. Unit: statements/s. |
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com_delete |
The average number of DELETE statements executed per second. Unit: statements/s. |
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com_replace |
The average number of REPLACE statements executed per second. Unit: statements/s. |
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com_insert_select |
The average number of INSERT_SELECT statements executed per second. Unit: statements/s. |
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com_replace_select |
The average number of REPLACE_SELECT statements executed per second. Unit: statements/s. |
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com_delete_multi |
The average number of Multi-DELETE statements executed per second. Unit: statements/s. |
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com_update_multi |
The average number of Multi-UPDATE statements executed per second. Unit: statements/s. |
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Temporary table |
created_tmp_disk_tables |
The number of temporary tables created per second. Unit: tables/s. |
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Number of Blocking Connections |
mdl_lock_session |
The number of connections blocked by MDL locks. Unit: count. |
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other_lock_session |
The number of connections blocked by other locks. Unit: count. |
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Thread Pool |
thread_pool_running_threads |
The number of running threads in the thread pool. Unit: count. |
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tp_high_queue_count |
The number of requests in the high-priority queue of the thread pool. Unit: count. |
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tp_low_queue_count |
The number of requests in the low-priority queue of the thread pool. Unit: count. |
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tp_thread_count |
The total number of threads in the thread pool. Unit: count. |
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Innodb history transaction list length |
Innodb_trx_history_list_len |
The length of the historical transaction list. Unit: count. |
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Com_stmt status |
Com_stmt_close |
The cumulative number of Com_stmt_close executions. Unit: executions/s. |
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Com_stmt_execute |
The cumulative number of Com_stmt_execute executions. Unit: executions/s. |
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Com_stmt_fetch |
The cumulative number of Com_stmt_fetch executions. Unit: executions/s. |
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Com_stmt_prepare |
The cumulative number of Com_stmt_prepare executions. Unit: executions/s. |
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Com_stmt_reprepare |
The cumulative number of Com_stmt_reprepare executions. Unit: executions/s. |
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Com_stmt_reset |
The cumulative number of Com_stmt_reset executions. Unit: executions/s. |
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Com_stmt_send_long_data |
The cumulative number of Com_stmt_send_long_data executions. Unit: executions/s. |
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Prepared_stmt_count |
The current number of prepared statements. Unit: count. |
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InnoDB storage engine |
InnoDB Row Operations |
innodb_rows_deleted |
The average number of rows deleted from InnoDB tables per second. Unit: rows. |
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innodb_rows_inserted |
The average number of rows inserted into InnoDB tables per second. Unit: rows. |
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innodb_rows_read |
The average number of rows read from InnoDB tables per second. Unit: rows. |
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innodb_rows_updated |
The average number of rows updated in InnoDB tables per second. Unit: rows. |
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InnoDB line lock |
innodb_row_lock_current_waits |
The current number of row lock waits on InnoDB tables. Unit: waits/s. |
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innodb_row_lock_time |
The total lock time since the system started. Unit: milliseconds. |
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innodb_row_lock_time_avg |
The average row lock wait time on InnoDB tables. Unit: milliseconds. |
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innodb_row_lock_time_ps |
The row lock wait time per second on InnoDB tables. Unit: milliseconds. |
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innodb_row_lock_waits |
The number of row lock waits per second on InnoDB tables. Unit: waits/s. |
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innodb_row_lock_waits_ps |
The number of row lock waits per second on InnoDB tables. Unit: waits/s. |
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InnoDB Buffer Pool hit rate |
innodb_buffer_dirty_ratio |
The ratio of dirty pages in the InnoDB buffer pool. Formula: Innodb_buffer_pool_pages_dirty / Innodb_buffer_pool_pages_data × 100%. Unit: percentage. |
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innodb_buffer_read_hit |
The read cache hit ratio of the InnoDB buffer pool. Formula: (Innodb_buffer_pool_read_requests - Innodb_buffer_pool_reads) / Innodb_buffer_pool_read_requests × 100%. Unit: percentage. |
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innodb_buffer_use_ratio |
The InnoDB buffer pool usage. Formula: innodb_buffer_pool_pages_data / (innodb_buffer_pool_pages_data + innodb_buffer_pool_pages_free) × 100%. Unit: percentage. |
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InnoDB Buffer Pool requests |
innodb_buffer_pool_read_requests |
The number of buffer pool read requests per second. Unit: requests/s. |
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innodb_buffer_pool_write_requests |
The number of buffer pool write requests per second. Unit: requests/s. |
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Innodb history transaction list length |
Innodb_trx_history_list_len |
The length of the historical transaction list. Unit: count. |
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InnoDB Data read and write throughput |
innodb_data_read |
The average number of bytes read from InnoDB per second. Unit: B. |
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innodb_data_written |
The average number of bytes written to InnoDB per second. Unit: B. |
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InnoDB Redo writes per second |
Innodb_os_log_written |
The average amount of redo log data written to InnoDB per second. Unit: B. |
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InnoDB Redo write times |
innodb_log_write_requests |
The number of physical log writes per second. Unit: writes/s. |
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innodb_os_log_fsyncs |
The number of fsync operations per second. Unit: operations/s. |
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Replication |
Replication Latency |
Replica_lag_ms |
The replication latency. Unit: milliseconds. |