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0 pointsacdha14y ago0 comments

> As far as I remember, previous failure which happen with Amazon earlier this year have also affected Multi-AZ deployments too.

Which failure? The networking issue which had nothing to do with RDS and left your data unaffected?

> Anyway, I don't think that we are ready to invest large amount of money on Multi-AZ deployments to the doubtful reliability. Cloud solutions even with single AZ should not loss data.

Any server can go down. The very modest increase for a multi-AZ setup buys you real, meaningful improvements as you just learned. I'm sorry that you had to learn a lesson the hard way but there's a reason why AWS recommends a multi-AZ deployment for failover and it's not revenue.

The next step up would require you having multiple widely separated servers, which is where you really start talking about large amounts of money because you're talking about non-trivial engineering and taking on the operational overhead of 24x7 support.

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4 comments · 1 top-level

akhkharu14y ago· 3 in thread

Yes, networking issue which brought down even multi-az deployments.

I don't want to setup highly available fault tolerant systems, I just want a good level of reliability of a service provider. Probably, we will migrate to the dedicated servers out of Amazon soon. It will be harder to maintain, but cheaper and, as practice shows, more reliable.

ceejayoz14y ago

"Brought down" and "Brought down and lost data" are very different severities. Many businesses can handle occasional downtime as long as data's not disappearing into the ether.

acdhaOP14y ago

> Yes, networking issue which brought down even multi-az deployments.

You might want to learn more about this before making business decisions on it. RDS was completely unaffected, as were all of my EC2 servers. They didn't receive any traffic from the internet but the systems were running fine throughout the brief outage interval.

A quick Google search will reveal that this is not uncommon for any hosting setup - data centers have lost network connections, routers can fail or be misconfigured, etc. - which is why anyone with serious uptime requirements has multiple widely separated data centers. Using AWS doesn't magically remove the need to avoid single points of failure in your system design.

> Probably, we will migrate to the dedicated servers out of Amazon soon. It will be harder to maintain, but cheaper and, as practice shows, more reliable.

I hope you have a good ops team and extra engineering resources; otherwise you'll learn very quickly that dedicated servers have the same failure modes. So far we're at ~18 minutes of AWS downtime this year - that's not going to be easy to beat.

superuser214y ago

>It will be harder to maintain, but cheaper and, as practice shows, more reliable.

Practice shows that Amazon's uptime isn't perfect. Where's the evidence that a dedicated server is?

(There may well be evidence to support that. But I get awfully weary of the "it's not cloud so it must be more reliable" trap.)

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