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From Mick Semb Wever <>
Subject Re: OOM opening bloom filter
Date Sun, 11 Mar 2012 23:22:27 GMT
On Sun, 2012-03-11 at 15:06 -0700, Peter Schuller wrote:
> If it is legitimate use of memory, you *may*, depending on your
> workload, want to adjust target bloom filter false positive rates:

This particular cf has up to ~10 billion rows over 3 nodes. Each row is
very small, <1k. Data from this cf is only read via hadoop jobs in batch
reads of 16k rows at a time. 

*-Data.db files are typically ~50G, and *-Filter.db files typically 2G
although some are 7Gb.
At the moment there are many pending compactions, but i can't do any
because the node crashes at startup.

It's my understanding then for this use case that bloom filters are of
little importance and that i can 
 - upgrade to 1.0.7
 - set fp_ratio=0.99
 - set index_interval=1024

This should alleviate much of the memory problems.
Is this correct?


"It seems that perfection is reached not when there is nothing left to
add, but when there is nothing left to take away" Antoine de Saint
Exupéry (William of Ockham) 

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