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From Vladimir Rodionov <vrodio...@carrieriq.com>
Subject RE: LIRS cache as an alternative to LRU cache
Date Tue, 21 Feb 2012 17:09:32 GMT
afaik, existing LruBlockCache is not exactly LRU cache
It utilizes more advanced algorithm to avoid cache trashing during scan ops by
dividing cache into three sub-caches (for newly added blocks, for promoted blocks and for
in-memory blocks)


Best regards,
Vladimir Rodionov
Principal Platform Engineer
Carrier IQ, www.carrieriq.com
e-mail: vrodionov@carrieriq.com

________________________________________
From: Nicolas Spiegelberg [nspiegelberg@fb.com]
Sent: Tuesday, February 21, 2012 9:01 AM
To: dev@hbase.apache.org
Subject: Re: LIRS cache as an alternative to LRU cache

We had the author of LIRS come to Facebook last year to talk about his
algorithm and general benefits.  At the time, we were looking at
increasing block cache efficiency.  The general consensus was that it
wasn't an exponential perf gain, so we could get bigger wins from
cache-on-write intelligence, in-memory data compression techniques, and
adding stats so we could understand how to tune the existing LRU
algorithm.  I still think that these 3 goals are more important at the
moment because LIRS would be a decent bit of code and only incremental
gain.  It's probably something to revisit in a year or two.

Nicolas

On 2/21/12 8:26 AM, "yuzhihong@gmail.com" <yuzhihong@gmail.com> wrote:

>Hi,
>Shall we experiment with low inter-reference recency set replacement
>policy to see if block cache becomes more effective ?
>
>Cheers
>
>


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