Re: Reliability with RAID 10 SSD and Streaming Replication

On 5/16/13 7:52 PM, Cuong Hoang wrote:
> The standby host will be disk-based so it
> will be less vulnerable to power loss.

If it can keep up with replay from the faster master, that sounds like a
decent backup. Make sure you setup all write caches very carefully on
that system, because it's going to be your best hope to come back up
quickly after a real crash.

Any vendor that pushes Samsung 840 drives for database use should be
ashamed of themselves. Those drives are turning into the new
incarnation of what we saw with the Intel X25-E/X-25-M: they're very
popular, but any system built with them will corrupt itself on the first
failure. I expect to see a new spike in people needing data recovery
help after losing their Samsung 840 based servers start soon.

> I forgot to mention that we'll set up Wal-e
> <https://github.com/wal-e/wal-e> to ship base backups and WALs to Amazon
> S3 continuous as another safety measure. Again, the lost of a few WALs
> would not be a big issue for us.

That's a useful plan. Just make sure you ship new base backups fairly
often. If you have to fall back to that copy of the data, you'll need
to replay anything that's happened since the last base backup happened.
That can easily result in a week of downtime if you're only shipping
backups once per month, for example.

--
Greg Smith 2ndQuadrant US greg(at)2ndQuadrant(dot)com Baltimore, MD
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