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Horizon 1.0: a realtime, open-source JavaScript back end from RethinkDB

horizon.io

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Re: Horizon 1.0: a realtime, open-source JavaScript back end from RethinkDB

#61

Post by [deleted] »

coffeemug wrote: post #39
amelius wrote: post #37

Earlier quoted context omitted.

Are the transactions optimistic? How does the logic that concurrently applies/rolls-back these transactions over multiple clients work? I'm very interested in this, do you have some internal documentation on it?

Take a look at this comment: https://news.ycombinator.com/item?id=11716145 . TL;DR: currently not optimistic but will be soon; it's fairly simple to do because RethinkDB core has built in support for it. Once the feature lands we'll talk about the implementation in detail.

[deleted]

Re: Horizon 1.0: a realtime, open-source JavaScript back end from RethinkDB

#62

Post by coffeemug »

akanet wrote: post #57
coffeemug wrote: post #7

Hey guys, Slava @ Rethink here. The team is really excited to launch Horizon -- it's based on a lot of feedback from users of very different backgrounds, and we think it will make web development dramatically easier. I've been up for about twenty-four hours, but I'll be around to answer any questions for the rest of the day.

Hey Slava. Interesting stuff - two questions: 1. Do you have something analogous to https://www.firebase.com/docs/web/api/ondisconnect ? Real-time apps often have some manner of presence indicator. Firebase allows you to say "when this client disconnects, set the value of this key to $BLAH". I noticed that Horizon has http://horizon.io/api/horizon/#ondisconnected , but this is just a client-side indication of when yo…

There is currently no "disconnect-and-set" functionality, but it's on the roadmap and will happen soon. It just didn't land into v1.

Since Horizon is backed by RethinkDB, it's transaction properties are the same as that of RethinkDB. Check out this document for the specifics -- http://rethinkdb.com/docs/consistency/.

Re: Horizon 1.0: a realtime, open-source JavaScript back end from RethinkDB

#63

Post by amelius »

coffeemug wrote: post #39
amelius wrote: post #37

Earlier quoted context omitted.

Are the transactions optimistic? How does the logic that concurrently applies/rolls-back these transactions over multiple clients work? I'm very interested in this, do you have some internal documentation on it?

Take a look at this comment: https://news.ycombinator.com/item?id=11716145 . TL;DR: currently not optimistic but will be soon; it's fairly simple to do because RethinkDB core has built in support for it. Once the feature lands we'll talk about the implementation in detail.

Okay I can wait :)

But without optimistic transactions, what sets Horizon apart from just running the transaction-code on the server? If I understand it correctly, the latency will be the same in both cases, i.e., one network round-trip.

Re: Horizon 1.0: a realtime, open-source JavaScript back end from RethinkDB

#65

Post by kevincox »

mglukhovsky wrote: post #64
kevincox wrote: post #56

The Horizon blog could really use a feed that I can subscribe too. I would love to head about all of your future news.

Good idea! We forgot to push a RSS feed. Here it is: http://horizon.io/feed.xml

Thanks! I'm now subscribed :)

It would be even awesomer if you could include the articles in the feed so I don't have to leave my cozy RSS reader :)

Re: Horizon 1.0: a realtime, open-source JavaScript back end from RethinkDB

#66

Post by chris_st »

kcorbitt wrote: post #12

> Horizon is distributed as a standalone server for browser-based JavaScript apps. When you're ready to write custom backend code, you can load the Horizon modules directly in Node.js This is key. Firebase seems great for quick prototypes, but I never built against it because it was unclear (to me at least) how to deal with cases where you want to leave the sandbox and add custom backend functionality that they haven…

Firebase does support a REST API that I've used successfully from Rails. So back-end access works pretty well.

Re: Horizon 1.0: a realtime, open-source JavaScript back end from RethinkDB

#67

Post by akanet »

coffeemug wrote: post #62
akanet wrote: post #57

Earlier quoted context omitted.

Hey Slava. Interesting stuff - two questions: 1. Do you have something analogous to https://www.firebase.com/docs/web/api/ondisconnect ? Real-time apps often have some manner of presence indicator. Firebase allows you to say "when this client disconnects, set the value of this key to $BLAH". I noticed that Horizon has http://horizon.io/api/horizon/#ondisconnected , but this is just a client-side indication of when yo…

There is currently no "disconnect-and-set" functionality, but it's on the roadmap and will happen soon. It just didn't land into v1. Since Horizon is backed by RethinkDB, it's transaction properties are the same as that of RethinkDB. Check out this document for the specifics -- http://rethinkdb.com/docs/consistency/ .

Thanks for that. Can you clarify disconnect behavior in general? Do subscribed changesets resume if your internet blips?

Also, there doesn't seem to be a callback arg in Collection#store: http://horizon.io/api/collection/#store. This is worrying. How do I know if a write succeeded?

Edit: found http://horizon.io/api/collection/#subscribe - you chain subscribe to writes when you care about their success

Re: Horizon 1.0: a realtime, open-source JavaScript back end from RethinkDB

#68

Post by mglukhovsky »

kevincox wrote: post #65
mglukhovsky wrote: post #64

Earlier quoted context omitted.

Good idea! We forgot to push a RSS feed. Here it is: http://horizon.io/feed.xml

Thanks! I'm now subscribed :) It would be even awesomer if you could include the articles in the feed so I don't have to leave my cozy RSS reader :)

I agree! I'll take a look at updating our RSS feed in a bit to include the full articles.

Re: Horizon 1.0: a realtime, open-source JavaScript back end from RethinkDB

#69

Post by coffeemug »

amelius wrote: post #63
coffeemug wrote: post #39

Earlier quoted context omitted.

Take a look at this comment: https://news.ycombinator.com/item?id=11716145 . TL;DR: currently not optimistic but will be soon; it's fairly simple to do because RethinkDB core has built in support for it. Once the feature lands we'll talk about the implementation in detail.

Okay I can wait :) But without optimistic transactions, what sets Horizon apart from just running the transaction-code on the server? If I understand it correctly, the latency will be the same in both cases, i.e., one network round-trip.

Ease of use.

Lack of optimistic updates is a temporary state, though. The vision for Horizon definitely includes this functionality, and we'll make sure it lands ASAP.

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