I've got a 2K box with IIS 5 and it's running about 40 sites. Every once in a while, DLLHOST.EXE (by IUSR_machine) will spike 100% and degrade the box until A) IIS is restarted or B) it's rebooted.

Anyone know why it does, or how to prevent IIS from doing this?

put your sites in high isolation to prevent one site killing others. and then try to pinpoint the problem

Very likely one of your clients is running a rogue script and hammering the server.

I trust the content as the users are small businesses. Now, I wouldn't rule out a Do: Loop in the script somewhere because of stupidity.

Do IIS web hosts typically isolate the sites, and do you have to isolate to throttle CPU usage?

"Do IIS web hosts typically isolate the sites"

Bad ones dont, good ones do.

Heres the low down > http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnserv/html/server112299.asp

Sam.

and CPU throttling:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnasdj01/html/asp0201.asp

this isolation thing makes me laugh. because all the time someone tries to explain why w2k servers are a bull**** they don't even KNOW about isolation.

if you want to be a good host:
- create a anonymous user per site
- isolate each site
- restrict use of components to authenticated users

we are not an host but we know hosts who get 1 month uptime with win2k (this is the best uptime you can get because you need to reboot at least once per month to upgrade win2k) and very good performance on entry level servers with 150 heavy sites on them.

win2k is not only plug and play. hosting is not a game. win2k is really a very stable server when you know what you are doing (and few win2k hosts know)

Bump.

I dont feel isolation on setup is strictly neccesary if you have the right monitoring but it is always a good idea. If you can catch rogue apps quickly then you can isolate them as and when needed. You then contact the responsible client and tell them to sort there code or they will be running with 1mb ram and 1% CPU ;)

it's very difficult to pinpoint problems if hosts are not isolated IMHO

Alain, do you use any 3rd party sware for process monitoring? I would be interested to know.

Thanks.
Sam.

It's messy now, we use IUSR for the anonymous user and Serv-U for people to FTP in. We weren't able to get IIS FTP to login to the user's folder and we were unable to find a FTP package that respected NTFS.

Creating an anonymous user per site sounds messy; could you create HostingPackage1 and HostingPackage2 anonymous users and run their isolated site as either HP1 or HP2, and then HP1 and HP2 would have access to features?

Originally posted by alain
this isolation thing makes me laugh. because all the time someone tries to explain why w2k servers are a bull**** they don't even KNOW about isolation.

if you want to be a good host:
- create a anonymous user per site
- isolate each site
- restrict use of components to authenticated users

we are not an host but we know hosts who get 1 month uptime with win2k (this is the best uptime you can get because you need to reboot at least once per month to upgrade win2k) and very good performance on entry level servers with 150 heavy sites on them.

win2k is not only plug and play. hosting is not a game. win2k is really a very stable server when you know what you are doing (and few win2k hosts know)