Diagnosing the cause of slow page loading can be challenging. To address this problem, the slow session tracing feature of ARMS browser monitoring provides a performance waterfall chart for static resource loading. This feature lets you examine resource loading details to diagnose the root cause and quickly resolve the issue.
Problem
Slow page loading is a common and critical issue for front-end developers. The main challenges in diagnosing and resolving this problem include:
Difficulty in reproduction
When a user visits your webpage, the page load time is affected by their region, network, browser, and ISP. These factors make it difficult to replicate the exact session conditions for troubleshooting.
Lack of detailed monitoring data
Most browser monitoring tools use the PerformanceTiming object to obtain the full page load time. This approach, however, often omits data on individual static resource loading, making it difficult to identify the exact performance bottleneck.
Solution
To quickly identify performance bottlenecks, connect your web application to ARMS browser monitoring, enable page resource reporting during integration, and then use the slow session tracing feature.
Step 1: Connect to ARMS browser monitoring
By default, the browser monitoring agent does not report information about static resources on a page. You must enable this data collection to use the slow session tracing feature.
To connect your web application to ARMS browser monitoring, see Install an agent for a web page.
To use the slow session tracing feature, you must select Enable Page Resource Reporting during integration.
Step 2: Identify the issue
You can use either of the following methods with the slow session tracing feature to diagnose web performance problems.
Method 1: Start from the Page Speed page
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Log on to the ARMS console. In the left-side navigation pane, choose .
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On the Browser Monitoring page, select a region in the top navigation bar and click the name of the application that you want to manage.
In the left-side navigation pane, choose .
For more information about the Access speed page, see Page speed. In this example, the page performance is poor, with a full page load time of 36.7s at 11:00.
On the Access speed page, scroll down to the Slow Page Session Trace (TOP20) section.
This section lists the 20 slowest loading sessions for the page within the specified time range.
In this example, you can see that a session at 11:36:46 had a page load time of 36.72s. This indicates that this specific session is the cause of the spike in load time.
In the Slow Page Session Trace (TOP20) section, click the target page name in the Page column.
The Slow Loading Details page appears.
Use the information on the Slow Loading Details page to determine the root cause and resolve the issue.
The Page Information area at the top of the Slow Loading Details page displays information about the visit, such as the client IP address, browser, and operating system, to help you determine the cause of the failure.
This section also provides performance and environment information, including the Page URL, access Time, Full Page Load Time, DOM parsing time, and UA (User Agent).
The Page Resource Loading Waterfall section on the Slow Loading Details page displays a waterfall chart for static resource loading. This chart helps you quickly identify performance bottlenecks.
For more information about the Slow Loading Details page, see Slow session tracing.
Method 2: Start from the Session Traces page
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Log on to the ARMS console. In the left-side navigation pane, choose .
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On the Browser Monitoring page, select a region in the top navigation bar and click the name of the application that you want to manage.
In the left-side navigation pane, choose .
The Session List section displays all sessions for the application. You can filter the sessions by username, user ID, or session ID to quickly find sessions with long load times.
In the Session List section, click the target session name. Then, use the information on the Session Tracking Details page to determine the root cause and resolve the issue.
For more information about the Session Tracing page, see Slow session tracing.
The slow session tracing feature helps you replicate a user's session and identify performance bottlenecks by showing detailed resource loading conditions.
Related operations
Instead of retroactively diagnosing issues, you can proactively create alerts. Use the alert feature in ARMS to create alert rules for specific or all APIs. This immediately notifies your operations team when an issue occurs.
For instructions on creating an alert rule, see Browser monitoring alert rules (New version).