PRB: Slow SQL Server Connections Using Named Pipes with Win 95
Article ID: 156430
Article Last Modified on 12/3/2003
APPLIES TO
- Microsoft SQL Server 4.21a Standard Edition
- Microsoft SQL Server 6.0 Standard Edition
- Microsoft SQL Server 6.5 Standard Edition
- Microsoft Windows 95
This article was previously published under Q156430
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: kbfix kbinterop kbpipes kbnetwork kbdocfix kbipc kbprb KB156430