CloudMonitor provides an overview of alerts, key events, and resource usage.
On the Overview page, you can check the resource usage and alerts of each Alibaba
Cloud service in real time. The following figure shows the Overview page. 
Alert overview
In the Alert Overview section, CloudMonitor provides alert statistics, including the
total number of alerts in the latest seven days, the number of triggered alert rules,
the number of alert rules with insufficient data, and the usage of text messages in
the current month.
- You can click Total Alarms in 7 Days to view the alert trend chart and alert history in the latest seven days.
- You can click Alerts to view the details of triggered alert rules.
- You can click Insufficient Data to view the details of alert rules with insufficient data.
Event overview
In the Event Overview section, CloudMonitor summarizes all the exceptions and O&M events that occurred within the latest 24 hours. The following table lists the key events that are supported.
| Cloud service | Event name |
|---|---|
| Hosts | Agent Stopped |
| ApsaraDB RDS | Master/Slave Instance Switch |
| ApsaraDB RDS | Instance Faults |
| ApsaraDB for MongoDB | Instance Faults |
| ApsaraDB for Redis | Master/Slave Instance Switch |
| ApsaraDB for Redis | Instance Faults |
Resource usage
In the Resource Usage section, CloudMonitor displays the overall resource usage of each Alibaba Cloud service within your account. CloudMonitor uses the 95th percentile to measure the resource usage of most Alibaba Cloud services.
The following table describes the statistical metrics of Alibaba Cloud services.
| Service | Metric name | Statistical method | Statistical period | Statistical range |
|---|---|---|---|---|
| Hosts | CPU utilization | 95th percentile | Real-time | All instances |
| Hosts | Memory usage | 95th percentile | Real-time | All instances |
| Hosts | Disk usage | 95th percentile | Real-time | All instances |
| Hosts | Outbound bandwidth over the Internet | 95th percentile | Real-time | All instances |
| ApsaraDB RDS | CPU utilization | 95th percentile | Real-time | All instances |
| ApsaraDB RDS | IOPS usage | 95th percentile | Real-time | All instances |
| ApsaraDB RDS | Connection usage | 95th percentile | Real-time | All instances |
| ApsaraDB RDS | Disk usage | 95th percentile | Real-time | All instances |
| Object Storage Service (OSS) | Total outbound traffic over the Internet in the current month | Sum | The cumulative value from 00:00 on the first day of the month to the current time | All buckets |
| OSS | Total number of PUT requests in the current month | Sum | The cumulative value from 00:00 on the first day of the month to the current time | All buckets |
| OSS | Total number of GET requests in the current month | Sum | The cumulative value from 00:00 on the first day of the month to the current time | All buckets |
| OSS | Storage size | Sum | The sum of the storage occupied by all OSS buckets | All buckets |
| CDN | Total traffic in the current month | Sum | The cumulative value from 00:00 on the first day of the month to the current time | Total domains |
| CDN | Peak network bandwidth | 95th percentile | Real-time | Total domains |
| CDN | Queries per second (QPS) | 95th percentile | Real-time | Total domains |
| ApsaraDB for MongoDB | CPU utilization | 95th percentile | Real-time | All instances |
| ApsaraDB for MongoDB | Memory usage | 95th percentile | Real-time | All instances |
| ApsaraDB for MongoDB | IOPS usage | 95th percentile | Real-time | All instances |
| ApsaraDB for MongoDB | Connection usage | 95th percentile | Real-time | All instances |
| ApsaraDB for MongoDB | Disk usage | 95th percentile | Real-time | All instances |
| ApsaraDB for Memcache | Cache hit ratio | 95th percentile | Real-time | All instances |
| ApsaraDB for Memcache | Cache usage | 95th percentile | Real-time | All instances |
| ApsaraDB for Redis | Memory usage | 95th percentile | Real-time | All instances |
| ApsaraDB for Redis | IOPS usage | 95th percentile | Real-time | All instances |
| ApsaraDB for Redis | Connection usage | 95th percentile | Real-time | All instances |
| Elastic IP Address (EIP) | Inbound bandwidth | 95th percentile | Real-time | All instances |
| Elastic IP Address (EIP) | Outbound bandwidth | 95th percentile | Real-time | All instances |
| Container Service | CPU utilization | 95th percentile | Real-time | All instances |
| Container Service | Memory usage | 95th percentile | Real-time | All instances |
| Container Service | Outbound traffic over the Internet | 95th percentile | Real-time | All instances |
| Log Service | Total inbound traffic in the current month | Sum | The cumulative value from 00:00 on the first day of the month to the current time | All projects |
| Log Service | Total outbound traffic in the current month | Sum | The cumulative value from 00:00 on the first day of the month to the current time | All projects |
| Log Service | Total number of requests in the current month | Sum | The cumulative value from 00:00 on the first day of the month to the current time | All projects |
Statistical method: the 95th percentile.
- A percentile is a measure used in statistics. It indicates the value lower than which a given percentage of observations in a group of observations in ascending order falls.
- The 95th percentile is the value lower than which 95% of observations in a group of observations in ascending order falls. For example, if the 95th percentile for the CPU usage of ECS instances is 34%, 95% of the ECS instances have a CPU usage of lower than 34%.