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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 avo

by gruseom 16y ago

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?

snorkel 16y ago
Using EBS has other features that are hard to overlook, such as snapshots and ability to quickly move your volumes to another instance when an instance failure happens, or if you needed to change the size of an instance (which you couldn't do directly until very recently).
krakensden 16y ago
All of your EC2 instances can disappear without warning and everything on the local storage is now gone forever.
- gruseom 16y ago
  That's the "backup to S3" part.
  - krakensden 16y ago
    That's a fair point, but I don't think it holds up real well. What are the semantics? Do you block until everything is fully backed up on S3? Are you continuously taking database snapshots and forwarding them to S3? What happens if the backups start to fall further and further behind production? What do you tell the hordes of angry redditors when the last thirty minutes of carefully (or angrily) composed comments vanish?
cachemoney 16y ago
EBS-RAID0 is much faster for reads than local. Local is faster for writes.
- riledhel 16y ago
  this seems to contradict several comments here. "citation needed".
  - cachemoney 16y ago
    I run a database cluster with dozens of nodes on EC2. Small entries, lots of small IOPS. From http://orion.heroku.com/past/2009/7/29/io_performance_on_ebs/ http://orion.heroku.com/past/2009/7/29/io_performance_on_ebs..., "On a good day, an EBS can give you 7,000 seeks per second and on a not so good day will give you only 200." The ephemeral store will never give you more than a hundred seeks per second. If you're seek-bound, then EBS, every time.
  - bmurphy 16y ago
    My experience has been that EBS handles concurrent loads better, ephemeral drives handle non-concurrent loads better. Transferring 100gb+ of data on EBS (even with an 8x RAID) is a nightmare. Ephemeral drives, however, it's fairly fast. Throw 100+ database connections at a few ephemeral drives (even in a RAID) and watch your web site slow to a crawl.

by gruseom 16y ago

snorkel 16y ago

Using EBS has other features that are hard to overlook, such as snapshots and ability to quickly move your volumes to another instance when an instance failure happens, or if you needed to change the size of an instance (which you couldn't do directly until very recently).

krakensden 16y ago

All of your EC2 instances can disappear without warning and everything on the local storage is now gone forever.

gruseom 16y ago
That's the "backup to S3" part.
- krakensden 16y ago
  That's a fair point, but I don't think it holds up real well. What are the semantics? Do you block until everything is fully backed up on S3? Are you continuously taking database snapshots and forwarding them to S3? What happens if the backups start to fall further and further behind production? What do you tell the hordes of angry redditors when the last thirty minutes of carefully (or angrily) composed comments vanish?

cachemoney 16y ago

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

riledhel 16y ago
this seems to contradict several comments here. "citation needed".
- cachemoney 16y ago
  I run a database cluster with dozens of nodes on EC2. Small entries, lots of small IOPS. From http://orion.heroku.com/past/2009/7/29/io_performance_on_ebs/ http://orion.heroku.com/past/2009/7/29/io_performance_on_ebs..., "On a good day, an EBS can give you 7,000 seeks per second and on a not so good day will give you only 200." The ephemeral store will never give you more than a hundred seeks per second. If you're seek-bound, then EBS, every time.
- bmurphy 16y ago
  My experience has been that EBS handles concurrent loads better, ephemeral drives handle non-concurrent loads better. Transferring 100gb+ of data on EBS (even with an 8x RAID) is a nightmare. Ephemeral drives, however, it's fairly fast. Throw 100+ database connections at a few ephemeral drives (even in a RAID) and watch your web site slow to a crawl.