[Dxspider-support] node & user information

[Dirk Koopman]

Just to add to the information to think about. If you look at the bottom 
of this link:

http://www.dxcluster.org/mrtg/

you can see that actually the C traffic is a slightly higher than the 
A/D traffic.

Dirk

On 16/01/17 17:25, Dirk Koopman via Dxspider-support wrote:
> Hopefully this will answer your recent questions...
>
> Thank you for your answers.
>
> There are PC92 (A) add, (D) delete and (C) node config records.
>
> PC92 A & D records are delayed for (as default and from memory) one 
> minute before sending. There are two reasons for this:
>
> 1) It means that programs that connect, fire dx (and maybe do a couple 
> of others things automatically) then disconnect do not cause PC92 
> records to be sent.
> 2) By waiting some time, the updates (both add and delete) accrete and 
> all the changes sent in just one A and/or D record.
>
> It is the A and D records that cause a very large proportion of the 
> traffic.
>
> The node config (C) records are a different kettle of fish. They are 
> normally sent once every four hours and, in one (sometimes HUGE) 
> record represents the true connection state of a node. This is really 
> a node's backstop "definitive" list of nodes and users to cope with 
> inadequate lossy links and, more importantly a means of newly 
> (re)started nodes getting a cluster configuration within a reasonable 
> period. The default used to be 30 minutes or so and that was quickly 
> changed when it became apparent that this was waaaaay too frequent for 
> 400+ nodes sending 500 -> 3000+ byte C records. one could think of 
> this in disk backup terms with the C record being a full backup of a 
> node's config and A & D records being incremental updates. Increasing 
> the frequency of the C records will, very quickly, become a problem - 
> just by themselves.
>
> In principle one could switch off the A and D records and only lose 
> the "realtime" (or incrementally updated) configuration.
>
> Just for completeness there are PC92 (K) records which are similar to 
> the old PC50 records with some additional information on software and 
> version numbers. They are sent once an hour and are used as remote 
> node "keepalive" notices. If a node doesn't hear any PC92 traffic 
> (A,C,D or K) for three hours then that node and its user connections 
> is removed from local copy of the cluster configuration.
>
> Also, as it stands, if one sends a talk message out to a callsign that 
> is not in the  node's view pf the cluster map, then it is flood routed 
> anyway. This is very much analogous to a "ping".
>
> Dirk