BUG: Variables @@IDLE, @@CPU_BUSY, @@IO_BUSY Inaccurate

• Microsoft SQL Server version 4.2a for OS/2

SYMPTOMS

Under SQL Server 4.2a, the SP_MONITOR stored procedure will under-report CPU_BUSY, IO_BUSY, and IDLE. The sum of the percent time usage of these three variables will never add up to over 50 percent, whereas they should always add up to roughly 100 percent. These statistics are reported properly by version 4.2 of SQL Server.

CAUSE

Under SQL Server 4.2a, the values reported by the global variables @@IDLE, @@CPU_BUSY, and @@IO_BUSY will be about 1/2 their actual values. This is caused by an error in the system variable calculation routine in determining how much time has elapsed during the period for which activity is being measured.

Further rounding errors within the SP_MONITOR stored procedure can lead to the sum of CPU_BUSY, IO_BUSY, and IDLE percentages being less than 50 percent.

WORKAROUND

By doubling the numbers reported by SP_MONITOR for @@IDLE, @@CPU_BUSY, and @@IO_BUSY percentages, a relatively accurate report on system resource use can be obtained. Because OS/2 supplies no operating system services to report the CPU and IO use of processes, these statistics should be viewed only as a rough indication of actual system resource use.

STATUS

Microsoft has confirmed this to be a problem in SQL Server version 4.2a for OS/2. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.