Analyze the cause of Service Unavailable

  
                  

First, if the "Service Unavailable" prompt appears, you can access it after a few refreshes.

This happens because your website exceeds the iis limit.

Because the 2003 operating system prompts IIS too much, it is not like the 2000 system prompts "too many links", It is a prompt "ServiceUnavailable". This happens because the website exceeds the system resource limit, mainly because the program occupies too much resources.

For example, the same 100-person online forum, the resources of the Leo Forum are more than 10 times the resources of the PW Forum; in addition, some infinite loop programs, or programs that are not optimized, will take up too many systems. Resources, while system resources are clearly limited. However, the operating system of WINDOWS2003, each website runs in an independent process and does not affect each other.

If a website's program occupies too many resources or too many errors occur, the system log will prompt: "Application pool 'xxx' is automatically disabled because the process is served for this application pool There is a series of errors, or the prompt: the application pool 'xxx' has exceeded its job limit setting. At this time, access to this website will prompt: ServiceUnavailable. Generally, the system will return to normal in about 30 seconds, and it will be refreshed several times. Normal access.

In addition, if your website currently has too many visitors, which exceeds the system's iis connection limit, ServiceUnavailable will also appear (when there are too many connections under the win2k host, you will be prompted: Too many, please try again later; and the win2003 host just prompts: ServiceUnavailable)

Second, there is no restriction on IIS connection, or encounter Service Unavailable

is more common in the website using ACCESS database < Br>

Generally using windows2003IIS6 users may have this problem has been normal system, suddenly there is a website can not open
Tip: ServiceUnavailable but this site and There are restrictions on the number of IIS connections. Then it immediately affected other websites. In less than a moment, other websites have all become ServiceUnavailable
What is the reason?//This article comes from www.45it.com
We After analysis, you can know that it is still an old problem of MS. The ACCESS engine is gone. Use the server doctor's file doctor to fix it. When you look at the repair result, you will find some files causing the ACCESS engine to "catastrophic failure" and "not setting the object reference to the object." Instance" error. After the file doctor fixes, the system will return to normal.

Third, when browsing a Windows SharePoint Services Web site, the prompt: ServiceUnavailable

1. Microsoft Internet Information Service (IIS) 6.0 This issue may occur if the application pool for the virtual server is not configured correctly.

Solutions

To resolve this issue, follow these steps: 1. Verify that it is The virtual server is configured with an application pool. The default application pool is MSSharePointPortalAppPool.

Follow these steps to determine which application the virtual server is using. Program pool.

a. Click Start, point to Administrative Tools, and then click Internet Information Services (IIS) Manager.
b. Expand ServerName and expand Web Site, right-click the virtual server, and then click Properties.
c. Click the "Home Directory" tab. The application pools configured for the virtual server are listed in the Application Pools 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 described in the "Symptoms" section of this article after you reassign a new password to this account.

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

4. Restart IIS to recycle application pool

ServiceUnavailable"

ServiceUnavailable is generally insufficient resources, such as IIS, CPU or memory. Br>

All of our virtual hosts do not limit IIS, so we can eliminate IIS.

All of our server operating systems are windows2003, there is a key thing is "application pool" < Br>

In general, 30-50 stations share a program pool. This program pool can be simply understood as a resource library, that is, 30-50 stations share this resource. We limit the CPU usage of a program pool to 60%, memory usage is 200M.

If this resource is used up by one of the stations, the program pool will stop, and all stations using this program pool will have a "ServiceUnavailable" resource shortage prompt until The program pool is restarted.

In most cases, 60% of the CPU and 200M of memory are fully used; if there is a garbage program or an attack, there may be a sudden increase in CPU or a large amount of memory usage. Is the majority of "ServiceUnavailable The reason for the occurrence. From the current situation of our monitoring, most of the CPU usage is between 90% and 100%.

1, what about “ServiceUnavailable”?

We Developed a set of programs that specifically monitor and repair IIS. It automatically checks IIS every 10 minutes. If it finds that the program pool is stopped, it will restart. Therefore, once "ServiceUnavailable" appears, it will automatically repair up to 10 minutes. In most cases, it only takes 2-5 minutes. Most other companies do not have monitoring procedures, but they can only be repaired by hand. The general duration is 2-6 hours to discover and start.

2, Frequent What should I do if “ServiceUnavailable” appears?

If this prompt appears frequently, it indicates that one of the stations sharing resources with you has a problem, please contact our technician for troubleshooting.

3. Is "ServiceUnavailable" a server problem?

A lot of people think that the server is unstable, but it is not. If it is a server problem, there will be no "ServiceUnavailable" prompt, but straight Get rid of, even FTP can not go up.

This is because there are a lot of resources consumed by the station, the server resources are always limited, if the value exceeds the set value for a long time, the server will automatically stop the program pool. To prevent users from affecting other program pools.

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