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From Ja Sam <>
Subject Re: Possible problem with disk latency
Date Wed, 25 Feb 2015 16:29:16 GMT
I do NOT have SSD. I have normal HDD group by JBOD.
My CF have SizeTieredCompactionStrategy
I am using local quorum for reads and writes. To be precise I have a lot of
writes and almost 0 reads.
I changed "cold_reads_to_omit" to 0.0 as someone suggest me. I used set
compactionthrouput to 999.

So if my disk are idle, my CPU is less then 40%, I have some free RAM - why
SSTables count is growing? How I can speed up compactions?

On Wed, Feb 25, 2015 at 5:16 PM, Nate McCall <> wrote:

>> If You could be so kind and validate above and give me an answer is my
>> disk are real problems or not? And give me a tip what should I do with
>> above cluster? Maybe I have misconfiguration?
> You disks are effectively idle. What consistency level are you using for
> reads and writes?
> Actually, 'await' is sort of weirdly high for idle SSDs. Check your
> interrupt mappings (cat /proc/interrupts) and make sure the interrupts are
> not being stacked on a single CPU.

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