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"Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

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Re: "Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

#91

Post by gregburek »

joevandyk wrote: post #46
mithaler wrote: post #10

We were bitten by EBS' slowness at my company recently, when moving an existing project to AWS. You effectively can't get decent performance off of a single EBS volume with PostgreSQL; you need to set up 10 or so of them and make a software RAID to remove the bottleneck. It's a fairly large time commitment to build and maintain, but it's pretty fast and reliable once it's up and running (cases like the recent downtim…

Did you use Raid10? I would love to see a post on using postgresql with ec2/ebs -- how to setup raid, etc.

Build-out Script for Postgres/PostGIS with RAID 10 on Amazon EBS volumes: http://sproke.blogspot.com/2010/12/build-out-script-for-post...

Re: "Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

#92

Post by danielrhodes »

What's the failure rate of EBS versus having direct access to physical disks? My guess is that at scale, it's probably similar.

Although you would hope that the storage components of AWS's cloud were highly reliable, I think the main benefit is not single instance reliability but being able to recover faster because of quickly available hardware.

Re: "Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

#93

Post by krobertson »

watchandwait wrote: post #59
snorkel wrote: post #43

Having been at a startup that used hundreds of EC2 instances and EBS volumes I can assure you all that Amazon EBS performance is downright terrible and Amazon didn't inspire any confidence that they could solve it. Even worse than the EBS performance is Amazon does not offer any shared storage solutions between EC2 instances. You have to cobble together your own shared storage using NFS and EBS volumes making it suck…

My experience with the AWS RDS database product has been excellent.

We looked at RDS and had a call with some of their engineers, but we basically had our EC2 + raid'd EBS set up almost the same as they did, all best practices already being done.

Since RDS really is EC2 + EBS, they couldn't provide any real assurances it performed better than our own installation.

We ended up moving off of AWS as a whole. After several discussions about how we can continue to scale, the ultimate answer was without AWS.

EC2 is great for distributed stuff, but when need something that is heavy IO, for instance, it is a big problem. Scaling it ends up costing more to work around AWS's performance problems than to go elsewhere.

Re: "Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

#94

Post by powertower »

jedsmith wrote: post #30
ck2 wrote: post #24

I firmly believe "the cloud" is a fad, unless for some reason you own and operate all the hardware yourself (ie. Google). Like other technical fads, everyone will probably come back to servers they can reach out and touch when needed, sooner or later.

The cloud significantly lowers capital expenditure to get into an Internet-enabled business, which cultivates the very startup ecology that Y Combinator exists to leverage and support. Those teenagers who started the Facebook Pokemon game would have never had the resources to build a scalable solution with hardware that they own. (That is, unless Y Combinator paid a lot more money as part of participating. They might…

Cloud = Marketing(VPS);

Re: "Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

#95

Post by Duff »

ck2 wrote: post #24

I firmly believe "the cloud" is a fad, unless for some reason you own and operate all the hardware yourself (ie. Google). Like other technical fads, everyone will probably come back to servers they can reach out and touch when needed, sooner or later.

It's not a fad, it's shared services. Sharing comes at the cost of flexibility, which can be a pain in the butt.

Personally, if I'm going to be operating a large computing environment, I'd rather stick 80% of my workload in a cloud environment and pay someone to deal with utilities, buildings, hardware, etc.

The remaining 20% may require a "higher touch" setup at a colo or a facility that I control. The smaller I can make that 20%, the less I need to spend on setting up and maintaining infrastructure.

Re: "Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

#96

Post by ketralnis »

krobertson wrote: post #93
watchandwait wrote: post #59

Earlier quoted context omitted.

My experience with the AWS RDS database product has been excellent.

We looked at RDS and had a call with some of their engineers, but we basically had our EC2 + raid'd EBS set up almost the same as they did, all best practices already being done. Since RDS really is EC2 + EBS, they couldn't provide any real assurances it performed better than our own installation. We ended up moving off of AWS as a whole. After several discussions about how we can continue to scale, the ultimate answ…

Yeah they have a few products (e.g. EMR, RDS) where they charge by the instance anyway so you're just paying them by the hour for the five minutes it would take you to set up the server once

Re: "Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

#97

Post by riledhel »

cachemoney wrote: post #84
gruseom wrote: post #56

Anybody care to comment on using EC2 with local (what Amazon calls ephemeral) storage and backup to S3? Seems to me the advantages are: it's cheaper and you avoid the performance and reliability problems with EBS. The disadvantages?

EBS-RAID0 is much faster for reads than local. Local is faster for writes.

this seems to contradict several comments here. "citation needed".

Re: "Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

#98

Post by macros »

ceejayoz wrote: post #74
WALoeIII wrote: post #69

Earlier quoted context omitted.

You can't do multi-master with MySQL anyways, which until very recently has been the only "engine" RDS supports. Even if you could do multi-master, replication is still single threaded. You have to come up with your own sharding scheme. This is a limitation of MySQL not RDS.

You can't do multi-master with MySQL? News to me - we've been using circular replication between two servers, each a master and slave, for quite some time now. Not possible with RDS, unfortunately, but works fine on two EC2 instances.

You can do it, but it won't scale your write load. In most cases it actually makes it worse due to the having to apply all the writes taken on the other master node in serial.

Re: "Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

#99

Post by bmurphy »

xpaulbettsx wrote: post #51
bluegene wrote: post #35

Earlier quoted context omitted.

May be I'm missing something here; Why there's even a discussion about RAID at the EBS level? When Amamzon says, "Amazon EBS volumes are designed to be highly available and reliable" and if we have to talk about RAID then the issue is on Amazon's end

I think most people are doing RAID-0 to get more perf out of EBS volumes

Yes. Except, anybody who is doing RAID-0 over an EBS volume for perf reasons is ASKING for trouble.

You need to do RAID-10. EBS volumes CAN and DO fail.

Re: "Amazon's EBSs are a barrel of laughs in terms of performance and reliability"

#100

Post by bmurphy »

saurik wrote: post #54
mithaler wrote: post #10

We were bitten by EBS' slowness at my company recently, when moving an existing project to AWS. You effectively can't get decent performance off of a single EBS volume with PostgreSQL; you need to set up 10 or so of them and make a software RAID to remove the bottleneck. It's a fairly large time commitment to build and maintain, but it's pretty fast and reliable once it's up and running (cases like the recent downtim…

Did you do any performance tweaking to PostgreSQL with respect to EBS? You have an insanely deep write buffer and quite good random read performance with EBS, which is nothing like the disks people normally deploy PostgreSQL to.

I tuned the hell out of our big postgresql instance a year ago, but I'll be damned if I can remember the rational for every change. I have a list of all the changes from default, but I've long since forgotten/lost the reason for making them.

That being said, we get more bang for our buck by spreading our data across many small databases that don't need much tuning beyond upping the memory defaults. The EC2 cloud isn't great for the uber-server, but it's halfway decent for many small servers.

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