[jdev] Pubsub items' timestamps

[Sergey Dobrov]

On 04/14/2011 07:33 PM, Dave Cridland wrote:
> On Thu Apr 14 13:17:13 2011, Sergey Dobrov wrote:
>> I have working prototype of microblogging service using PEP and Pubsub
>> with code name LiJ. Since my initial message I had some problems and I
>> wish to solve them but I don't know how I can interact with XSF more
>> effectively.
>>
>>
> The XSF has a number of lists - there's the standards at xmpp.org list, for
> example, which is geared toward general stanards work, and there's
> various specific lists, such as pubsub at xmpp.org and social at xmpp.org,
> both of which might be relevant here.

Thanks

> 
> 
>> Presence based notifications is good idea but it can't be the only way
>> to solve it. I think that we need a possibility to manually request
>> items since some time moment. I wish to specify that it's important to
>> send not only new items notifications but items retract notifications
>> too.
> 
> The problem with sending retraction notices is basically that a
> retraction is a deletion, and once we're storing these, it means storing
> tombstones. I have a general aversion to storing tombstones.

I understand this and agree but otherwise it will be very hard to sync
local copy of node and remote. (For example, in my blog web interface to
it acts as aggregator: it subscribes to all users and put posts to
database to represent them in web. if aggregator is down for any reason
removed posts will be permanently forgot at web). Obviously, service can
just retrive all items IDs for a node and check if all stored IDs still
there but for long threads it may be overhead. Another way is to make
retracted items just empty but this seems to be dirty decision too...

> 
>> I have some other suggestions to pubsub protocol based on experience of
>> usage by microblogging system development and if you wish to solve the
>> problems I will post them here or somewhere you wish.
> 
> Here is OK, but social, pubsub, or standards might be best.
Ok, thanks

> 
> Dave.


-- 
With best regards,
Sergey Dobrov,
XMPP Developer and JRuDevels.org founder.