Response Monitor

The Monitor panel, located in the application view of the VIP Dashboard, displays an application’s HTTP response status code data from the most recent 24 hours in chart or table format.

Access

To access the Monitor panel:

1. Navigate to the VIP Dashboard for an application.
2. Select “Performance” from the sidebar navigation at the left of the screen.
3. Select “Monitor” from the submenu.

The Monitor panel is environment-specific (e.g., Production, Develop). Select a different environment from the dropdown at the upper left of the VIP Dashboard application view.

Display as Chart

Select “Display as Chart” from the dropdown menu located at the top right of the Monitor panel.

Response data is displayed in one-hour intervals and formatted in Coordinated Universal Time (UTC). Hover over a graphed line on the chart to view a breakdown of 4xx responses, 5xx responses, and Total Requests per hour.

Data is updated every 15 minutes. Depending on the current time, the latest interval in the chart may not represent a full hour of data.

Display as Table

Select “Display as Table” from the dropdown menu located at the top right of the Monitor panel.

Each row of the table displays the Total Requests made in a one-hour interval and a breakdown of the 4xx and 5xx responses. Times are formatted in Coordinated Universal Time (UTC).

Data is updated every 15 minutes. Depending on the current time, the last row of the table may not represent a full hour of data.

5xx responses

An HTTP 5xx response (e.g., 500, 501, 502, 503, 504) indicates an error on the server side. For example, a 500 response could result if an application’s server encounters a PHP fatal error and can no longer respond.

Possible causes for increased 5xx status responses from an application

• An unexpected strain on the servers, caused by recently deployed code.
• A sudden substantial increase in site traffic.
• A large number of site requests bypassing the page cache. Uncached SQL queries can overload the primary database, returning 503 responses.
• Plugins that generate inefficient SQL queries or trigger SQL-intensive cron tasks, not designed for an enterprise-scale site.
• Uncached WordPress functions.

4xx responses

HTTP 4xx responses (e.g., 400, 401, 402, 403, 404) signal an error on the client side. Most of the time, they do not indicate critical issues affecting a site. For example, if a user requests a page that does not exist, they will see a 404 Not Found error. Users who request access to an application behind IP restriction will see a 403 Forbidden status if their IP address is not allowed.

In some cases, a pattern of 404 responses may indicate a missing URL that needs to be redirected.

Debugging resources

Underlying causes for an increased volume of 5xx and 4xx responses might not be immediately apparent, and more in-depth debugging may be needed.

• If an environment has New Relic enabled, the New Relic Transaction traces and Errors dashboards may point towards underlying causes for an increase in 4xx or 5xx responses.
• View a snapshot of recent PHP Errors in the Logs tab of the Health panel in the VIP Dashboard or in the New Relic APM Errors dashboard.
• Analyze the logs provided by HTTP request Log Shipping for insight into connectivity issues, performance tuning, usage patterns, or service interruptions.