[db-wg] NRTM replication inefficiencies

Hi Job,

> On 8 Dec 2017, at 13:51, Job Snijders <job at instituut.net> wrote:
> 
> On Fri, Dec 08, 2017 at 12:56:11PM +0100, Edward Shryane wrote:
>> We could also add an 'end-of-stream' comment in keep-alive mode,
>> something like '%END (starting serial) - (ending serial)', which is
>> output after any backlog of updates.
> 
> Yeah, that would be useful. Is this easy low hanging fruit?
> 

Yes, I've already tested it, this change is straightforward. The only downside is unexpected consequences (i.e. we don't want to break existing clients).

>> It's still possible not to have any updates for a time, which a client
>> may see as a timeout. We could also add a heartbeat mechanism, to
>> periodically output a comment such as '%HEARTBEAT', if there have not
>> been any updates.
>> 
>> Do either of these changes necessitate a new protocol version?
> 
> I doubt it, since "%END XXX - YYY" is a comment.
> 

We could deploy a test NRTM version to our RC environment, for compatibility testing with existing clients.


>> We could also provide NRTM over HTTP(S) WebSockets, that protocol
>> includes support for a Ping/Pong heartbeat mechanism.
> 
> Shouldn't we do away with NRTM at that point and come up with a
> DELTA-like protocol? :)
> 
> Kind regards,
> 
> Job

This is also possible (as a replacement, or in addition to, NRTM).

Regards
Ed