I am trying to receive an EDI message over AS2 from a partner. However partner is receiving two MDNs. One is postive MDN and that is fine. We are sending asynchronous MDN
Problem is they are receiving another unknown/unwanted/bad MDN along with postive MDN, and that contains only this in the MDN content.
Server: Microsoft-IIS/10.0
X-Powered-By: ASP.NET
Date: Wed, 15 Apr 2020 16:47:46 GMT
Content-Length: 0
Can anyone tell me how to resolve this?
It will be something in your set-up of the MDN generation... without seeing the configuration it is hard to say. It is possible that the incoming message is meeting the criteria for another trading partner enough to generate the bad MDN so you may have to check other trading partners as well. Check the raw content inbound and outbound to see what message properties are being matched etc. That is the best I can say without seeing the set up.
Related
I need to start by saying this isn't my server. I am however currently troubleshooting with the company that provides the server and its service. They've stated it's our "network", though, that seems vague.
While the 'Client' is running, I'll see on Fiddler;
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/ for "Ping"
then when the "408" error starts, I don't see the same "Envelope" message, it's completely blank.
After about 10 hours of the 'Client' being open, it will lose connection "408" to the Primary webservice and fail to the Backup webservice, never recovering to the Primary. After some time, it will also 408 on the Backup.
HTTP/1.1 408 Request body incomplete
Date: Sat, 22 Jan 2022 00:15:07 GMT
Content-Type: text/html; charset=UTF-8
Connection: close
Cache-Control: no-cache, must-revalidate
Timestamp: 19:15:07.511
The request body did not contain the specified number of bytes. Got 0, expected 129
I also see some
signalR/signalr/abort?
signalR/signalr/negotiate?
signalR/signalr/connect?
signalR/signalr/start?
signalR/signalr/abort?
The tech said it's the "fault of the Client", but, it's their Client. I was hoping someone may be able to help me figure out "who's" problem it really is. I do have a saved Fiddler capture if that's of interest.
Also to note, I have Windows Event Viewer errors that happen at the same time.
Error when trying to establish session on webservice with address:
http://enps8buddy/nomwebservices3/nomwebservice82.svc. Error:
System.OutOfMemoryException: Exception of type
'System.OutOfMemoryException' was thrown.
And
GenericWSErrHandler fired:
System.ServiceModel.EndpointNotFoundException: There was no endpoint
listening at http://enps8buddy/nomwebservices3/nomwebservice82.svc
that could accept the message. This is often caused by an incorrect
address or SOAP action. See InnerException, if present, for more
details. ---> System.Net.WebException: Unable to connect to the remote
server ---> System.Net.Sockets.SocketException: An operation on a
socket could not be performed because the system lacked sufficient
buffer space or because a queue was full
I don't fully understand how this all works; I'm learning as much as I can so I can mount a better case to support. Any insight or even a point in the right direction would mean a lot to me. Thank you in advance for any consideration and time you provide.
I understand that one can set Accept-Ranges: none on the server to advise the client not to attempt a range request.
I am wondering if there is a way to tell a browser not to attempt a range request without having to make any changes on the server.
For instance, is there a setting in Chrome or Firefox that I can toggle to deter my browser from making range requests?
You answered the question in the first sentence.
The relevant RFC is 7233, Hypertext Transfer Protocol (HTTP/1.1): Range Requests:
2.3. Accept-Ranges
A client MAY generate
range requests without having received this header field for the
resource involved.
A server that does not support any kind of range request for the
target resource MAY send
Accept-Ranges: none
to advise the client not to attempt a range request.
If you mean you want to know how to disable range requests in a browser altogether, consult the specific browser's documentation. A quick web search yielded no options for me to do this for common browsers.
Let's say i want to download a file called example.pdf from http://www.xxx.ууу/example.pdf
Probably, i send GET request like this:
GET /example.pdf HTTP/1.1␍␊
Host: www.xxx.yyy␍␊
␍␊
But what's next?
How does exchange of http headers look like?
I'm assuming you've read the Wikipedia article on the HTTP protocol. If you just need more examples I'd highly recommend you download Wireshark. Wireshark is an extremely powerful packet sniffer which will allow you to watch packet communications between you and any website. In addition it will actually break down the packets and tell you a little bit about their meanings in more "human terms". It has a bit of a learning curve but it can teach you a lot about a number of different protocols including HTTP.
http://www.wireshark.org/
I'm not sure what your ultimate goal is, but you can view real-time http header interaction with the Live HTTP Headers Firefox add-on. It's also possible in Chrome, but it's a little more work.
Check the HTTP 1.1 RFC.
You might want to look at http://www.w3.org/Protocols/rfc2616/rfc2616.html . But also, there is rarely a need to recreate the protocol.
To answer such GET request, the packet with the following header should be passed:
HTTP/1.1 200 OK
Accept-Ranges: bytes
Content-Length: 6475593
Content-Type: application/x-msdownload
Etag: "qwfw473usll"
Last-Modified: Sun, 18 Jul 2021 12:02:31 GMT
Server: Caddy
Date: Sun, 18 Jul 2021 12:03:47 GMT
After the last line, you must specify 2 CRLF and row bytes of the file to be transmitted.
We have often some issues in terms of interoperability on the Web. One of these issues for browsers vendors is the wrongly spelled Connection HTTP header. The most common errors are given by these two forms.
nnCoection:
Cneonction:
There are has been a few articles about this, including Fun with HTTP headers. Often it is happening by period, then disappear. It seems that some of them are created by load balancers such as this example: NetScaler Appliance.
Do you know any other instances of hardware or software that create these issues?
Update Here an example among others of a site which doesn't send back a good Connection HTTP header.
curl -sI ehg-nokiafin.hitbox.com
HTTP/1.1 200 OK
Date: Tue, 25 Jan 2011 20:35:45 GMT
Server: Hitbox Gateway 9.3.6-rc1
P3P: policyref="/w3c/p3p.xml", CP="NOI DSP LAW NID PSA ADM OUR IND NAV COM"
Cneonction: close
Pragma: no-cache
Cache-Control: max-age=0, private, proxy-revalidate
Expires: Tue, 25 Jan 2011 20:35:46 GMT
Content-Type: text/plain
Content-Length: 23
update 2011-01-26
On Amazon forum about AWS, there is a thread about nnCoection. A comment says:
FYI, the reason it misspells the word
connection is so that the internet
check-sum (a simple sum) still adds
up, this way the change can occur at
the packet level. If it completely
removed the header, it would have to
stall forwarding the response until
the header was entirely read, so it
could rewrite the headers, recompute
the checksum and then send it along.
with
sum(ord(c) for c in "Connection")
and
sum(ord(c) for c in "nnCoection")
both gives 1040
Are you sure it's an actual issue? The linked article suggests that these sorts of headers are "misspelled on purpose" so that a load balancer, reverse proxy or other middlebox can defeat the server's wishes that the connection be kept alive, without having to track a delta in TCP stream position over the life of the connection. Something like this may actually be necessary to bring a downed and recovered server back into active duty, by forcing kept-alive connections to other servers to migrate to the one brought online.
If you have a protocol that's dependent on HTTP Connection: keep-alive to function (cough), you're probably doing it wrong.
I'm writing a mobile application and I'm having difficulty downloading lengthy files from a Yahoo! server that periodically (about every three minutes) aborts the download. The mobile application successfully downloads lengthy files from other servers via the same slow data connection. A dump of the HTTP header from the Yahoo! server is
D/AsyncDownloadFile( 694): header fields: {p3p=[policyref="http://info.yahoo.co
m/w3c/p3p.xml", CP="CAO DSP COR CUR ADM DEV TAI PSA PSD IVAi IVDi CONi TELo OTPi
OUR DELi SAMi OTRi UNRi PUBi IND PHY ONL UNI PUR FIN COM NAV INT DEM CNT STA PO
L HEA PRE LOC GOV"], content-type=[application/octet-stream], connection=[close]
, last-modified=[Fri, 06 Aug 2010 14:47:50 GMT], content-length=[2000000], age=[
0], server=[YTS/1.17.13], accept-ranges=[bytes], date=[Sat, 07 Aug 2010 18:53:02
GMT]}
which shows it defines connection=[close]. A different (non Yahoo!) server defines connection=[keep-alive] and my mobile application successfully downloads from it. So I have a few questions: What is causing the Yahoo! server to periodically abort the downloads? What can I do to avoid the periodic aborting or what can I do to resume an aborted download? Are requests for byte ranges considered when the server defines connection=[close]?
Things I've read:
description of persistent connections,
description of byte range requests
Things I've tried:
I've tried setting the http header "Connection" field to "keep-alive" but the Yahoo! server response was a header "Connection" field set to "close".
I've tried resuming the connection as described in this question. Even though the HTTP header from the Yahoo! server shows that it supports byte range requests and the content range responses appear correct (e.g., content-range=[bytes 387924-1999999/2000000]), the resumed transfers incorrectly resume at the file start. I'm wondering if that is due to the connection=[close] setting.
Because the subject of HTTP headers is rather new to me, any suggestions or warnings about common pitfalls are welcome.
[UPDATE] I received a reply from Yahoo! tech support saying that byte range is not supported: "Yahoo! Web Hosting does not support Accept-range header since we work with a pool of servers and each request potentially reaches a different server. You will see connection=[close] in the response header indicating this." The remaining question is whether or not the periodic download abortions can be avoided. (I tried requesting Connection="keep-alive" but that was ignored.)
I received a reply from Yahoo! tech support explaining that byte range requests are not accepted: "Yahoo! Web Hosting does not support Accept-range header since we work with a pool of servers and each request potentially reaches a different server. You will see connection=[close] in the response header indicating this."
Given that resuming a download is not possible, I asked if it was possible to avoid the periodic aborting of downloads (e.g., Connection=[keep-alive]). The Yahoo! tech support reply: "the process is handled by the system and there is currently no work around."
While these are not the answers I would have liked, I give credit to Yahoo! tech support for fielding questions about the Yahoo! server behavior.