服务不可用几大原因（Service Unavailable几大原因）（Several reasons for the unavailability of services (Service, Unavailable, several major reasons)）

服务不可用几大原因（Service Unavailable几大原因）（Several reasons for the unavailability of services (Service, Unavailable, several major reasons)） 服务不可用几大原因(Service Unavailable几大原因)(Several reasons for the unavailability of services (Service, Unavailable, several major reasons)) Service Unavailable for several reasons: Reason 1: the site exceeds the number of IIS connections Solution 1: increase the number of IIS connections Note 1: the Windows 2003 operating system prompts IIS for too long, not as prompted by the Win2000 system as "too many links", but rather "Service Unavailable"" Reason two: the site exceeds the IIS resource limit Solution two: increase the resources of the website Note two: in Winodws2003, the site takes more than IIS to limit the system resources of the site, and directly prompts "Service Unavailable"" Reason three: the site of the program too much error Solution three: modify program errors Note three: Winodws2003 website too many mistakes, it will cause the site where the application pool is wrong, this time you can see the application pool'xxx'is automatically disabled in the Windows2003 log, the reason is a series of mistakes "for the application pool to provide services in the process, this time the website will directly show" Service Unavailable" The above three reasons caused by "Service Unavailable", the general phenomenon is the emergence of "Service Unavailable", after more than a few times to refresh, you can open. Fourth Service Unavailable situation, just installed IIS appeared Service, Unavailable, are not in those three kinds of inside, so on the server view solution. Because of the new IIS server, in general, the problem can not be in the IIS itself, the emergence of such problems, generally from the permissions to consider, first consider the IIS service startup account, there is no authority to start IIS. Click "start", "Settings", "control panel" - "management tools" - "service", open the local service manager, IIS Admin found Service, double-click to open the IISADMIN attribute, select the "landing" tab display login identity for the local system account, the IISADMIN services have no access problems. Click "start", "Settings", "control panel" - "management tools" - "service", open the local service manager, World Wide Web Publishing find Service, double-click to open W3SVC service attributes, select the "landing" tab, landing a display for the local system account, the W3SVC services have no access problems. Here, in order to make it easier to operate, the service operation is re - opened From here you can exclude the service startup account without permission to start, and go back to the ultimate solution. Phenomenon: click "start", "Settings", "control panel" - "management tools" -- "event viewer, open event viewer, click the" system ", see a lot of warnings and errors, mainly are the following: 1) is the source of "W3SVC", ID "1002" error description is "application pool'DefaultAppPool'is automatically disabled, because of a series of errors for the application pool to provide services in the process of." 2) the source is "W3SVC" and the event ID is "1009", a warning that the process that provides service for the application pool'DefaultAppPool'terminates unexpectedly. The process ID is'1756'. The process exit code is'0xffffffff'." 3) is the source of "DCOM", ID "10016" error description is "application specific permission settings to the COM server application (CLSID {A9E69610-B80D-11D0-B9B9-00A0C922E750}) local activation of the NT AUTHORITY\NETWORK SERVICE SID grant (S-1-5-20). You can modify this security authority using the component services management tool." Analysis: the determination should be third ID "10016" DCOM error caused event ID 1009 application pool accident exit through these events, causing the event ID 1002 application pool is automatically disabled W3SVC error, Here's the solution. Problem determination: DCOM error prompted because NETWORK SERVICE user does not have permission to start {A9E69610-B80D-11D0-B9B9-00A0C922E750}, Found the reason, the following to solve this problem First find the corresponding CLSID{A9E69610-B80D-11D0-B9B9-00A0C922E750} service, click the "start" - "run", type "regedit" to start the registry editor, select the "my computer" in the registry editor on the left side of the tree, and then use the shortcut key "Ctrl+F" to open the search dialog box, enter the CLSID just in the "find": "{A9E69610-B80D-11D0-B9B9-00A0C922E750}" "check box, see" keep only "items", enter search task. To find the CLSID in the registry on the right side of the editor shows the CLSID information learned from this information, the CLSID IIS Admin Service is the corresponding service, now we can determine the NETWORK SERVICE IIS Admin Service the user does not have permission to start. Open the "start" - "control panel" - "management tools" - "service" - "computer" - "my computer" - "DCOM configuration" option to find "IIS Admin Service", the right key to select "properties", find "safe", in "activate permissions" in editing "custom", "NETWORK SERVICE," added account gives the "local start" and "local activation" permission, restart IIS. Restart IIS, open the page again, and now it has been displayed.