When you use the
HttpWebRequest class to send lots of data by using a POST or PUT request, the
request may fail on a computer that is running the Microsoft .NET Framework.
Additionally, you may receive an out-of-memory or time-out error message.
If you do not receive an out-of-memory or time-out error message, you
may notice that the application that uses the
HttpWebRequest class uses lots of memory. When you use Performance Monitor to
monitor the application that uses the
HttpWebRequest class, the Private Bytes count will continue to increase as data
is sent. Therefore, you may also experience slow performance on the computer
and in other applications because increased memory and resource utilization
occurs.
Note The amount of data that can be uploaded by default will vary
according to the memory and the resources that are available on the
computer.
This issue occurs because the .NET Framework buffers the
outgoing data by default when you use the
HttpWebRequest class.
To work around this issue, set the
HttpWebRequest.AllowWriteStreamBuffering property to
false. However, you may receive an error message that is similar to the
following when you set the
HttpWebRequest.AllowWriteStreamBuffering property to
false:
This request requires buffering of data for
authentication of redirection to be successful.
To successfully send
lots of data by using a POST or PUT request when the
HttpWebRequest.AllowWriteStreamBuffering property is set to
false, use one of the following methods, depending on the
authentication method that you want to use.
Anonymous authentication
If the Web server is configured to use Anonymous authentication,
set the
HttpWebRequest.AllowWriteStreamBuffering property to
false. No other changes are needed.
Basic authentication
If the Microsoft Internet Information Services (IIS) Web server is
configured to use Basic authentication, and you must set the
HttpWebRequest.AllowWriteStreamBuffering property to
false, you must send a HEAD request to pre-authenticate the connection
before you send the POST or PUT request. You must also set the
HttpWebRequest.PreAuthenticate property to
true. Then, send the POST or PUT request, and then receive the
response. To do this, use code that is similar to the following code example.
public void test(Uri URL)
{
HttpWebRequest WRequest;
HttpWebResponse WResponse;
//preAuth the request
// You can add logic so that you only pre-authenticate the very first request.
// You should not have to pre-authenticate each request.
WRequest = (HttpWebRequest)HttpWebRequest.Create(URL);
// Set the username and the password.
WRequest.Credentials = new NetworkCredential(user, password);
WRequest.PreAuthenticate = true;
WRequest.UserAgent = "Upload Test";
WRequest.Method = "HEAD";
WRequest.Timeout = 10000;
WResponse = (HttpWebResponse)WRequest.GetResponse();
WResponse.Close();
// Make the real request.
WRequest = (HttpWebRequest)HttpWebRequest.Create(URL);
// Set the username and the password.
WRequest.Credentials = new NetworkCredential(user, password);
WRequest.PreAuthenticate = true;
WRequest.UserAgent = "Upload Test";
WRequest.Method = "POST";
WRequest.AllowWriteStreamBuffering = false;
WRequest.Timeout = 10000;
FileStream ReadIn = new FileStream("c:\\testuploadfile.txt", FileMode.Open, FileAccess.Read);
ReadIn.Seek(0, SeekOrigin.Begin); // Move to the start of the file.
WRequest.ContentLength = ReadIn.Length; // Set the content length header to the size of the file.
Byte[] FileData = new Byte[ReadIn.Length]; // Read the file in 2 KB segments.
int DataRead = 0;
Stream tempStream = WRequest.GetRequestStream();
do
{
DataRead = ReadIn.Read(FileData,0,2048);
if (DataRead > 0) //we have data
{
tempStream.Write(FileData,0,DataRead);
Array.Clear(FileData,0, 2048); // Clear the array.
}
}while(DataRead > 0);
WResponse = (HttpWebResponse)WRequest.GetResponse();
// Read your response data here.
// Close all streams.
ReadIn.Close();
tempStream.Close();
WResponse.Close();
}
Note Depending on how the application is designed, you may not have to
pre-authenticate each request by sending a HEAD request.
Integrated Windows authentication
You can configure a computer on which IIS is installed to respond
by using Negotiate or NTLM Windows authentication. If IIS is configured to use
Negotiate for Windows authentication, the client can use either Kerberos or
NTLM to authenticate. If IIS is configured to use NTLM authentication, only
NTLM authentication can be used, and Kerberos authentication is not
supported.
If Negotiate with Kerberos authentication is used, use the
following workaround. The workaround will fail if NTLM is used.
Negotiate with Kerberos authentication
If the IIS Web server is configured to use Negotiate
authentication and you must set the
HttpWebRequest.AllowWriteStreamBuffering property to
false, you must send a HEAD request to pre-authenticate the connection
before you send the POST or PUT request. You must also set the
HttpWebRequest.PreAuthenticate property to
true. Additionally, you may have to set the
HttpWebRequest.UnsafeAuthenticatedConnectionSharing property to
true. Then, send the POST or PUT request, and then receive the
response. To do this, you can use code that is similar to the following code
example.
Note This workaround will fail if the client cannot use Kerberos with
Negotiate authentication. You also must make sure that the
HttpWebRequest.KeepAlive property is set to
true. By default, the setting for the
HttpWebRequest.KeepAlive property is
true. The logic for Kerberos and Basic authentication is almost the
same.
public void test(Uri URL)
{
HttpWebRequest WRequest;
HttpWebResponse WResponse;
CredentialCache myCredCache = new CredentialCache();
myCredCache.Add(URL,"Negotiate",(NetworkCredential) CredentialCache.DefaultCredentials);
// Pre-authenticate the request.
WRequest = (HttpWebRequest)HttpWebRequest.Create(URL);
// Set the username and the password.
WRequest.Credentials = myCredCache;
// This property must be set to true for Kerberos authentication.
WRequest.PreAuthenticate = true;
// Keep the connection alive.
WRequest.UnsafeAuthenticatedConnectionSharing = true;
WRequest.UserAgent = "Upload Test";
WRequest.Method = "HEAD";
WRequest.Timeout = 10000;
WResponse = (HttpWebResponse)WRequest.GetResponse();
WResponse.Close();
// Make the real request.
WRequest = (HttpWebRequest)HttpWebRequest.Create(URL);
// Set the username and the password.
WRequest.Credentials = myCredCache;
// This property must be set to true for Kerberos authentication.
WRequest.PreAuthenticate = true;
// Keep the connection alive.
WRequest.UnsafeAuthenticatedConnectionSharing = true;
WRequest.UserAgent = "Upload Test";
WRequest.Method = "POST";
WRequest.AllowWriteStreamBuffering = false;
WRequest.Timeout = 10000;
FileStream ReadIn = new FileStream("c:\\ testuploadfile.txt ", FileMode.Open, FileAccess.Read);
ReadIn.Seek(0, SeekOrigin.Begin); // Move to the start of the file.
WRequest.ContentLength = ReadIn.Length; // Set the content length header to the size of the file.
Byte[] FileData = new Byte[ReadIn.Length]; // Read the file in 2 KB segments.
int DataRead = 0;
Stream tempStream = WRequest.GetRequestStream();
do
{
DataRead = ReadIn.Read(FileData,0,2048);
if (DataRead > 0) // We have data.
{
tempStream.Write(FileData,0,DataRead);
Array.Clear(FileData,0, 2048); // Clear the array.
}
}while(DataRead > 0);
WResponse = (HttpWebResponse)WRequest.GetResponse();
// Read your response data here.
// Close all streams
ReadIn.Close();
tempStream.Close();
WResponse.Close();
}
Note Depending on how the application is designed, you may not have to
pre-authenticate each request by sending a HEAD request.
NTLM authentication
If the IIS Web server is also configured to use NTLM
authentication with Windows Integrated authentication, and you must set the
HttpWebRequest.AllowWriteStreamBuffering property to
false, you can set the authentication type to NTLM in the client code.
After you configure IIS to use both Negotiate and NTLM authentication and you
set the authentication type to NTLM in the client code, you can configure how
IIS handles authentication requests by setting the
AuthPersistSingleRequest property in the IIS metabase to
false.
Note For more information about how to configure IIS to support both
Negotiate and NTLM authentication, see the "References" section.
You
must also send a HEAD request to pre-authenticate the connection before you
send the POST request and set the
HttpWebrequest.UnsafeAuthenticatedConnectionSharing property to
true. Then, set the
HttpWebRequest.PreAuthenticate property to
false. Finally, send the POST or PUT request, and then receive the
response. To do this, use code that is similar to the following code example.
public void test(Uri URL)
{
HttpWebRequest WRequest;
HttpWebResponse WResponse;
CredentialCache myCredCache = new CredentialCache();
myCredCache.Add(URL,"NTLM",(NetworkCredential) CredentialCache.DefaultCredentials);
// Pre-authenticate the request.
WRequest = (HttpWebRequest)HttpWebRequest.Create(URL);
// Set the username and the password.
WRequest.Credentials = myCredCache;
// For NTLM authentication, you must set the following property to true
// so the connection does not close.
WRequest.UnsafeAuthenticatedConnectionSharing = true;
WRequest.UserAgent = "Upload Test";
WRequest.Method = "HEAD";
WRequest.Timeout = 10000;
WResponse = (HttpWebResponse)WRequest.GetResponse();
WResponse.Close();
// Make the real request.
WRequest = (HttpWebRequest)HttpWebRequest.Create(URL);
// Set the username and the password.
WRequest.Credentials = myCredCache;
// For NTLM authentication, you must set the following property to true
// so the connection does not close.
WRequest.UnsafeAuthenticatedConnectionSharing = true;
WRequest.UserAgent = "Upload Test";
WRequest.Method = "POST";
WRequest.AllowWriteStreamBuffering = false;
WRequest.Timeout = 10000;
FileStream ReadIn = new FileStream("c:\\ testuploadfile.txt", FileMode.Open, FileAccess.Read);
ReadIn.Seek(0, SeekOrigin.Begin); // Move to the start of the file.
WRequest.ContentLength = ReadIn.Length; // Set the content length header to the size of the file.
Byte[] FileData = new Byte[ReadIn.Length]; // Read the file in 2 KB segments.
int DataRead = 0;
Stream tempStream = WRequest.GetRequestStream();
do
{
DataRead = ReadIn.Read(FileData,0,2048);
if (DataRead > 0) // We have data.
{
tempStream.Write(FileData,0,DataRead);
Array.Clear(FileData,0, 2048); // Clear the array.
}
}while(DataRead > 0);
WResponse = (HttpWebResponse)WRequest.GetResponse();
// Read your response data here.
// Close all streams.
ReadIn.Close();
tempStream.Close();
WResponse.Close();
}
Note Depending on how the application is designed, you may not have to
pre-authenticate each request by sending a HEAD request.
For more information about the
HttpWebRequest.AllowWriteStreamBuffering property, visit the following Microsoft Developer Network (MSDN)
Web site:
For more information about the
HttpWebRequest.PreAuthenticate property, visit the following MSDN Web site:
For more information about the
HttpWebRequest.UnsafeAuthenticatedConnectionSharing property, visit the following MSDN Web site:
For more information about Microsoft Negotiate authentication,
visit the following MSDN Web site:
For more information about Microsoft NTLM authentication, visit
the following MSDN Web site:
For more information about the
AuthPersistSingleRequest property in the IIS metabase, visit the following Microsoft Web
site:
For more information about delays in response to a
Web service request that may occur when you use NTLM authentication, click the
following article number to view the article in the Microsoft Knowledge Base:
331020Â
(http://kbalertz.com/Feedback.aspx?kbNumber=331020/
)
Delay in response to a Web service request when you use NTLM authentication
For more information about how to
configure IIS to use both Kerberos and NTLM authentication, click the following
article number to view the article in the Microsoft Knowledge Base:
215383Â
(http://kbalertz.com/Feedback.aspx?kbNumber=215383/
)
How to configure IIS to support both the Kerberos protocol and the NTLM protocol for network authentication
For more
information about issues that may occur when you negotiate Kerberos
authentication after you upgrade to Microsoft Internet Explorer 6, click the
following article number to view the article in the Microsoft Knowledge Base:
299838Â
(http://kbalertz.com/Feedback.aspx?kbNumber=299838/
)
Unable to negotiate Kerberos authentication after upgrading to Internet Explorer 6
For more
information about how to modify the metabase to control authentication
persistence, click the following article number to view the article in the
Microsoft Knowledge Base:
318863Â
(http://kbalertz.com/Feedback.aspx?kbNumber=318863/
)
How to modify the AuthPersistence metabase entry controls when clients are authenticated