

Fast Forward - Provisioned IOPS for EBS Volumes - jeffbarr
http://aws.typepad.com/aws/2012/08/fast-forward-provisioned-iops-ebs.html

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Smerity
From the previous company I worked at (which used AWS infrastructure
exclusively) and many others I've spoken to, IOPS were the leading issue when
it came to AWS usage. Many insane solutions were proposed (such as RAID across
multiple EBS just to maintain consistent disk performance), but for most use
cases the only guaranteed solution was to move everything to RAM and assume
disk is either stunted or useless.

My guess is that in the coming weeks, the infrastructure of the companies I
spoke to will change substantially. The SSD instances are now the goto
solution if you have a server up 24/7 and (Provisioned IOPS / EBS-Optimized
instances) are for when you need burst infrastructure with good disk
performance.

There are gaps in the AWS armour, but those gaps have been filled in at a
consistent rate.

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abrookewood
I don't understand why you think utilising RAID across EBS volumes is insane.
For years, if people needed more IOPs than a single drive could deliver, they
utilised RAID to acheive it. How is this any different?

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cagenut
Because EBS has astonishing variance in its response times that cause the
entire raidset to have very inconsistent performance. Numbers here:
[http://www.mysqlperformanceblog.com/2011/02/21/death-
match-e...](http://www.mysqlperformanceblog.com/2011/02/21/death-match-ebs-
versus-ssd-price-performance-and-qos/)

In order for raid-on-ebs to truly perform well you have to setup per-volume
monitoring that ejects volumes from the raidset (and runs in degraded mode)
when they start performing 10x worse, and then rebuilds the back on to it (or
a new one) later. It becomes a rather arcane wizard work contraption of on-
the-fly raid config changes, which IMHO qualifies as "insane".

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blo
Pure cost comparison:

Let's ignore the $0.10/GB-month vs. $0.125/GB-month storage pricing as it is
negligible compared to IOP costs.

Standard EBS volumes average 100 IOPS with best effort bursting.

A provisioned EBS volume at 100 IOPS would cost $0.10/IOPS-month * 100 IOPS =
$10/month

A standard EBS volume cost would be $0.10/1000000 IOP (an equivalent of
$0.26/IOPS-month). The breakeven with the provisioned EBS occurs at 38%
utilization (38 IOPS), meaning that provisioned EBS is cheaper above this
point.

To match the performance of a 4 volume standard EBS RAID (400 IOPS), you would
have a minimum fixed cost of $40/month/GB, vs. the current $0.40/month/4GB +
variable IOP pricing.

Provisioned EBS makes sense for scenarios with sustained high IOPS utilization
as you get consistent performance with possible lower total costs. For less
IO-intensive loads, using a RAID of standard volumes will be more cost-
effective.

~~~
jswanson
The way they calculate it is a little misleading.

From AWS[1]: Provisioned IOPS is charged by the amount you provision in IOPS
(input/output operations per second) X the amount of days you provision for
the month.

If I understand the above correctly, the estimate of $10/month would actually
be:

$0.10 * 30 days * 100 IOPS = $300/month (In USEAST)

[1] <http://aws.amazon.com/ebs/>

~~~
cperciva
_the amount of days_

They've fixed that, it now says "the percentage of days".

~~~
jswanson
Thank you for pointing that out, and kudos to Amazon for updating their doc.
They have an easy to understand sample calculation up now as well.

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bradgessler
Can't wait for RDS to plug into this.

~~~
jaredstenquist
I also wish they announced when RDS might start running off of these. In order
to achieve higher IOPS i've provisioned 350GB of disk for my ~50GB database. I
came across a rumor that after 300GB of space, AWS enables striping and
figured it was worth the marginal extra cost.

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jl6
$0.10 per IOPS-month? Is that per volume or does volume size enter into the
equation? I.e. would two 10GB 100IOPS volumes cost twice as much as one 20GB
100IOPS volume?

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count
I would assume it's per-volume as 2 10GB 100IOPS volumes would be 200 IOPS,
while a single 20GB volume would only be 100 IOPS.

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mschalle
Hopefully this shuts up people always complaining about EBS...

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elq
As someone whose team used the beta of this product - No.

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bermanoid
As in no, you didn't consistently get within 10% of the IOPS you provisioned
at their promised 99.9%? Or were there other problems?

I'd be pretty surprised if they were going live with this without being able
to deliver, especially since this is likely to be _very_ popular with people
using EBS for databases under fairly consistent loads. It's one thing for I/O
to suck when they're not actually promising anything, but it's quite another
when you're very specifically paying for a performance guarantee...

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quattrofan
2012 and unviewable on my mobile sad face

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jordanthoms
Strange, it works fine in chrome for Android.

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quattrofan
Ah I should've tried that, good tip.

