A deeper understanding of how the buffer pool performs can be gleaned through constant monitoring of several parameters in MySQL’s InnoDB status reports. Let’s look at some key indicators that help in assessing the efficiency of the buffer pool:
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 | ---------------------- BUFFER POOL AND MEMORY ---------------------- Total memory allocated 52747567104; in additional pool allocated 0 Total memory allocated by read views 6696 Internal hash tables (constant factor + variable factor) Adaptive hash index 1264159888 (815987752 + 448172136) Page hash 3188312 (buffer pool 0 only) Dictionary cache 218963057 (203998672 + 14964385) File system 1623040 (812272 + 810768) Lock system 127518328 (127499608 + 18720) Recovery system 0 (0 + 0) Dictionary memory allocated 14964385 Buffer pool size 3145712 Buffer pool size, bytes 51539345408 Free buffers 16385 — IF NEAR 0 - BUFFER POOL IS FULL Database pages 3101973 Old database pages 1144736 Modified db pages 0 Pending reads 0 — IF CONSISTENTLY GREATER THAN 0 - BUFFER MAY BE TOO SMALL Pending writes: LRU 0, flush list 0, single page 0 — IF CONSISTENTLY GREATER THAN 0 - BUFFER MAY BE TOO SMALL OR DISK IS SLOW FOR AMOUNT OF WRITES YOU HAVE Pages made young 6420249, not young 2000664705 0.13 youngs/s, 0.00 non-youngs/s Pages read 21996954, created 7754528, written 10606607 — IF written CONSISTENTLY GREATER THAN read - BUFFER IS TOO SMALL 0.00 reads/s, 0.00 creates/s, 0.33 writes/s Buffer pool hit rate 1000 / 1000, young-making rate 25 / 1000 not 0 / 1000 — IF hit rate CONSISTENTLY NOT 1000 / 1000 - BUFFER IS TOO SMALL, IF young-making rate CONSISTENTLY NOT 0 / 1000 - BUFFER IS TOO SMALL Pages read ahead 0.00/s, evicted without access 0.00/s, Random read ahead 0.00/s — IF evicted without access CONSISTENTLY GREATER THAN 0 - BUFFER IS TOO SMALL LRU len: 3101973, unzip_LRU len: 0 I/O sum[720]:cur[0], unzip sum[0]:cur[0] |