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Comment by biggestdummy | Hacker News Reader

Are you serious? Or is my sarcasm meter faulty?

So you solve 500 errors by provisioning 4x your usage? Seems like solving a leak in the gas tank by instructing the user to simply fill up the tank more often.

Nice business if you are the gas station!

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> Are you serious?

They really are. In order to make effective (let alone efficient) use of DynamoDB you need to keep in mind exactly how it works behind-the-scenes and exactly how the charging models works at all times. And you have very few, very coarse levers to pull (over-provision, under-provision, etc.)

Every in-depth explanation or tutorial of DynamoDB I've seen advises to do things like this in multiple different load scenarios. There's a pretty good intro for DynamoDB over at acloud.guru: https://acloud.guru/learn/aws-dynamodb - beware though, it costs money and it's very long (though it's split up so you can cherry pick the bits you care about).

I think DynamoDB might be worth investigating when you're hitting a scale where most other off-the-shelf options don't work and you'd be heading down the path of building your own solution on top of something anyway.

I'd just point out Scylla tries to auto-tune itself, so you don't need to know about or perform such dark arcana just to get it working out-of-the-box. I mean, I get it. Databases are hard. But this is a hidden gotcha that you should not have to pay through the nose (in time or money) to learn to avoid.

When you are hitting a real scale, DynamoDB becomes prohibitively expensive.

What was your own experience like?

We run a lot on aws. Services, databases, ... Cassandra, Aerosoike, Couchbase, DynamoDB to name a few. Each of them is good in something, but DynamoDB is the most expensive one. For small datasets with low RPS it provides a lot of value, but once you scale, it becomes cheaper to run ouselves (even including licensing costs). I blame their linear pricing model.

Thanks for the feedback, LaserToy!

This is a kludgy way to get DynamoDB to leave your table split across more shards, even after you dial it down to the capacity you need.

It may work at the price of 4x which is already 7x higher, resulting in 28x total.. not to mention the hassle. Man, give us a try.

Seen your comment about LWT, agree.. We knownly chose the first make MV/SI great before committing to another big feature. Glad to say that with Scylla 3.0 release this month we'll finally get LWT done

It's a price of 4x higher for just long enough to create the table, not for the duration of the test.

The suggestion was to provision it at 4x, then dial back down to 1x, then load the data. This is to force DynamoDB to split the partitions further before you use them so that they don't split while you're filling the table.

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