Cause analysis and solution of Service unavailable

The appearance service unavailable mainly in the following several aspects?

First, if the "Service unavailable" prompts, a few refreshing and can be accessed.
This occurs because your Web site is exceeding the IIS limit. Because 2003 of the operating system in the hint of IIS is not like the 2000 system prompts "too many links", but prompted "Service unavailable", this situation occurs because the site is more than the system resource constraints caused by the main program to occupy too much resources.
For example, the same 100-person online forum, the Forum's resources are the PW forum accounted for more than 10 times times the resources; In addition, some dead loop program, or not optimized program will occupy too much system resources, and system resources are obviously limited. However, the WINDOWS2003 operating system, the Web site is running in a separate process, will not affect each other.
If a Web site has too many programs or too many errors, the system log prompts: "Application pool ' xxx" is automatically disabled because of a series of errors in the process serving the application pool, or because the application pool ' xxx ' exceeds its job restriction setting. At this point, visit this site will be prompted: Service unavailable. The general system will return to normal in about 30 seconds, more than a few times can be normal access to refresh.

In addition, if your site currently has too many visitors, more than the system's IIS connection limit, there will be a service unavailable (Win2K host too many connections will be prompted: Too many connections, please try again later While the Win2003 host just directly prompts: Service unavailable)

Two, not restricting IIS connections, or encountering service unavailable.
       is more common in Web sites that use an Access database. Users who typically use Windows 2003 IIS 6 may have this problem with a normal system, and suddenly a website is not open, prompting: Service unavailable But this site does not limit the number of IIS connections. Then immediately affect other sites, less than a while, other sites are all turned into Service unavailable. What's the reason?
       We can know after analysis, or MS's old problem. The access engine was. With the server doctor's file Doctor repair, when you view the fix results, you will find some files that caused the access engine to "catastrophic failure" and "not set object references to instances of objects." The system will not return to normal until the file doctor fixes it.

Third, when browsing a Windows SharePoint Services Web site, prompt: Service unavailable
       This problem may occur when the application pool for the virtual server is not configured correctly in Microsoft Internet information Services (IIS) 6.0.
       To resolve this issue, follow these steps:
        1, Verify that the application pool has been configured for the virtual server. The default application pool is MSSharePointPortalAppPool.
       Follow these steps to determine which application pool the virtual server is using.
A. Click Start, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.
B. Expand ServerName, expand Web Sites, right-click the virtual server, and then click Properties.
C. Click the Home Directory tab. The application pool configured for the virtual server is listed in the Application pool box.
D. Click OK.
       2, verify that the password used by the application pool account is correct. IIS does not automatically poll for password changes in the Active Directory directory service. If the application pool account is a domain account and its password has expired, you may receive the error message that is described in the "Symptoms" section of this article after you reassign a new password for this account.
       3, verify that the application pool account is a member of the IIS_WPG and STS_WPG groups on the server.
       4, restart IIS to recycle application pools

Note: IIS refers to the number of Windows or links that your Web site opens at the same time, opening a window that occupies one IIS.

Service Unavailable Problems and solutions
Some servers or Web site virtual host, such as access often appear Service unavailable prompts.

Windows 2003 Server system prompts for service unavailable due to excessive number of connections or exhaustion of system resources. This is often the case if you want to upgrade the virtual host or server configuration.

If you make a reasonable IIS setting. This can be better avoided. Make the following settings on the server.

1. IIS application Pool--Properties--The Recycle worker process is set for 15 minutes-60 minutes;

2, memory recovery of the following two options before all tick;

3, health--Enable fast failure protection option will be checked out;

Troubleshoot Windows Server 2003 server virtual host database site users log in minutes after landing automatically exit, need to log back to the problem: the IIS application Pool--Properties--The Recycle worker process is set for 15 minutes-60 minutes.

Service Unavailable (stop services) problem

Why does our website often appear "Service Unavailable" (stop services) prompt, refresh several times can visit or even can't visit?

Reason:
The Web site program itself bugs (such as dead loops), improperly set (such as opening some unnecessary, but resource-consuming functions), doing some special operations (such as generating HTM operations), and Web site IIS, or other services to restart (just for a moment), exceeding resource constraints, The number of IIS online exceeds the limit (Universal 200m server 20 concurrency, standard 1g Type 100 concurrency), exceeding the cup10% limit (converting static HTML, etc.).

Workaround:
Modify the program, check the program error, you can put the program to the local application, check CPU memory consumption
Try not to open those unnecessary functions, not only to ensure that the site fast enough, but also to ensure server stability
Special operations try to avoid peak periods and operate locally.
If a similar error occurs frequently, please optimize the website program in time, or upgrade your virtual host to a higher type,
To get more system resources.