Hi Enis,
Good ideas ! And hbase community is driving on these 2 items.
1) [HBASE-7404]: L1/L2 block cache
2) [HBASE-5263] Preserving cached data on compactions through cache-on-write

Thanks a lot
From: Enis Söztutar [[EMAIL PROTECTED]]
Sent: Monday, March 25, 2013 11:24 AM
To: hbase-user
Cc: lars hofhansl
Subject: Re: Does HBase RegionServer benefit from OS Page Cache

Thanks Liyin for sharing your use cases.

Related to those, I was thinking of two improvements:
 - AFAIK, MySQL keeps the compressed and uncompressed versions of the blocs
in its block cache, failing over the compressed one if decompressed one
gets evicted. With very large heaps, maybe keeping around the compressed
blocks in a secondary cache makes sense?
 - A compaction will trash the cache. But maybe we can track keyvalues
(inside cached blocks are cached) for the files in the compaction, and mark
the blocks of the resulting compacted file which contain previously cached
keyvalues to be cached after the compaction. I have to research the
feasibility of this approach.

On Sun, Mar 24, 2013 at 10:15 PM, Liyin Tang <[EMAIL PROTECTED]> wrote: