Question

I’m working in a android project the idea is simple:
I just need to record the time that a button is pressed. This part is flat and simple.

The problem is that I need to sync the data in real time (or at least with a very acceptable latency <= 5s). Plus maybe the device could lost connection so we also need that this app could work offline.

In order to achieve that, I need to replicate the data and couchdb seems to offer that.

So, I started to test some examples:

• https://github.com/couchbaselabs/AndroidGrocerySync
• https://github.com/daleharvey/Android-MobileFuton
• https://github.com/couchbase/Android-EmptyApp

But none of them seems to work with this instructions. I mean it works, making the apk file works, the installation success but when the application start it keeps running and do absolutely nothing.

I understand that CouchDB on Android works in the following way:

• Install a service that is CouchDB, so several applications could use this service.
• My android app need to use an API to work with this CouchDB service by doing, POST, GET, PUT, etc.. requests.

My question:

• How do I make work that examples above with the 2.0 API?

Update:

Possible related link: https://groups.google.com/group/mobile-couchbase/browse_thread/thread/83816c0d0f1b050b

Update 2:

It seems that the problem is the CPU version all the tablets that I have are armv5.

Bug related: http://www.couchbase.org/issues/browse/CBMA-13

I haven’t tested in an arm7v cpu yet, but I will do it in a couple of hours.

Update 3:

I have tested twice the app but still doesn’t work with the (ARM)armeabi-7va

Update 4:

I tested the mobile futon example in several devices:

• arm5v: Test failed (emulator and real device), app market and own build.
• arm6v: Test failed (real device), app market and own build.
• arm7v: Test failed (emulator), app market and own build.

It failed is so many ways that I’m so frustrated. And even if I manage to run couchdb in a arm5v, I would have to deal with these major bugs 1 2:

Answer 1

We are using CouchDB on Android as well in a major project. Those 2 bugs have been reported by me and unfortunately they are still not fixed. Nevertheless there are workarounds for these:

CBMA-10:
If you create the target database manually via HTTP PUT before starting the replication you don’t need create_target and everything works fine.

CBMA-3:
If you want to start replications through calling _replicate and the thread still blocks after replication has been cancelled you can cancel this the request manually. Unfortunately there is a bug on some android versions so that calling httpRequest.abort() does not work (see http://code.google.com/p/android/issues/detail?id=7933). You could work around this by injecting a customized SocketFactory to get access to the socket used by the request and call shutdownInput() which causes the request to be aborted.
Another alternative would be using replicator database (see https://gist.github.com/832610). In that case there is no blocking thread during the replication but you have to poll the replicator database in order to recognize when replication has been finished.

In addition to those issues there are still other problems when using CouchDB’s replication mechanism on mobile platforms. The implementation has not been fully addopted to support the mobile scenario yet. So replications my hang for example if network connectivity is not stable. Furthermore there is a retry mechanism with exponential back-off which is suitable for server installations but not on mobile platforms where a connection loss is a regular event. So, in general, you have to decide carefully if you already want to use mobile CouchDB in this early state. Maybe you should delay your decision until the first official GA release (the guys from Couchbase announced that for december).