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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"

#81

Post by btucker »

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.

Anything more you could share about it? We got scared off (at least for now) by the inability to replicate in from a self-hosted MySQL instance (for migration purposes), but would still love to hear more about your experiences.

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

#82

Post by Zak »

saurik wrote: post #50
Zak wrote: post #39

I recently had an EBS volume lose data for no apparent reason. I'm not a heavy EC2 user at all - I was just doing some memory/cpu-heavy stuff that wouldn't fit in to RAM on my laptop and using EBS as a temporary store so I could transfer data using a cheap micro instance and only spin up the big expensive instances when everything was in place. I ended up downloading files on an m2.4xlarge because the files I had jus…

Are you certain the data left the filesystem buffer and actually got acknowledged by EBS?

No; I'm very much a beginner when it comes to EC2. I unmounted the filesystem, detached the volume, then shut down the instance.

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

#83

Post by icey »

tzs wrote: post #73

We've been looking at moving some or all of our stuff to either Amazon EC2/EBS/S3 or Rackspace cloud hosting, and it has been interesting. Amazon seems more flexible, since you buy block storage (EBS) independent of instances. If you have an application that needs a massive amount of data, but only a little RAM and CPU, you can do it. Rackspace, on the other hand, ties storage to instances. If you only need the RAM a…

I use the Rackspace cloud for a few Windows servers. The experience has been mostly positive, but they disappear for a few minutes each week, which is kind of troubling.

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

#84

Post by cachemoney »

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.

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

#85

Post by grourk »

joevandyk wrote: post #64
grourk wrote: post #53

Earlier quoted context omitted.

Orion Henry at Heroku wrote about this and described different software RAID configurations and the performance characteristics of each a while back: http://orion.heroku.com/past/2009/7/29/io_performance_on_ebs...

Yes, but as a lowly developer, I have no idea how to set read-ahead buffers or change io schedulers. Plus, that's a year old, would love to see some updated advice. You'd think Amazon would write more guides like this.

Well, that's really just "-setra" and other file system mounting options, and mdadm (Linux software RAID) configuration options. Yes, there's a little bit of a learning curve and pain to get things set up, but it's not completely out of reach.

Despite being relatively old, I think the advice and approach still holds. Clearly, EBS hasn't improved since then and the need to do this kind of striping over EBS volumes hasn't been obviated yet.

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

#86

Post by bmurphy »

Having been running a 200gb millions of transactions per day Postgres cluster on Amazon's EC2 cloud for two years now, I can attest to the fact that EBS performance and reliability SUCKS. It is our SINGLE biggest problem with EC2.

200gb really isn't all that big of a database. It shouldn't have to be this hard.

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

#87

Post by gregburek »

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

It also seems that in 2008 adding mirroring also hurt performance. I'm going to dive into this tonight to see if things have changed at all with these benchmarks.

"His results show a single drive maxing out at just under 65MB/s, RAID 0 hitting the ceiling at 110MB/s, RAID 5 maxxing out about 60MB/s, and RAID 10 “F2″ at under 55MB/s."

Summary source: http://www.nevdull.com/2008/08/24/why-raid-10-doesnt-help-on...

Data source (google cache): http://webcache.googleusercontent.com/search?q=cache:Vscz-VX...

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

#88

Post by danielrhodes »

absconditus wrote: post #41

How is it that Amazon.com is so reliable if there are so many problems with their "cloud" products? Do they not use the same software to run their site?

Amazon.com is not hosted on EC2. It's entirely separate.

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

#89

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.

I found a benchmark from 2008 that details the problems with RAID10 and sourced it in a comment above [1]. These are just raw disk transfer numbers, though. I can only imagine how they would change as CPU usage/postgres load climbs. IIRC disk IO is network traffic and network traffic is CPU dependent, so as load increases, IO will suffer greatly.

[1] http://news.ycombinator.com/item?id=2341425

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

#90

Post by delano »

tzs wrote: post #73

We've been looking at moving some or all of our stuff to either Amazon EC2/EBS/S3 or Rackspace cloud hosting, and it has been interesting. Amazon seems more flexible, since you buy block storage (EBS) independent of instances. If you have an application that needs a massive amount of data, but only a little RAM and CPU, you can do it. Rackspace, on the other hand, ties storage to instances. If you only need the RAM a…

If you're interested to see how sites perform on EC2 and Rackspace over time:

https://www.blamestella.com/vendor/ec2

https://www.blamestella.com/vendor/rackspace

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