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From Jeff Jirsa <>
Subject Re: EC2 storage options for C*
Date Mon, 01 Feb 2016 01:35:24 GMT
Also in that video - it's long but worth watching

We tested up to 1M reads/second as well, blowing out page cache to ensure we weren't "just"
reading from memory

Jeff Jirsa

> On Jan 31, 2016, at 9:52 AM, Jack Krupansky <> wrote:
> How about reads? Any differences between read-intensive and write-intensive workloads?
> -- Jack Krupansky
>> On Sun, Jan 31, 2016 at 3:13 AM, Jeff Jirsa <> wrote:
>> Hi John,
>> We run using 4T GP2 volumes, which guarantee 10k iops. Even at 1M writes per second
on 60 nodes, we didn’t come close to hitting even 50% utilization (10k is more than enough
for most workloads). PIOPS is not necessary. 
>> From: John Wong
>> Reply-To: ""
>> Date: Saturday, January 30, 2016 at 3:07 PM
>> To: ""
>> Subject: Re: EC2 storage options for C*
>> For production I'd stick with ephemeral disks (aka instance storage) if you have
running a lot of transaction.
>> However, for regular small testing/qa cluster, or something you know you want to
reload often, EBS is definitely good enough and we haven't had issues 99%. The 1% is kind
of anomaly where we have flush blocked.
>> But Jeff, kudo that you are able to use EBS. I didn't go through the video, do you
actually use PIOPS or just standard GP2 in your production cluster?
>>> On Sat, Jan 30, 2016 at 1:28 PM, Bryan Cheng <> wrote:
>>> Yep, that motivated my question "Do you have any idea what kind of disk performance
you need?". If you need the performance, its hard to beat ephemeral SSD in RAID 0 on EC2,
and its a solid, battle tested configuration. If you don't, though, EBS GP2 will save a _lot_
of headache.
>>> Personally, on small clusters like ours (12 nodes), we've found our choice of
instance dictated much more by the balance of price, CPU, and memory. We're using GP2 SSD
and we find that for our patterns the disk is rarely the bottleneck. YMMV, of course.
>>>> On Fri, Jan 29, 2016 at 7:32 PM, Jeff Jirsa <>
>>>> If you have to ask that question, I strongly recommend m4 or c4 instances
with GP2 EBS.  When you don’t care about replacing a node because of an instance failure,
go with i2+ephemerals. Until then, GP2 EBS is capable of amazing things, and greatly simplifies
>>>> We gave a talk on this topic at both Cassandra Summit and AWS re:Invent: It’s very much a viable option, despite any
old documents online that say otherwise.
>>>> From: Eric Plowe
>>>> Reply-To: ""
>>>> Date: Friday, January 29, 2016 at 4:33 PM
>>>> To: ""
>>>> Subject: EC2 storage options for C*
>>>> My company is planning on rolling out a C* cluster in EC2. We are thinking
about going with ephemeral SSDs. The question is this: Should we put two in RAID 0 or just
go with one? We currently run a cluster in our data center with 2 250gig Samsung 850 EVO's
in RAID 0 and we are happy with the performance we are seeing thus far.
>>>> Thanks!
>>>> Eric
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