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From Brian Tarbox <>
Subject best practices on EC2 question
Date Thu, 16 May 2013 14:05:40 GMT
>From this list and the NYC* conference it seems that the consensus
configuration of C* on EC2 is to put the data on an ephemeral drive and
then periodically back it the drive to S3...relying on C*'s inherent fault
tolerance to deal with any data loss.

Fine, and we're doing this...but we find that transfer rates from S3 back
to a rebooted server instance are *very * 15 MB/second or
roughly a minute per gigabyte.  Calling EC2 support resulting in them
saying "sorry, that's how it is".

I'm wondering if anyone a) has found a faster way to transfer to S3, or b)
do people skip backups altogether except for huge outages and just let
rebooted server instances come up empty to repopulate via C*?

An alternative that we had explored for a while was to do a two stage
1) copy a C* snapshot from the ephemeral drive to an EBS drive
2) do an EBS snapshot to S3.

The idea being that EBS is quite reliable, S3 is still the emergency backup
and copying back from EBS to ephemeral is likely much faster than the 15
MB/sec we get from S3.



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