Possible Network Data Corruption If Locking Not Used (152186)
The information in this article applies to:
This article was previously published under Q152186 SYMPTOMS
When you use certain programs to access a common data file over the
network from multiple workstations, the data may be read incorrectly or
may become damaged.
CAUSE
The Microsoft Client for Microsoft Networks and Microsoft Client for
NetWare Networks cache some network data on the client computer for
enhanced network performance. If the program does not use locking calls to
guarantee data synchronization and integrity, this cached data may not be
kept in synchronization with the data on the network server.
If an opened file is not locked, it may be cached by the client. If the
file is then modified by a second client, the first client may read
incorrect file data from the cache, instead of reading the current file
data from the network server. Subequent writes by the first client may
result in incorrect data being written to the file, and damage to the file
data.
RESOLUTION
Contact the program's manufacturer for additional information about using
the program with Windows 95.
STATUS
This problem no longer occurs in Windows 98. To resolve this problem, install the current version of Windows. For information about the current version of Windows, visit http://www.microsoft.com/windows.
MORE INFORMATION
When locking calls are not used, the integrity of data cannot be
guaranteed by a network client that employs caching for enhanced
performance. Such network clients include the Microsoft Client for
NetWare Networks and the Microsoft Client for Microsoft Networks included
in Windows 95.
If a program locks the file or range of bytes that it intends to read from
or write to, the server locks that file, or that range of the file. This
denies access to that data to other users, and forces the client to read
the current data from the server instead of from the cache. This technique
is advised for maintaining data integrity when required, while providing
the performance benefits of caching when it is safe to do so.
| Modification Type: | Major | Last Reviewed: | 9/1/2006 |
|---|
| Keywords: | KB152186 |
|---|
|