How to solve linux 503 error

Solutions to Linux 503 errors: 1. Increase the number of IIS connections; 2. Repair server files; 3. Correctly configure the application pool; 4. Apply CDN; 5. Switch system services, etc.

The operating environment of this article: linux5.9.8 system, Dell G3 computer.

How to solve linux 503 error?How to solve linux server 503? What is 503 service unavailable?

Recently, a customer website had a "service unavailable" situation, and asked for help to solve it quickly. The responsible technology did not take long to help them solve the problem quickly. Lao Mo also searched the Internet for this problem and found that Service Unavailable is a system warning prompt. Mainly because a website's program takes up too many resources or too many errors occur, the system log will prompt: "Application pool 'xxx' is automatically disabled because a series of errors occurred in the process that provides services for this application pool. Error" or prompt: "Application pool 'xxx' has exceeded its job limit setting." At this time, when accessing this website, you will be prompted: Service Unavailable. In fact, the error situation of 503 service unavailable on the website is not complicated. It is mainly divided into the following situations, and everyone can solve them according to their own situation.

1. 503 service unavailable appears when accessing, but you can access normally after refreshing.

This situation occurs because the website exceeds the IIS limit. For example, when the 2003 operating system prompts that there are too many IISs, it does not prompt "Too many people connected" like the 2000 system, but prompts "Service Unavailable". This situation occurs because the website exceeds the system resource limit, mainly because the program takes up resources. too much.

Solution: Increase the number of IIS connections to solve the problem.

2. The number of IIS connections is not limited, but 503 service unavailable will be prompted.

This situation is usually caused by websites using the ACCESS database. Through analysis, you can know that the ACCESS engine is down. Through troubleshooting, it will be found that some files cause "catastrophic failure" of the ACCESS engine and "object reference not set to an instance of the object" error.

Solution: It can be restored to normal by repairing it through the file doctor of the server doctor.

3. When browsing a Windows SharePoint Services Web site, it prompts: Service Unavailable

The reason for this problem is that Microsoft Internet Information Services (IIS) 6.0 is not correctly configured for virtualization. The server's application pool.

Solution:

1. First, we need to verify whether the application pool is correctly configured on the virtual server. The default application pool is MSSharePointPortalAppPool.

a). Click "Start" select "Administrative Tools" and then click "Internet Information Services (IIS) Manager".

b). Open "ServerName", expand "Web Site", right-click the virtual server, and then click "Properties".

c). Click the "Home Directory" tab, and the application pool configured for the virtual server is listed in the "Application Pool" box.

d). Click "OK".

2. Verify that the application pool account is a member of the IIS_WPG group and the STS_WPG group on the server.

3. Restart IIS to recycle the application pool.

4. If the "service unavailable" problem occurs on the website for the first time, just restart IIS. The steps are as follows:

1. Use the shortcut key Windows R to open Run and enter iisreset to restart IIS.

2. Search for IIS in the start menu, then open IIS, and then choose to restart IIS.

5. The website often shows service unavailable503, or it still hangs after restarting IIS

1. Apply CDN

First You need to rule out whether the server or vps resources are sufficient, and check whether all the resources of your server are at normal values (cpu, bandwidth, memory, etc.). Nowadays, vps or servers have background panel statistics. You will be 100% CPU in the long term. There must be a problem. When your hardware resources are not idle, IIS will not work properly and will report some messy errors. In fact, a relatively simple solution is to add CDN to website access. After adding CDN, all the server resources needed by the website will be available. After using CDN, the IIS load has also been reduced, so no errors will be reported.

2. Turn off some unnecessary software functions

For example, many webmasters use SafeDog to protect their websites. The software is indeed good, but it can cause lags. In addition, if your security level is set to default or very high, a lot of interceptions will be made, sometimes from several to a dozen per second, which also consumes your server.

3. Website programming issues

If interactivity is not important during website operation, make the website static. It is more laborious to run dynamically under IIS, especially PHP

4. Switch system services

If the website is still using the iis system or apache/nginx built on win, it is recommended to switch to the linux system. In fact, linux is not that difficult. It is recommended to install php with one click on amh or pagoda. environment, and then use winsp (a visual management tool similar to ftp) to manage files and permissions.

Recommended learning: "PHP Video Tutorial" "linux Video Tutorial"

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