Apple open-sources FoundationDB • Hacker News Board

Re: Apple open-sources FoundationDB

#51

Post by djtriptych » Thu, Apr 19, 2018, 5:33 PM UTC

I went to the same high school as the founders[1]. They were about the 2 best software engineers in a school with a LOT of very smart software engineers. Another pair founded Yext, which went public last year. I still consider that school the group with the highest concentration of raw brain power I've ever been a part of.

I'm probably a 1% engineer, been hired by M$, FB, and Google. These guys were light years ahead of me. I'm not sure I'm as good now as they were at like 17 years old. In fact I'm probably only a decent engineer from having observed the stuff they were doing back then and finding inspiration.

1: https://en.wikipedia.org/wiki/Thomas_Jefferson_High_School_f...

Re: Apple open-sources FoundationDB

#52

Post by nlavezzo » Thu, Apr 19, 2018, 5:33 PM UTC

misterbowfinger wrote: post #43

I hate to be that person, but when I hear "ACID transactions in a distributed database", I hear Citus/Spanner/CockroachDB. I'm positive that Citus & Spanner are quite different from FoundationDB, but I have no idea how. Googling didn't help much. Can someone provide an overview of the differences?

Well for one, Spanner is not available except as a service.

Re: Apple open-sources FoundationDB

#53

Post by thefounder » Thu, Apr 19, 2018, 5:34 PM UTC

wwilson wrote: post #2

This is INCREDIBLE news! FoundationDB is the greatest piece of software I’ve ever worked on or used, and an amazing primitive for anybody who’s building distributed systems. The short version is that FDB is a massively scalable and fast transactional distributed database with some of the best testing and fault-tolerance on earth[1]. It’s in widespread production use at Apple and several other major companies. But the…

I'm not familiar with FDB but what you say sounds almost too good to be true. Can I use it to implement the Google Datastore api? I'm trying for years to find a suitable backend so that I can leave the Google land. Everything I tried either required a schema or lacked transactions or key namespaces.

Re: Apple open-sources FoundationDB

#54

Post by anarazel » Thu, Apr 19, 2018, 5:36 PM UTC

openasocket wrote: post #10

I hadn't heard of FoundationDB before, so I did some digging into the features: https://apple.github.io/foundationdb/features.html . It seems to claim ACID transactions with serializable isolation, but also says later on that it uses MVCC, slower clients won't slow down operations, and that it allows true interactive queries. I didn't think an MVCC implementation could provide that level of isolation, and I'm not eve…

> I didn't think an MVCC implementation could provide that level of isolation

MVCC needs a bit of additional logic ontop to be serializable - "Serializable snapshot isolation" is a good keyword to search for - But it's definitely possible.

https://courses.cs.washington.edu/courses/cse444/08au/544M/R...

https://drkp.net/papers/ssi-vldb12.pdf

https://wiki.postgresql.org/wiki/Serializable

Edit: Formatting

Re: Apple open-sources FoundationDB

#55

Post by itp » Thu, Apr 19, 2018, 5:37 PM UTC

jgh wrote: post #42

itp wrote: post #40

Earlier quoted context omitted.

Speaking as the original author of this monstrosity of a build system, please be careful before offering praise here. To be clear, there is a top-level, non-recursive Makefile that uses the second expansion feature of GNU make, translating Visual Studio project files into generated Makefile inputs that are transformed into targets to power the build. Although it starts by running `make`, it's about as in-house as a t…

Fair enough, I stand corrected. Superficially it seems like a more pleasant experience than dealing with gn/ninja as an end user.

As an end user it's absolutely better. I'm just torn between pride and embarrassment thinking about how it was implemented.

Re: Apple open-sources FoundationDB

#56

Post by rudedogg » Thu, Apr 19, 2018, 5:38 PM UTC

kawera wrote: post #14

Do we know where/how Apple uses FoundationDB in production ?

Maybe CloudKit? I was looking at the documentation for it recently and it's a key-value store.

Re: Apple open-sources FoundationDB

#57

Post by m0meni » Thu, Apr 19, 2018, 5:38 PM UTC

How's this compare to https://github.com/pingcap/tikv? It's a relatively new distributed KV store written in Rust that also is transactional and backs the new TiDB database.

Re: Apple open-sources FoundationDB

#58

Post by protomyth » Thu, Apr 19, 2018, 5:39 PM UTC

jaboutboul wrote: post #49

cnlwsu wrote: post #47

Earlier quoted context omitted.

https://www.foundationdb.org/download/

And there we go...

I don’t see FreeBSD listed.

Re: Apple open-sources FoundationDB

#59

Post by voidmain » Thu, Apr 19, 2018, 5:40 PM UTC

arthursilva wrote: post #30

This is great news! Unfortunately it looks like they striped out some important things, notably the storage engine (there's now a sqlite fallback). Edit: Apparently it was always sqlite as per replies bellow.

The storage engine is and always was a fairly heavily modified asynchronous version of sqlite's btree. It's been extremely reliable, which was always our top priority, and the performance isn't bad. But honestly when there was a problem with it our development velocity improving it wasn't great.

It's super easily pluggable[1], so now that it is open source people can experiment with other engines. I think there is a lot of room for improvement. Also architecturally it's designed in anticipation of being able to run different storage engines for different key ranges and for different replicas. For example, you might keep one replica in a btree on SSD (for random reads) and two on spinning disks in a log structured engine.

[1] https://github.com/apple/foundationdb/blob/master/fdbserver/...

It looks to me like Apple has made a pretty complete release of the key/value store. What's missing is

(1) Layers! Everything from relational databases to full text search engines to message queues

(2) Monitoring stuff. Unsurprisingly it doesn't look like we have the tools for monitoring log files, etc. Wavefront (also a major user!) is a great commercial solution, but there should be something OSS

Re: Apple open-sources FoundationDB

#60

Post by wwilson » Thu, Apr 19, 2018, 5:43 PM UTC

thefounder wrote: post #53

wwilson wrote: post #2

This is INCREDIBLE news! FoundationDB is the greatest piece of software I’ve ever worked on or used, and an amazing primitive for anybody who’s building distributed systems. The short version is that FDB is a massively scalable and fast transactional distributed database with some of the best testing and fault-tolerance on earth[1]. It’s in widespread production use at Apple and several other major companies. But the…

I'm not familiar with FDB but what you say sounds almost too good to be true. Can I use it to implement the Google Datastore api? I'm trying for years to find a suitable backend so that I can leave the Google land. Everything I tried either required a schema or lacked transactions or key namespaces.

As an existence proof: before the acquisition we built an ANSI SQL database and a wire-compatible clone of the MongoDB API.

I see no reason you wouldn't be able to implement Datastore. In fact here's a public source claiming that Firestore (which I believe is its successor) is implemented on top of Spanner: https://www.theregister.co.uk/2017/10/04/google_backs_up_fir...