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Re: P3D telnet servers



On 12/1/00 11:17 AM webmaster@badgersoft.org (webmaster@badgersoft.org) 
wrote:

>How about considering some of the Sun JINI (JavaSpaces) or IBM's TSpaces
>technology for distributed computing whereby a set of Servers listen to
>service requests via a master server, from clients. If you did this you
>could possibly use it to 'fill in the gaps' as the footprint moves around
>the globe. 

The way we do it in APRS is the central servers consolidate the data from 
all clients, filtering out duplicates. This would seem like a reasonable 
way to go, merging data from all monitoring stations, essentially 
creating a large diversity receiver. 

This sort of diversity receiver works very well on HF APRS, with 30 or 
more HF gateways listening, it is rare for me not to see on the internet 
a packet I have transmitted on HF.

>It might also be used for sharing the load of storing all those
>frames were going to be getting over the next 10 years.
>
For comparison, the APRS network handles about 350,000 packets every day 
(74 bytes/packet average) serving 300 to 400 clients at any given time. 
This is done with only two central servers, and in fact when one is down 
the other is still able to handle the full load. The load on the 
telemetry server is likely to be much less.

The findu database stores all of these packets (more than 90 million so 
far) in both raw and parsed form. All the data for the last 9 months 
takes up 10 GB, very manageable given hard disk prices these days.

So, I'd say one well-designed server could handle this problem, two on 
different internet backbones would provide nice redundancy. Jini and 
TSpaces seem to be aimed more at tasks which need to be distributed for 
either bandwidth or CPU considerations. It'd work, but I suspect it is 
needlessly complex for the problem at hand.

Steve K4HG

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