A Quick Troubleshooting Method for Unable to Access the Website Running in the ECS Instance

Problem Description

• When you access a website running in an ECS instance, you may encounter the following problems:

• Prompts "not filed or not accessed", "website content does not match the filed information".

• Unable to log into Pagoda panel.

• The browser prompts "403", "404", "502", "503" and other numerical errors.

• Setting up a website for the first time and not being able to access the website.

• Sudden inaccessibility while the website continues to function.

• Websites in ECS instances cannot be accessed through SLB.

• Unable to access CDN-accelerated websites.

• Websites protected by a Web Application Firewall (WAF) cannot be accessed.

• Websites on cloud hosting are inaccessible.

Problem Causes

There are many reasons for not being able to access the website running on the ECS instance. Here are some common causes of problems. The specific reasons are subject to the on-site investigation results.

• TCP port 80 is not available.

• Web service is unavailable.

• The website is not registered.

• There is an anomaly in website resources or backend services.

• The site building process is not standard.

• Problems with the origin site itself.

Note There are many related factors and symptoms that cause website access exceptions. If you need to know more about the reasons why websites cannot be accessed in ECS instances, please refer to Troubleshooting and Guidelines When Accessing ECS Instances Are Abnormal.

Troubleshooting method

There are many phenomena and reasons why the website running in the ECS instance cannot be accessed. You can choose any of the following methods to quickly troubleshoot the problem.

Selecting solutions through problem phenomena

For the common problems listed below, you can quickly choose the corresponding problem solutions.

• Prompts "not filed or not accessed", "website content does not match the filed information".

Regardless of whether the website provides external services through IP addresses or domain names, it is not allowed to open website access services before the filing is successful. Please record your website IP or domain name.

• Unable to log into Pagoda panel.

It may be that the pagoda service is not running or the security group rule for the corresponding port of the pagoda service has not been added.

• The browser prompts "403", "404", "502", "503" and other numerical errors.

When the browser prompts a digital error, it usually indicates that the network between the client and the server is normal, but there are abnormalities in the website resources or back-end services.

• Setting up a website for the first time and not being able to access the website.

Make sure you follow the standard website building process.

• Sudden inaccessibility while the website continues to function.

You need to check the ECS instance status, web service, or backend database separately.

a. Check the status of the ECS instance

You can use the ECS self-diagnosis tool to check, and then operate according to the prompts in the diagnosis result.

b. Checks for web services or backend databases

Please make sure the web service and backend database are running. If it doesn't run, check the log and fix it according to the error message in the log.

• Websites in ECS instances cannot be accessed through SLB.

If there is a load balancing SLB in front of the ECS instance, the monitoring policy setting of the SLB instance may be abnormal.

• Unable to access CDN-accelerated websites.

You need to first determine whether it is a problem with the origin site itself.

• Websites protected by a Web Application Firewall (WAF) cannot be accessed.

You need to first judge whether it is a problem with the origin site itself, and then judge whether it is a problem of WAF interception by mistake.

• Websites on cloud hosting are inaccessible.

If you are not using an ECS instance but a cloud virtual host, you need to check the cloud virtual host.