URL

This function monitors the calls of the current application by external services. It includes URL, Dubbo server, CSE server, CSEProvider cluster, and FunctionGraph monitoring. This type of monitoring item demonstrates the actual external status of the entire service. For example, if the average response time of a URL is long, it means that external users take a long time to query the corresponding data.

This section focuses on URL monitoring.

Going to the URL Page

Log in to the management console.
Click on the left and choose Management & Deployment > Application Performance Management.
In the navigation pane, choose Application Monitoring > Metrics.
In the tree on the left, click next to the target environment. On the URL tab page that is displayed, check URL monitoring information of all instances.
On the displayed URL tab page, select a target instance and monitoring item to view the monitoring data in different metric sets.
Select a time range. Default: Last 20 minutes.

Options: Last 20 minutes, Last hour, Last 3 hours, Last 6 hours, Last day, Today, Yesterday, Last week, Last month, or Custom.

Figure 1 Selecting a time range
Click in the upper right corner of the list and select the metric data you want to view.

Viewing URL Monitoring Data

URL summary

For common URL calls, the system collects the metrics of each URL. For details about the metrics, see Table 1.

**Table 1** Parameters of the URL summary
Metric Set	Metric	Description
URL summary	url	URL.
	method	Request HTTP method.
	Calls	Number of times that the URL is called.
	Avg RT (ms)	Average response time of the URL in a collection period.
	Errors	Number of call errors of the URL.
	Max Concurrency	Maximum concurrency of the URL.
	Max RT (ms)	Maximum response time of the URL in a collection period.
	Apdex	Application performance index (Apdex), which indicates users' satisfaction. The value ranges from 0 to 1. The closer the value is to 1, the higher the satisfaction is.
	Exceptions	Number of exceptions of the URL.
	0 ms–10 ms	Number of requests with 0 ms–10 ms response time.
	10 ms–100 ms	Number of requests with 10 ms–100 ms response time.
	100 ms–500 ms	Number of requests with 100 ms–500 ms response time.
	500 ms–1s	Number of requests with 500 ms–1s response time.
	1s–10s	Number of requests with 1s–10s response time.
	10s–n	Number of requests with response time longer than 10s.

URL invocation is the starting point of tracing. When you click a URL, the tracing page is displayed, showing the URL invocation condition in a certain period (default: 20 minutes).
You can add a URL for tracing by referring to Configuring URL Tracing.
Click a number in blue (such as those in the Calls or Avg RT (ms) column) to view more details.

Status code summary

APM supports status code-based summary. The system collects the metrics of each URL. For details about the metrics, see Table 2.

**Table 2** Parameters of status code summary
Metric Set	Metric	Description
Status code summary	code	Status code.
	Count	Number of times that the status code occurred.
	Latest URL	Sample URL which returns the status code in a collection period.

Click a status code in the code column. The tracing page is displayed, showing the invocation condition of the status code of the selected instance in the environment in last 20 minutes (default).
Click a number in the Count column to view the trend of the status code in a specified period.
Click the latest URL to view the invocation details of the corresponding status code.

Cluster summary

APM can summarize metrics by cluster. For details about the metrics, see Table 3.

**Table 3** Parameters of the cluster summary
Metric Set	Parameter	Description
Cluster summary	Cluster ID	Cluster ID of the caller.
	Calls	Number of times the cluster is called.
	Avg RT (ms)	Average response time in a collection period.
	Errors	Number of times that the cluster fails to be called.
	Max Concurrency	Maximum concurrency of the cluster.
	Max RT (ms)	Slowest call time in a collection period.

Click a number in blue (such as those in the Calls or Avg RT (ms) column) to view more details.

Overview

View the metric trend of the selected instance on the Overview tab page. For details about the metrics, see Table 4.

**Table 4** Overview metrics
Metric Set	Metric	Description
Overview	Total Requests	Total number of URL requests.
	Avg RT (ms)	Average response time of the URL.
	Errors	Total number of URL errors.
	Apdex	Users' satisfaction with the URL.