CSNW Clients May Cause Clipper Index Corruption

• Microsoft Windows NT Workstation version 3.51
• Microsoft Windows NT Server version 3.51

SYMPTOMS

Clipper applications that are run on a Windows NT client using Client Services for NetWare (CSNW) may corrupt Clipper database index files maintained on a Novell or Novell-compatible server.

CAUSE

In some cases, a file with a read-associated cache can become old when a write overlaps the read cache.

The corruption is caused by old data being read in from the read cache; Clipper then uses that data to build the index file. For example, the following sequence on reads and writes results in index corruption:

1. A Clipper application builds a database and index from data set 1.

2. The Clipper application reads data set 2.

3. The Clipper application reads the database file with data set 1 and caches it.

4. The Clipper application writes to the database with data from data set 2.

5. The Clipper application re-reads the database with data from set 1 using the stale read cache.

6. The Clipper application builds the incorrect index file from the stale database read from the cache.

STATUS

Microsoft has confirmed this to be a problem in Window NT version 3.51. This problem was corrected in the latest U.S. Service Pack for Windows NT Workstation or Server version 3.51. For information on obtaining this update, query on the following word in the Microsoft Knowledge Base (without the spaces):

   S E R V P A C K

MORE INFORMATION

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