5 ms·
As others have pointed out, measuring latency from an AWS Lambda function to a co-located single node in-memory non-durable key-value database (Redis), or to a
by evanweaver 5y ago
As others have pointed out, measuring latency from an AWS Lambda function to a co-located single node in-memory non-durable key-value database (Redis), or to a co-located single AZ eventually consistent key-value database (DynamoDB), doesn't have anything to do with measuring client-observed latency from the browser to a globally distributed ACID-compliant document database.
A similar process co-located with a Fauna region normally can also perform simple reads in small numbers of milliseconds.
Similarly, a browser client querying a lambda function multiple times from the other side of the world will also be quite slow, even if the lambda "thinks" its queries are fast because its database is right next to it.
It is not completely clear to me what else is going wrong, but the basic premise of the benchmark is invalid, and there are other errors in regard to Fauna. For example, index serializability only affects write throughput; it has nothing to do with read latency. The status page reports write latency, not read latency, etc.
For a more even-handed comparison of Fauna to DynamoDB, see this blog post: https://fauna.com/blog/comparing-fauna-and-dynamodb-pricing-features https://fauna.com/blog/comparing-fauna-and-dynamodb-pricing-...
- mfateev 5y agoAWS DynamoDB is multi-AZ and is strongly consistent (at least for a single key update). I believe you confused it with a Dynamo DB described in a paper Amazon published long ago. AWS DynamoDB has nothing to do with a eventually consistent design the paper describes. It was purely marketing gimmick to call the new AWS Service that.
- evanweaver 5y agoPlease read the blog post: https://fauna.com/blog/comparing-fauna-and-dynamodb-pricing-features https://fauna.com/blog/comparing-fauna-and-dynamodb-pricing-...
- k__ 5y agoGood article, thanks. I'm currently reading The DynamoDB Book, and even it's author acknowledges that DynamoDB is serverless more as a byproduct and shouldn't be used for that reason alone But as a product developer all these highly integrated AWS services that can be provisioned with CloudFormation are pretty convincing. What's Fauna's IaC story?
- noahfschr 5y agoI will be happy if someone from Fauna team helps me to improve my code. https://github.com/upstash/latency-comparison https://github.com/upstash/latency-comparison Upstash is not non-durable. It is based on multitier storage (memory + EBS) implementing Redis API. In a few weeks, I will add upstash premium which replicates data to multiple zones, to the benchmark app. In the blog post, I mentioned the qualities where Fauna is stronger than the others: https://blog.upstash.com/latency-comparison#why-is-faunadb-slow-in-this-benchmark https://blog.upstash.com/latency-comparison#why-is-faunadb-s...
- evanweaver 5y agoYour own docs say that by default “writes are not guaranteed to be durable even if the client receives a success response”.
- noahfschr 5y agoUpstash has two consistency modes. Eventual consistency and Strong consistency. Please see: https://docs.upstash.com/overall/consistency https://docs.upstash.com/overall/consistency In my code, Upstash database was eventually consistent. Similarly the index in the FaunaDB was not serialized. But both of those should not affect the latency numbers in the histogram because those numbers are all read latency.
- rbranson 5y agoThat's an apples to oranges comparison though. Upstash couples durability with consistency/isolation. Regardless of configuration, FaunaDB and DynamoDB both always ensure durability of acknowledged writes with a fault tolerance of greater than 1 node failure. To compare them on equal footing, Upstash would need to be configured for strong consistency, at least according to the docs.
- ec109685 5y agoDynamoDB also guarantees your write is distributed to multiple data centers as well.
- Aeolun 5y ago> For a more even-handed comparison of Fauna to DynamoDB, see this blog post: https://fauna.com/blog/comparing-fauna-and-dynamodb-pricing- https://fauna.com/blog/comparing-fauna-and-dynamodb-pricing-... An even handed comparison from the authors of FaunaDB?
- pier25 5y agoI found that comparison to be technically objective. Did you find some bias on it?
- maximilianroos 5y agoWhile your points are valid, that you're CTO of Fauna is relevant information.
- fierro 5y agonot really. these are all facts, not opinions.
- ec109685 5y agoIf people really want to know how DynamoDB works, this is a good tech talk: https://www.youtube.com/watch?v=yvBR71D0nAQ https://www.youtube.com/watch?v=yvBR71D0nAQ
- evanweaver 5y agoI think we figured out at least one issue here. Fauna is a temporal database, not a time series database. The code in the test that updates the score on every post after every read is creating new historical events every time it does that. These have to be read and skipped over during the read query which will continually increase latency proportional to the number of updates that have occurred. By default, Fauna retains this data and makes it queryable (with transactional guarantees) for 30 days, unlike DynamoDB or Redis. Reducing the retention period would help a bit, but event garbage collection is not immediate so there will still be differences for heavily churned documents. Normally, having a few updates to a document or an index has no noticeable impact but in this case it appears to be swamping the other factors in the latency profile. It is possible to manually remove the previous events in the update query; doing that should reduce the latency. Nevertheless, Fauna is not a time series database so this is a bit of an anti-pattern.
- noahfschr 5y agoI have commented this section and redeployed the code. See the Fauna endpoint: https://71q1jyiise.execute-api.us-west-1.amazonaws.com/dev/fauna https://71q1jyiise.execute-api.us-west-1.amazonaws.com/dev/f... See the code: https://github.com/upstash/latency-comparison/blob/master/newsapis/faunaHandler.js https://github.com/upstash/latency-comparison/blob/master/ne...
- evanweaver 5y agoDid you delete all the extra events that have been created already?
- deleted 5y ago[deleted]
- noahfschr 5y agoIf you mean histogram, yes I reset the histogram for Fauna. If you mean deleting Faunadb internal events, I do not know how to do. Can you guide me?
- deleted 5y ago[deleted]
- ec109685 5y ago“Writes always go through a leader replica first; reads can come from any replica in eventually-consistent mode, or the leader replica in strongly consistent mode.” This part isn’t correct. The two follower replicas can serve a consistent read even if the leader is behind / down. And there is no guarantee the primary even has the data persisted to disk when the subsequent read call is made.