Hi all: I saw some interesting results from Hortonworks blog (block cache <http://zh.hortonworks.com/wp-content/uploads/2014/03/perfeval_blockcache_v2.pdf> ).
In this result, the ratio of memory footprint to database size is held fixed while the absolute values are increased. In my mind, the performance should becomes worse for larger ratio as the increase of the absolute value. For example BucketCache#(tmpfs), the difference between ratio (DB"1.5":"RAM"1.0) and ratio (DB"4.5":"RAM"1.0) becomes larger as the increase of memory. Actually, the result of ratio ( DB"1.5":"RAM"1.0) increase linearly, and the result of ratio (DB"1.5":"RAM"1.0) exponentially. However, for BucketCache#(heap) and LruBlockCache, the result is out of my expectation. The curves of ratio (DB"1.5":"RAM"1.0) and ratio (DB"4.5":"RAM"1.0) both increase exponentially, but the relative differences as the increase of memory are not consistent. Take LruBlockCache as an example, the difference of ratio (DB"1.5":"RAM"1.0) and ratio (DB"4.5":"RAM"1.0) becomes smaller from 20 GB to 50 GB, but becomes larger from 50 GB to 60 GB. How to analysis the cause of this result, any ideas? -- *Regards,* *Zhaojie*
