I have a very strange problem with post data being lost in transit. The log-in form for our ASP web app has a for submitting the username / password. The ASP page then receives this post, checks the credentials, and re-directs successful log ins. The problem I'm seeing is that intermittently the post data is just dropped. The request appears on the server, but there is no data. Client side is IE8, server side is IIS running ASP. The user will be fine for a time, and then as soon as they get his error, they have to restart the machine to solve it. What could be causing this and what type of diagnostics can I run to locate the problem?
Use Fiddler tool for inspecting client-server http communication. Maybe something is dropping data between client and server.
You can save each request which you receive in server in some file and to see if they really does not send you nothing. Try to see IIS log for error. Maybe your IIS is busy with other requests and refuse to accept this one. Than it will send 500 error to the client.
Related
So I'm working on a web server to host a website to talk to a teradata database, but every now and then when I send a request from the website back to the server, it will do nothing until I focus the console and press any key. Does anyone know why this is and how I can fix it?
I'm using XMLHttpRequests on the website and using the default Nodejs http package on the server side. Let me know if you need more information about it that I haven't included here.
As it turns out this was an issue with CMD/Powershell select mode.
I'm using Xamarin.Forms with azure and everything been working fine, but today I started getting this weird error - "The request could not be completed. (Internal Server Error)", the only thing that I know of that I've changed lately is the sql server password. So I'm wondering if that could be the issue of if it could be something else and how to fix it. The diagnostics tool is also showing http server errors whenever a request is attempted.
Ok, so I figured it out, sure enough it was the change in my sql server password, to fix it I simply changed it back to what it originally was.
I had written a mini App in asp classic this week. It worked perfectly on the test server connecting to the test data base. Then yesterday evening I moved it from the test server to the live server updating the connection strings to the live db.
I published it as an application to the default website in the default app pool. Then I tested it and it worked perfectly.
This morning however both myself and another user receive a 500 -internal Server error when we try and save changes to the database(there appears to be no issue reading from the db) yet my two other collogues have no issue at all.
Even more odd is that the same thing is happening on the test server where the code hasn't been changed in weeks. But this morning I cannot commit to the db from there either.
I have attempt to enable more detailed error tracking and logging but the property options for the server are seem unavailable when i tried to set up custom Active Server Pages (ASP) error pages off online tutorials.
The server is used by a lot of people so I was wondering is their a permission issue depending on the user that restricts writting to the database. Or something else that may have changed to allow some users to write data and others to receive the error.
Im very knew to IIS so it may be something glaringly obvious that I haven't considered.
Thanks
This article should help you:
In earlier versions of IIS, error messages from classic ASP scripts
were sent to a Web browser, by default. Because these error messages
might reveal sensitive information to malicious users, IIS 7 and above
disables this feature by default. When your classic ASP scripts
encounter an error in IIS, you receive the following error message by
default:
An error occurred on the server when processing the URL. Please contact the system administrator.
If you are the system administrator please click here to find out more about this error.
I am facing an issue on sending http request using wininet api using when the request is sent through a proxy server.
I have an mfc application which sends a requests to a server.
for sending request is use
HttpSendRequest
function of wininet.
I need a file to be uploaded using this. for that 3-4 requst has to be sent related to each file.
When there is a proxy i cant upload more than 3 files at a time.
After that the requests is not sent properly.
Once it is blocked all the requests sent after that doesn't get proper response(some exception occurs).
I have done adding proxy credentials using
InternetSetOption(hConnect, INTERNET_OPTION_PROXY_USERNAME, (LPVOID)lpUname, nUnameBuffer);
InternetSetOption(hConnect, INTERNET_OPTION_PROXY_PASSWORD, (LPVOID)lpPswrd, nPswrdBuffer);
when the application is restated then its ok for the next 3 files.
also its working fine if the proxy settings are disabled.
Any one know why this occurres?
is there any limit for request using wininet functions under a proxy?
please help how to solve this issue.
hellpp me plzzzzz
thanks in advance.
The MS Support article "How To Handle Proxy Authorization with WinInet" suggest that you need to respond to HTTP_STATUS_PROXY_AUTH_REQ with adding authentication data and re-sending the request.
I get this question a lot =/
But I only know how to answer it at a very high level.
From the minute a user enters a URL and hits enter, what happens on the client and server side, and how do requests/responses work? How does the server interact with CGI/interpreters?
It would be helpful too if you could direct me to a URL that has this information in detail, or if you can answer it.
When I describe this to people I always feel like theyre looking for specifics and I'm not giving enough detail.
Thanks!
Client initiates communication (Usually a HTTP GET request)
Server receives REQUEST-HEADER and parses the URL contained within.
Server does a lookup to see if any URL matches locally in a harddrive-folder. If the webserver handles virtual servers like a Microsoft IIS, then it will determin which folder to search after retrieving the "www.domain.com" part from the REQUEST header.
If web-document (HTML file) is found, then Server sends this back as RESPONSE + a HTTP status code (eg. 200 saying: found, this request went well, where as 404 is "didnt find that file")
Client (browser) receives RESPONSE and can now display it as it wants. If it contains a render engine, then it will search for patterns (HTML tags or whatever language) and then display it as such.
This is also called "stateless" as the server closes communication with client after the client has received everything from the reponse-stream.
Therefore the server cannot know if the client is still connected nor if its comming back later. Many servers does provide a session object using cookies or similar to track if its the same client that sends the next REQUEST and if so, allowing more "intelligent" server responses - such as seeking, transactions and logins.
How does the internet work?
HTTP Made Really Easy
The Canonical Document: RFC 2616
The client sends request headers to the server (finds the IP via DNS).
The server software (e.g. Apache) calls CGI if it needs to and prepares the response.
It sends headers back as well as the content.