Amazon ElastiCache - Now With a Dash of Redis

Based on personal experience, I found that paying for the setup, tuning and 24/7 maintenance of a dedicated is way more expensive than using those service.

But I'm one of those crazy people who considers their time and that worth something.

Excuse the snark, but these arguments just keep repeating themselves. There's a reason they're called "services". It's like saying "it's cheaper to slaughter your own cow than to eat at a restaurant".

This is true only if your time is free or you're cutting corners on reliability. For example, using an EC2 medium instance on-demand is $0.120/hour and RDS is $0.160/hour. If you use enough MySQL, that $0.04/hour (in reality, $0.022 at reserved rates) can reach the point where it's worth rolling your own management stack, backups, failover, etc. but there are many people who will never reach the point where they don't have higher-priority investments to make.

+1 for Mongodb on a EC2 instance instead of Dynamodb

We're transitioning off Dynamo as soon as possible as the billing structure makes it either a real headache or very expensive.

For example: if you want to make a backup of a large table or move data around, it'll either take days or cost you an arm and a leg. This is just one of many annoyances. Ever since making the decision to go with Dynamo over Mongo, I've been getting dirty looks from my team.

Two things:

1. What kind of EC2 instance are we talking about for MongoDB? If you're not using an SSD, comparing Dynamo and Mongo wouldn't be an apples-to-apples comparison.

2. I buy that the strictly technical costs of these systems is lower, but I'm not certain I buy that the overall cost (including engineer time to set these services up and monitor them) is lower.

If you have the staff, I definitely can see this. For a small team (in my case, 2) RDS was a no brainer. More than anything, letting Amazon handle backups was a big win. However, in a use case where you need more control (I realize you can ssh/rdp in, but there are limited configuration options) or more performance (the highest performing instance types aren't available) or flexibility (for SQL Server, you can't perform the full range of import, etc activities due to permissions), RDS may not be the best fit.

I think you wanted to say "on an EC2 machine", instead of "dedicated machine". Otherwise, people might think you're referring to physical hardware.

At scale this is probably cheaper, if your a startup trying to scale, probably not.

why even use EC2 then? It would be much cheaper to use any other hosting provider.

Exactly. This is especially important when using it in conjunction with Heroku.

Well unless you roll with a Micro instance (213mb of RAM and dismal performance), the price for a Small on-demand instance (1.3GB memory) is ~$54 per month. You save quite a bit by going with a reserved instance, where you pay about $70 up-front but then your monthly instance price is almost halved, coming in at around $32 per/mo.

Either way, it's going to be more cost-effective at a lower level to go with something like Redis-to-go, Openredis, etc... if you need something simple.

Long story short, if you're on Heroku and (like me) were thinking/hoping that this might be a nice alternative to the various add-ons available ... I don't think that the juice is worth the squeeze. One, you have to administer and maintain things yourself (which is trivial for something like this, so not a big deal) but the pricing doesn't line up. The Redis providers leading the market today are able to do so because they provision the heavy-hitter EC2 nodes and then chop them up.

It's important to note though you can get a free micro instance for a year on the free usage tier. Micro's are like the section-8 housing of the server world, but free is free and beggars can't be choosers ;)

I think the main benefit would be for people already running on EC2/AWS. I would imagine (but don't know) that you'd get better latency and throughput between an EC2 instance an elasticache instance than between an EC2 instance and a hosted redis provider.

Also worth pointing out: if you're running on AWS, you'd get integration with your existing tooling like CloudWatch, VPCs, etc.

And last but not least, Amazon is a mature company that you can be confident will be around another 5 years. I don't have that same level of confidence with the majority of Redis-as-a-service providers.

Compared to normal Redis-Paas, it's on the same line, probably cheaper than the average price on ther market. ElastiCache is basically a way to spin up a EC2-backed instance of Redis, with automatic failover and replication. It only handles one node per cluster, and doesn't handle scaling (you need to manual provision, replicate, switch, etc.).

But if you go with a true clustering solution (like Redis Cloud, www.redis-cloud.com), then you get automatic transparent scaling with zero downtime thanks to dynamic sharding:

http://redis-cloud.com/redis/redis-comparison

To me, such a cluster solution justifies the PaaS price over a manual Redis installation.

I can't tell if you're joking - it's meant precisely for people whose "data center" IS AWS, for exactly the reason you gave.

If you're using other AWS services, then this makes a lot of sense. It saves you the hassle of setting multiple redis nodes on EC2 and the (admittedly low) maintenance.

I think it's a good move on their part.

They handle automatic failover, which redis does not currently do out of the box. That part is pretty cool. Maybe not worth the price, but definitely useful.

We just spent days moving stuff away from Elasticache due to memcached limitations, and would love to have moved to managed Redis. We're an AWS partner, with the highest level support contract and if we'd known two weeks ago that this was in the pipeline, we would have waited. AWS, why don't you give us any road map for stuff like this?