SQL Server, Buffer Node Object

New: 5 December 2005

The Buffer Node object provides counters that complement counters provided by the Buffer Manager object. It allows you to monitor the SQL Server buffer pool page distribution for each non-uniform memory access (NUMA) node. There is an instance of the Buffer Node object for each NUMA node in use. On non-NUMA architecture there will be a single instance of the Buffer Node object.

This table describes the SQL Server Buffer Node performance objects.

SQL Server Buffer Node counters Description

Database pages

Number of pages in the buffer pool on this node with database content.

Foreign pages

Number of pages that come from a different NUMA node.

Free pages

Total number of free pages on this node.

Page life expectancy

Number of seconds a page will stay in the buffer pool on this node without references.

Stolen pages

Number of pages used for miscellaneous server purposes (stolen from the buffer pool) on this node.

Target pages

Ideal number of pages in the buffer pool on this node.

Total pages

Total number of committed pages in the buffer pool on this node.

If SQL Server is running on non-NUMA hardware, the counters of Buffer Node and Buffer Manager objects should match and the Foreign pages counter will be zero.

On NUMA hardware, sums of respective counters of all Buffer Nodes should match their counterparts of Buffer Manager.

The counter values and sums may not match precisely due to the dynamic nature of the counters and the sampling accuracy.

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