PRB: Slow SQL Server Connections Using Named Pipes with Win 95

• Microsoft SQL Server versions 4.2x, 6.0, 6.5
• Win32 Named Pipes

SYMPTOMS

When you run SQL Server applications on a computer running Windows 95, you may experience slow connections to Microsoft SQL Server using named pipes. This applies to both ODBC and DB-Library applications. The same applications will run normally on a computer running Windows NT, or using other interprocess communication (IPC) connections, such as TCP/IP sockets or SPX.

Also when reading data from a named pipe when the client is on Windows 95, calls to blocking ReadFile will not return immediately when there is no data present. When there is data present, a blocking read may take up to 1 second per message.

CAUSE

This problem is caused by Windows 95 NWLink Direct-Hosting, which was implemented to enhance the general network performance of Windows 95. A client using Direct-Hosting may experience a delay in reading from named pipes.

MORE INFORMATION

Direct-Hosting is enabled by default, so you may run into this problem if you have NWLink installed and configured as the default transport protocol. However, if you have other transport protocols loaded at the same time, you may not encounter this problem, because Windows 95 may use named pipes over other protocols, rather than NWLink IPX/SPX.

This problem does not occur with 16-bit Windows applications, because the 16-bit named pipes Net-Library for Windows peeks the named pipes first until data is available, and then begins to read. This method avoids the delay with Direct-Hosting in its own Peeknamedpipe messages.

Additional query words: DirectHosting netlib net-lib performance

Keywords : kbinterop kbnetwork kbdocfix kbIPC kbPipes kbSDKPlatform kbGrpNet
Version : winnt:4.2x,6.0,6.5; :
Platform : winnt
Issue type : kbprb