Because memory is needed by so many components in
SQL Server, and to make sure each component uses memory efficiently, SQL Server
uses a Memory Broker, whose job is to analyze the behavior of SQL Server with
respect to memory consumption and to improve dynamic memory distribution.
The Memory Broker is a centralized mechanism that dynamically distributes memory between the buffer pool, the query executor, the Query Optimizer, and all the various caches, and it attempts to adapt its distribution algorithm for different types of workloads. You can think of the Memory Broker as a control mechanism with a feedback loop. It monitors memory demand and consumption by component, and it uses the information that it gathers to calculate the optimal memory distribution across all components. It can broadcast this information to the component, which then uses the information to adapt its memory usage. You can monitor Memory Broker behavior by querying the Memory Broker ring buffer as follows:
The Memory Broker is a centralized mechanism that dynamically distributes memory between the buffer pool, the query executor, the Query Optimizer, and all the various caches, and it attempts to adapt its distribution algorithm for different types of workloads. You can think of the Memory Broker as a control mechanism with a feedback loop. It monitors memory demand and consumption by component, and it uses the information that it gathers to calculate the optimal memory distribution across all components. It can broadcast this information to the component, which then uses the information to adapt its memory usage. You can monitor Memory Broker behavior by querying the Memory Broker ring buffer as follows:
SELECT * FROM sys.dm_os_ring_buffers WHERE ring_buffer_type =
'RING_BUFFER_MEMORY_BROKER';
The
ring buffer for the Memory Broker is updated only when the Memory Broker wants
the behavior of a given component to change—that is, to grow, shrink, or remain
stable (if it has previously been growing or shrinking).
