SMDS Usage attributes (z/OS systems only)

Use the SMDS Usage attributes to get the shared message data set (SMDS) buffer pool usage information for each application structure that is currently using SMDS support.

The SMDS Usage attributes are available for QSG environment on z/OS® systems only.

Block Size The size of each buffer in KB. It is equal to the logical block size of the shared message data set.

CF Struct Name The name of the coupling facility application structure.

Empty Buffers The number of buffers that are free and empty.

In Use Buffers The number of buffers that are currently being used by requests to transfer data to or from the data set.

Lowest Free The smallest number of free buffers during the current statistics interval. A value of zero indicates all buffers were used but no request had to wait for an empty buffer. A negative value indicates the maximum number of requests that were waiting for a free buffer at the same time.

Offloaded Messages The number of shared messages in the structure for which the message data has been stored in the data set that is owned by the queue manager.

Origin Node The IBM MQ Monitoring agent-assigned name of the node on which the data for the queue manager originates.

QMgr Name The name of the queue manager.

Reads Saved % The percentage of read requests (during the current statistics interval) where the correct block was found in a saved buffer, avoiding the need to read the data from the data set.

Saved Buffers The number of buffers that are free but currently contain saved data for recently accessed blocks.

Total Blocks The current total size of the owned data set in logical blocks, including blocks that are used to store the space map.

Total Buffers The actual number of buffers in the pool.

Total Data Blocks The number of blocks in the owned data set that can be used to store data, excluding those used to store the space map.

Used Data Blocks The number of blocks in the owned data set that are currently in use. It is one or more pages of those blocks that contain active message data.

Used Part % The ratio of the number of used data blocks to the total data blocks, expressed as a percentage.

Wait Rate % The fraction of requests to acquire a buffer that had to wait for a free buffer, expressed as a percentage.