Basic Concepts

Metrics

Metrics reflect resource performance data or status. A metric consists of a namespace, dimension, name, and unit.

Metric namespaces can be regarded as containers for storing metrics. Metrics in different namespaces are independent of each other so that metrics of different applications will not be aggregated to the same statistics information. Each metric has certain features, and a dimension may be considered as a category of such features. Figure 1 describes the relationships among namespaces, dimensions, and cluster metrics.

Figure 1 Cluster metrics

The metric storage duration and billing mode vary according to AOM editions. For details, see AOM Pricing Details.

Hosts

Each host of AOM corresponds to a VM or physical machine. A host can be your own VM or physical machine, or a VM (for example, an ECS) or physical machine (for example, a BMS) that you purchased on Huawei Cloud. A host can only be connected to AOM for monitoring when its OS is supported by AOM and an ICAgent has been installed on the host. (For details about the OSs supported by AOM, see OS Usage Restrictions.)

ICAgent

ICAgent is the collector of AOM. It runs on hosts to collect metrics, logs, and application performance data in real time. Before using AOM, ensure that the ICAgent has been installed. Otherwise, AOM cannot be used.

Logs

AOM supports log collection, search, analysis, download, and dump. It also reports alarms based on keyword statistics and enables you to export reports, query SQL statements, and monitor data in real time.

The log storage duration, size, and billing mode vary according to AOM editions. For details, see AOM Pricing Details.

Log Buckets

Log buckets are logical groups of log files. Before creating statistical rules or querying bucket logs, ensure that a log bucket has been created.

Log Traffic

Log traffic refers to the volume of logs reported per second. A maximum of 10 MB/s is supported for each tenant in a region. If the log traffic exceeds 10 MB/s, logs may be lost.

Bucket Logs

Bucket logs support fine-grained query. You can view logs by bucket to obtain key service data, and quickly identify and locate problems.

Bucket logs allow you to query logs from multiple dimensions. You can also query and analyze original logs, and structured logs based on SQL syntax.

Alarms

Alarms are reported when AOM or an external service such as ServiceStage, Application Performance Management (APM), or Cloud Container Engine (CCE) is abnormal or may cause exceptions. Alarms will cause service exceptions and need to be handled.

There are two alarm clearance modes:

• Automatic clearance: After a fault is rectified, AOM automatically clears the corresponding alarm, for example, a threshold alarm.
• Manual clearance: After a fault is rectified, AOM does not automatically clear the corresponding alarm, for example, ICAgent installation failure alarm. In such a case, manually clear the alarm.

Events

Events generally carry some important information. They are reported when AOM or an external service, such as ServiceStage, APM, or CCE encounters some changes. Such changes do not necessarily cause service exceptions. Events do not need to be handled.

Threshold Rules

Threshold rules: You can set threshold conditions for resource metrics. AOM reports a threshold alarm when the value of a metric reaches the preset threshold, or reports an insufficient data event when no metric data is reported. In addition, a custom trigger policy is executed. When the threshold rule status (Exceeded, OK, or Insufficient) changes, a notification is sent by email or SMS message. In this way, you can detect and handle exceptions at the earliest time.

Notification Rules

AOM provides the notification function. When an alarm is reported due to an exception in AOM or an external service, alarm information will be sent to the specified personnel by email or SMS message. Therefore, such personnel can rectify faults in time to avoid service loss.

Statistical Rules

AOM can periodically count keywords or SQL statements and generate metric data, enabling you to monitor system performance and service information in real time. You can also set threshold rules for metrics. AOM reports a threshold alarm when the value of a metric reaches the preset threshold. In this way, you can detect and handle exceptions at the earliest time.

Topologies

Topologies show the call and dependency relationships between services. A topology consists of circles, lines with arrows, and resources. Each circle represents a service, and each segment in the circle represents an instance. The fraction in each circle indicates the number of active instance/total number of instances. The values below a fraction respectively indicate the number of calls, latency, and number of errors. Each line with an arrow represents a call relationship. Thicker lines indicate more calls. The values above a line respectively indicate the throughput and total latency. Throughput indicates the number of calls within the selected period. Application Performance Index (Apdex) is used in topologies to quantify user satisfaction with application performance. Different colors indicate different Apdex ranges, helping you quickly detect and locate faults.

Figure 2 Topology

Transactions

In real life, a transaction is a one-time task. A user completes a task by using an application. For example, a product query in an e-commerce application is a transaction, and a payment is also a transaction. A transaction is usually an HTTP request (complete process: request > web server > database > web server > request).

Tracing

By tracing and recording service calls, AOM visually restores the execution traces and statuses of service requests in distributed systems, so that you can quickly locate performance bottlenecks and faults.