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From Alain RODRIGUEZ <arodr...@gmail.com>
Subject Re: Network / GC / Latency spike
Date Mon, 31 Aug 2015 13:56:44 GMT
I just realised that I have no idea about how this mailing list handle
attached files.

Please find screenshots there --> http://img42.com/collection/y2KxS

Alain

2015-08-31 15:48 GMT+02:00 Alain RODRIGUEZ <arodrime@gmail.com>:

> Hi,
>
> Running a 2.0.16 C* on AWS (private VPC, 2 DC).
>
> I am facing an issue on our EU DC where I have a network burst (alongside
> with GC and latency increase).
>
> My first thought was a sudden application burst, though, I see no
> corresponding evolution on reads / write or even CPU.
>
> So I thought that this might come from the node themselves as IN almost
> equal OUT Network. I tried lowering stream throughput on the whole DC to 1
> Mbps, with ~30 nodes --> 30 Mbps --> ~4 MB/s max. My network went a lot
> higher about 30 M in both sides (see screenshots attached).
>
> I have tried to use iftop to see where this network is headed too, but I
> was not able to do it because burst are very shorts.
>
> So, questions are:
>
> - Did someone experienced something similar already ? If so, any clue
> would be appreciated :).
> - How can I know (monitor, capture) where this big amount of network is
> headed to or due to ?
> - Am I right trying to figure out what this network is or should I follow
> an other lead ?
>
> Notes: I also noticed that CPU does not spike nor does R&W, but disk reads
> also spikes !
>
> C*heers,
>
> Alain
>

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