The Storage Monitoring page shows real-time performance data for the storage nodes in a PolarDB-X 1.0 instance. Use it to spot resource bottlenecks, track engine activity, and decide when to scale or tune your database.
Monitoring metrics
Storage node metrics are grouped into two categories:
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Resource — infrastructure-level metrics (CPU, memory, disk, connections, network). Collected every 1 minute.
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Engine — InnoDB and query-level metrics. Collected every 5 seconds.
You can query monitoring data for up to seven days.
Key metrics to watch
Before scanning all 15 metrics, focus on these first — they surface the most common bottlenecks:
| Metric | Why it matters |
|---|---|
| CPU and memory | Sustained high CPU or memory usage signals that the instance is under-provisioned or running expensive queries. |
| IOPS | A spike approaching the instance's IOPS limit causes query latency to rise across the board. |
| Connections | A sharp rise in active connections combined with slower response times indicates connection exhaustion. |
| InnoDB cache | A low read hit ratio means InnoDB is reading from disk instead of the buffer pool. Increase the buffer pool size or optimize queries to improve it. |
| TPS/QPS | A sudden drop in TPS or QPS without a corresponding drop in connections often signals lock contention or a long-running transaction. |
Resource metrics
| Metric | Parameter | Description | Unit |
|---|---|---|---|
| CPU and memory | MySQL_MemCpuUsage |
CPU utilization and memory usage of the storage node | % |
| Disk size | MySQL_DetailedSpaceUsage |
Usage of total space, data space, log space, temporary space, and system space | MB |
| IOPS | MySQL_IOPS |
Input/output operations per second (IOPS) of the storage node | ops/s |
| Connections | MySQL_Sessions |
Number of active connections and total connections | count |
| Network traffic | MySQL_NetworkTraffic |
Inbound and outbound traffic per second | KB/s |
Engine metrics
| Metric | Parameter | Description | Unit |
|---|---|---|---|
| TPS/QPS | MySQL_QPSTPS |
Average SQL statements executed per second (QPS) and average transactions per second (TPS) | count/s |
| InnoDB cache | MySQL_InnoDBBufferRatio |
Read hit ratio, usage, and dirty ratio of the InnoDB buffer pool | % |
| InnoDB read/write | MySQL_InnoDBDataReadWriten |
Average data read and written by InnoDB per second | KB/s |
| Cached requests | MySQL_InnoDBLogRequests |
Average reads from and writes to the InnoDB buffer pool per second | count/s |
| InnoDB log | MySQL_InnoDBLogWrites |
Average log write requests per second, physical writes to log files per second, and fsync operations per second | count/s |
| Temporary tables | MySQL_TempDiskTableCreates |
Temporary tables automatically created on disk during statement execution | count |
| COMDML | MySQL_COMDML |
Average executions per second for DELETE, INSERT, INSERT_SELECT, REPLACE, REPLACE_SELECT, SELECT, and UPDATE statements | count/s |
| RowDML | MySQL_RowDML |
Average rows read, updated, deleted, and inserted in InnoDB tables per second, plus physical writes to log files per second | count/s |
| MyISAM read/write | MySQL_MyISAMKeyReadWrites |
Average reads and writes to the MyISAM buffer pool per second, and reads and writes to disk per second | count/s |
| MyISAM key | MySQL_MyISAMKeyBufferRatio |
Average usage, read hit ratio, and write hit ratio of the MyISAM key buffer per second | % |
View storage node monitoring data
Prerequisites
Before you begin, ensure that you have:
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A PolarDB-X 1.0 instance in your account
Steps
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Log on to the PolarDB for Xscale console.
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In the top navigation bar, select the region where the instance is located.
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On the Instances page, find the instance and click the instance ID.
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In the left-side navigation pane, choose Monitoring and Alerting > Storage Monitoring.
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On the Storage Monitoring page, set the following parameters.
Parameter Description Database The database whose metrics you want to view. Select a database from the Database drop-down list. Monitoring Index First, select a category: Resource or Engine. Then select the specific monitoring metric to display. Query Time The time range for the query. Select 1 hour, 6 hours, 12 hours, one day, or one week. To set a custom range, specify start and end times — the minimum range is 1 minute and the maximum is one week.
What's next
To get notified when a metric crosses a threshold, set up an alert rule. See Configure alert rules.