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From Benjamin Roth <benjamin.r...@jaumo.com>
Subject Re: High disk io read load
Date Fri, 17 Feb 2017 11:02:25 GMT
Hi Nate,

See here dstat results:
https://gist.github.com/brstgt/216c662b525a9c5b653bbcd8da5b3fcb
Network volume does not correspond to Disk IO, not even close.

@heterogenous vnode count:
I did this to test how load behaves on a new server class we ordered for
CS. The new nodes had much faster CPUs than our older nodes. If not
assigning more tokens to new nodes, what else would you recommend to give
more weight + load to newer and usually faster servers.

2017-02-16 23:21 GMT+01:00 Nate McCall <nate@thelastpickle.com>:

>
> - Node A has 512 tokens and Node B 256. So it has double the load (data).
>> - Node A also has 2 SSDs, Node B only 1 SSD (according to load)
>>
>
> I very rarely see heterogeneous vnode counts in the same cluster. I would
> almost guarantee you are the only one doing this with MVs as well.
>
> That said, since you have different IO hardware, are you sure the system
> configurations (eg. block size, read ahead, etc) are the same on both
> machines? Is dstat showing a similar order of magnitude of network traffic
> in vs. IO for what you would expect?
>
>
> --
> -----------------
> Nate McCall
> Wellington, NZ
> @zznate
>
> CTO
> Apache Cassandra Consulting
> http://www.thelastpickle.com
>



-- 
Benjamin Roth
Prokurist

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