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From Matija Gobec <matija0...@gmail.com>
Subject Re: EC2 instance recommendations
Date Tue, 23 May 2017 17:35:46 GMT
Exactly. You can easily build a solid backup/restore with snapshots and
automate it in case all hell breaks loose.
EBS volumes are expensive right now and with i3 you get much more IOPs and
a reasonable disk size for 1/2 or 1/3 the price.

Best,
Matija

On Tue, May 23, 2017 at 1:29 PM, Gopal, Dhruva <Dhruva.Gopal@aspect.com>
wrote:

> Thanks! So, I assume that as long we make sure we never explicitly
> “shutdown” the instance, we are good. Are you also saying we won’t be able
> to snapshot a directory with ephemeral storage and that is why EBS is
> better? We’re just finding that to get a reasonable amount of IOPS (gp2)
> out of EBS at a reasonable rate, it gets more expensive than an I3.
>
>
>
> *From: *Jonathan Haddad <jon@jonhaddad.com>
> *Date: *Tuesday, May 23, 2017 at 9:42 AM
> *To: *"Gopal, Dhruva" <Dhruva.Gopal@Aspect.com>, Matija Gobec <
> matija0204@gmail.com>, Bhuvan Rawal <bhu1rawal@gmail.com>
> *Cc: *"user@cassandra.apache.org" <user@cassandra.apache.org>
>
> *Subject: *Re: EC2 instance recommendations
>
>
>
> > Oh, so all the data is lost if the instance is shutdown or restarted
> (for that instance)?
>
>
>
> When you restart the OS, you're technically not shutting down the
> instance.  As long as the instance isn't stopped / terminated, your data is
> fine.  I ran my databases on ephemeral storage for years without issue.  In
> general, ephemeral storage is going to give you lower latency since there's
> no network overhead.  EBS is generally cheaper than ephemeral, is
> persistent, and you can take snapshots easily.
>
>
>
> On Tue, May 23, 2017 at 9:35 AM Gopal, Dhruva <Dhruva.Gopal@aspect.com>
> wrote:
>
> Oh, so all the data is lost if the instance is shutdown or restarted (for
> that instance)? If we take a naïve approach to backing up the directory,
> and restoring it, if we ever have to bring down the instance and back up,
> will that work as a strategy? Data is only kept around for 2 days and is
> TTL’d after.
>
>
>
> *From: *Matija Gobec <matija0204@gmail.com>
> *Date: *Tuesday, May 23, 2017 at 8:15 AM
> *To: *Bhuvan Rawal <bhu1rawal@gmail.com>
> *Cc: *"Gopal, Dhruva" <Dhruva.Gopal@Aspect.com>, "
> user@cassandra.apache.org" <user@cassandra.apache.org>
> *Subject: *Re: EC2 instance recommendations
>
>
>
> We are running on I3s since they came out. NVMe SSDs are really fast and I
> managed to push them to 75k IOPs.
>
> As Bhuvan mentioned the i3 storage is ephemeral. If you can work around it
> and plan for failure recovery you are good to go.
>
>
>
> I ran Cassandra on m4s before and had no problems with EBS volumes (gp2)
> even in low latency use cases. With the cost of M4 instances and EBS
> volumes that make sense in IOPs, I would recommend going with more i3s and
> working around the ephemeral issue (if its an issue).
>
>
>
> Best,
>
> Matija
>
> On Tue, May 23, 2017 at 2:13 AM, Bhuvan Rawal <bhu1rawal@gmail.com> wrote:
>
> i3 instances will undoubtedly give you more meat for buck - easily 40K+
> iops whereas on the other hand EBS maxes out at 20K PIOPS which is highly
> expensive (at times they can cost you significantly more than cost of
> instance).
>
> But they have ephemeral local storage and data is lost once instance is
> stopped, you need to be prudent in case of i series, it is generally used
> for large persistent caches.
>
>
>
> Regards,
>
> Bhuvan
>
> On Tue, May 23, 2017 at 4:55 AM, Gopal, Dhruva <Dhruva.Gopal@aspect.com>
> wrote:
>
> Hi –
>
>   We’ve been running M4.2xlarge EC2 instances with 2-3 TB of storage and
> have been comparing this to I-3.2xlarge, which seems more cost effective
> when dealing with this amount of storage and from an IOPS perspective. Does
> anyone have any recommendations/ on the I-3s and how it performs overall,
> compared to the M4 equivalent? On the surface, without us having taken it
> through its paces performance-wise, it does seem to be pretty powerful. We
> just ran through an exercise with a RAIDed 200 TB volume (as opposed to a
> non RAIDed 3 TB volume) and were seeing a 20-30% improvement with the
> RAIDed setup, on a 6 node Cassandra ring. Just looking for any
> feedback/experience folks may have had with the I-3s.
>
>
>
> Regards,
>
> *DHRUVA GOPAL*
>
> *sr. MANAGER, ENGINEERING*
>
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>
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>
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>
> *dhruva.gopal@aspect.com <dhruva.gopal@aspect.com> *
>
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