These statistics are for the queue index buffer pool, which is used to read and write queue index entries plus the associated data if the total queue size does not exceed 32K bytes. Buffers containing recently accessed queue index entries are added to a least recently used chain. This means that if another request for the same queue arrives shortly afterwards, it may be possible to optimize the processing based on the assumption that the copy in the buffer is probably already correct. If all other buffers are in use, a request for a new buffer will discard the contents of the least recently used buffer and reuse the storage as a free buffer. The queue server does not use some of the AXM management functions (such as KEEP or PURGE) so those counters will be zero. These fields describe the current state of the buffer pool.
The statistics are described in detail in the DFHXQS2D data area. The individual fields have the following meanings:
Statistic name | Field | Description |
---|---|---|
Buffers: Total | S2BFQTY | Number of buffers in the pool. |
Buffers: Max used | S2BFENTH | Highest number ever used (not affected by reset). |
Buffers: Active | S2BFACTS | Buffers currently in use. |
Buffers: On LRU | S2BFLRUS | Buffers with valid contents on LRU chain to allow reuse. |
Buffers: Empty | S2BFEMPS | Buffers previously used but now empty. |
Requests: Gets | S2BFGETS | Requests to get a buffer. |
Requests: Puts | S2BFPUTS | Put back buffer with valid contents |
Requests: Keep | S2BFKEPS | Keeps (put back buffer with modified contents). |
Requests: Free | S2BFFRES | Requests to put back a buffer as empty. |
Requests: Purges | S2BFPURS | Request to discard contents of a previously valid buffer. |
Results (Get): Got hit | S2BFHITS | Buffer requests that found a valid buffer. |
Results (Get): Got free | S2BFGFRS | Buffer requests that used a free buffer. |
Results (Get): Got new | S2BFGNWS | Buffer requests that obtained a buffer not previously used. |
Results (Get): Got LRU | S2BFGLRS | Buffer requests that discarded and reused the oldest valid buffer. |
Results (Get): No buf | S2BFGNBS | Buffer requests that returned no buffer. |
Error: Not freed | S2BFFNOS | A request tried to release a buffer it did not own. (This can occur during error recovery). |
Error: No purge | S2BFPNFS | A purge request did not find a matching buffer. |
Error: Not owned | S2BFPNOS | A purge request hit a buffer owned by another task. |
Wait: Pool lock | S2BFPWTS | Waits on buffer pool lock. |
Wait: Buf lock | S2BFLWTS | GET wait on buffer lock. |