Re: [Opensync-devel] OpenSync: fragmentation is harmful

[Graham C. <g+o...@co...>]

On Monday 03 January 2011 13:32:52 Patrick Ohly wrote:
> In this email I'd like to appeal to the OpenSync developers to
> reconsider whether keeping OpenSync around really helps Linux and open
> source syncing. 

Patrick,

Thanks for your well considered thoughts.

I am a small (although fairly long term) contributor to OpenSync, and I have 
no particular desire to continue it if it is not going to be successful or 
there is a better alternative.  Of course, I realise there are others who have 
invested much more time and effort than I have, for which I am extremely 
grateful, and who may feel much more strongly about it than I do.

Speaking personally, my desire is to be able to synchronise my various devices 
and services, which include SyncML devices (of various flavours, each with 
their own quirks, bugs and features), GPE (which I continue to support), KDE 
(kontact) and Outlook/Exchange (for which I have limited, one-way support 
using flat files and OWA).  I am happy to contribute to a project which has a 
reasonable prospect of supporting those various devices.

I have learnt, over the years, that syncing is much harder than it appears at 
first sight!  I will admit that I no longer fully understand the OpenSync 
architecture and design so I can't really comment on your view that it is too 
complex and will not achieve its goals.

I do feel that the plugin API, and the format convertors, seem to be largely 
useful.  Certainly for the GPE plugin it is not too hard to implement the 
required API and it seems to include pretty much the things that are likely to 
be required.  I suspect that both discovery and capabilities may be over-
complex, and I also think the flow-control (memory usage, timeout) problem is 
still not solved (which is partly my fault as I tried to solve it!).  But the 
basic plug-in architecture seems useful and I do wonder whether any of it 
could be re-used.

> Of course I am thinking of SyncEvolution here. It already works very
> well for SyncML. I also have support for additional protocols, which I
> will be able to publish soon. I think it would be worthwhile successor
> of OpenSync, but obviously I'll need help to cover all the use cases
> that you were shooting for with OpenSync.

I do not have a good feel for what SyncEvolution can and cannot do: can you 
provide more information?  One thing is the device access protocols, of 
course, but even if we all joined you and helped implement those, how would 
SyncEvolution compare with what OpenSync is intended to do?  

For example, does it only handle pair-wise sync?  If so, what is the 
implication of that restriction (do you have to designate one of your devices 
as master and sync everything else to it)?

Does it handle devices that have bugs or limited implementations (issues like 
capabilities and merging)?  What about missing unique IDs?  Conflicts?  And the 
many other issues that OpenSync has been adding complexity while trying to 
solve?

In summary, I would like to understand why you feel that redirecting our 
efforts to SyncEvolution has any greater chance of success in solving the hard 
problems of syncing.  

By the way, I do agree with your analysis of Buteo -- at the MeeGo summit it 
became clear that Buteo is not trying to solve the sync problem, it is more 
like a scheduler and manager.

Graham