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Syncing data between iOS devices

objc.io

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Re: Syncing data between iOS devices

#2

Post by aaronbrethorst »

This is great. Guys, I love what you're doing with objc.io. Please keep it up!

Everyone else: if you want to help support the site, set up a recurring purchase for the objc.io app in the App Store. It's something ridiculously cheap (for the value provided), like $5.

Also, for more on iOS data syncing and Core Data, this has been a frequent topic of late on Brent Simmons' blog: http://inessential.com

Re: Syncing data between iOS devices

#5

Post by yapcguy »

jchrisa wrote: post #4

Couchbase Lite supports both iOS and Android, and it's all open source. http://mobile.couchbase.com

There's also Cloudant Sync based on CouchDB, which is also open-source and for both iOS and Android. https://cloudant.com/blog/introducing-cloudant-sync/

But how do we choose between CouchBase and CouchDB sync?

Re: Syncing data between iOS devices

#6

Post by tzm »

yapcguy wrote: post #5
jchrisa wrote: post #4

Couchbase Lite supports both iOS and Android, and it's all open source. http://mobile.couchbase.com

There's also Cloudant Sync based on CouchDB, which is also open-source and for both iOS and Android. https://cloudant.com/blog/introducing-cloudant-sync/ But how do we choose between CouchBase and CouchDB sync?

Here is more info on Cloudant Sync: https://cloudant.com/cloudant-sync-walk-thru

Re: Syncing data between iOS devices

#7

Post by Spearchucker »

Interesting read. I've been working on multi-device sync for some time and noticed a few things I ran into. The article speaks of P2P, and goes on to say that transaction logs are uploaded to the cloud. Not P2P then. P2P doesn't work anyway, because there's no guarantee that any two devices are active at any one time. I'm pretty sure my understanding of P2P is limited, compared to the author's.

The other issue is that all approaches described seem to preclude multi-user sync, which is what I've been struggling with. Security also becomes a ball-ache in that changing a password, which unlocks a private key that unlocks a symmetric key that encrypts and decrypts content means storing two copies of any one sync item until all sync clients have the new keys. There are ways of simplifying this, but complexity always creeps back in if I want a zero-knowledge server.

The third thing I'm working on is the idea of multiple, disposable servers. If one goes down, another steps in. If server A offers better comms to device 2 than device 1 which syncs via server B, then device 2 should default to server A without affecting sync scope from device 1.

It's a fascinating subject.

Good article, all the same!

Re: Syncing data between iOS devices

#8

Post by mamcx »

Spearchucker wrote: post #7

Interesting read. I've been working on multi-device sync for some time and noticed a few things I ran into. The article speaks of P2P, and goes on to say that transaction logs are uploaded to the cloud. Not P2P then. P2P doesn't work anyway, because there's no guarantee that any two devices are active at any one time. I'm pretty sure my understanding of P2P is limited, compared to the author's. The other issue is tha…

I'm stuck on this too. I wish to make my invoice app with offline support + async sync, where a company sync several devices, in both ways:

http://stackoverflow.com/questions/21733360/algorithm-that-s...

Re: Syncing data between iOS devices

#9

Post by Aloisius »

mamcx wrote: post #8
Spearchucker wrote: post #7

Interesting read. I've been working on multi-device sync for some time and noticed a few things I ran into. The article speaks of P2P, and goes on to say that transaction logs are uploaded to the cloud. Not P2P then. P2P doesn't work anyway, because there's no guarantee that any two devices are active at any one time. I'm pretty sure my understanding of P2P is limited, compared to the author's. The other issue is tha…

I'm stuck on this too. I wish to make my invoice app with offline support + async sync, where a company sync several devices, in both ways: http://stackoverflow.com/questions/21733360/algorithm-that-s...

We built a custom solution at SeatMe to sync multiple iOS devices with offline support to a central database. There were a lot of edge cases that make it pretty difficult.

There was the embedded mongo (or maybe couchbase?) db available for iOS that does multi-master sync that was being developed for a while that might work though.

Re: Syncing data between iOS devices

#10

Post by mamcx »

Aloisius wrote: post #9
mamcx wrote: post #8

Earlier quoted context omitted.

I'm stuck on this too. I wish to make my invoice app with offline support + async sync, where a company sync several devices, in both ways: http://stackoverflow.com/questions/21733360/algorithm-that-s...

We built a custom solution at SeatMe to sync multiple iOS devices with offline support to a central database. There were a lot of edge cases that make it pretty difficult. There was the embedded mongo (or maybe couchbase?) db available for iOS that does multi-master sync that was being developed for a while that might work though.

I already use sqlite in the device (postgres in the server) and have the app almost finished, so I wish to not switch datastore, specially one that is not relational/transactional.
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