Re: The state server has closed an expired TCP/IP connection

State server was configured as 'localhost', 127.0.0.1 would not have had this issue. I check by disassembling webengine4.dll. It returns something like 'connection closed by remote host' HRESULT 72746. But system.web interprets this as the session being locked by a concurrent query and keeps retrying at full speed. IMAP server closed the connection. Clock skew detected. Check the clock in the file server. This thread is locked. You can follow the question or vote as helpful, but. The resolution to this issue, after opening a case with Microsoft support, was to install and run SSLDiag and verify that there is an issue with the certificate that is generated automatically for the Office Server Web Service during the install of SharePoint. Once that is verified, install SelfSSL, remove the offending cert and create. This kind of issue may take place when a time-out value is set too low on the server or connected network device. To resolve this issue, see resolutions A, D, E, F, and O. This issue can also occur if the server makes the connection reset unpredictably, such as if an uncontrolled exception crashes the server function.

Dec 07, 2018 04:12 PM|Koenemoes|LINK

We have had this issue for a couple of months at seemingly random times and levels of severity. Last week I finally got the extra hint from a seemingly unrelated event.

We also saw a 100% CPU spike on at least 1 IIS app pool which brings down the whole server after a while.

IISRESET was our only solution and this would work.

Long story short: it happened during WSUS updates of our dc's. The AD resync after rebooting them took longer than the configured time window of 1 hour.

So the situation could arise that both DNS servers were offline -> so also no AD

State server was configured as 'localhost', 127.0.0.1 would not have had this issue. I check by disassembling webengine4.dll. It returns something like 'connection closed by remote host' HRESULT 72746.

Transmit Server Closed Connection

But system.web interprets this as the session being locked by a concurrent query and keeps retrying at full speed. This created an infinite loop of failing socket connections PER SESSION!

And that is why cpu got to 100%. It fills up the request queue, still waiting for the session data and then fajils completely with http 503 for all appools.

Our logs also showed connection issues to our sql because ad was down.

We were so focussed on the 100% cpu being the cause, but it was only a symptom. The fact that this error logged in event viewer was very misleading in my case.

In the end it was a quick 1 minute fix of the DC. -> no more emergency wake up calls for me :)

This was a perfect storm of timing events and small config mistakes which led to misleading logs and cpu spike by a asp.net bug...? Why keep retrying to read the session data if it won't work due to dns. Just end the webrequest there and log sometinhg like: NameResolution Failed instead of connection timeout

This article helps you resolve the FTP download session fails problem that occurs when FTP control connection is closed.

Original product version: Internet Information Services
Original KB number: 254722

Symptoms

If the control connection is closed during an FTP download session, the download from the IIS FTP site fails.

Note

This issue usually occurs when a firewall is in use that has been set to close the control connection if no TCP data is transferred after a certain amount of time.

Cause

Server Closed Connection

This is by design. RFC-959 states the following:

... The protocol requires that the control connections be open while data transfer is in progress. It is the responsibility of the user to request the closing of the control connections when finished using the FTP service, while it is the server who takes the action. The server may abort data transfer if the control connections are closed without command...

Workaround

To resolve this issue, try the following workarounds:

• Use an FTP utility or firewall setting that keeps the control connection open.
• Use a faster connection.
• Request that the FTP Site owner break the file that the download fails on into multiple, smaller files.

More information

This scenario usually occurs when you are downloading a large file over a slow connection.