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HBase >> mail # dev >> LIRS cache as an alternative to LRU cache

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Re: LIRS cache as an alternative to LRU cache

You're correct.  The existing algorithm is called an Adaptive Replacement
Cache.  However, note that this cache does need some proper tuning for
optimal efficiency.


On 2/21/12 12:09 PM, "Vladimir Rodionov" <[EMAIL PROTECTED]> wrote:

>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
>From: Nicolas Spiegelberg [[EMAIL PROTECTED]]
>Sent: Tuesday, February 21, 2012 9:01 AM
>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.
>On 2/21/12 8:26 AM, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote:
>>Shall we experiment with low inter-reference recency set replacement
>>policy to see if block cache becomes more effective ?
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