[Freeciv-Dev] Re: Network bandwidth data.

[Raimar Falke <rf13@xxxxxxxxxxxxxxxxx>]

On Fri, Nov 08, 2002 at 06:26:18PM +0100, Juan Uriarte wrote:
> Hi,
> 
> the latest version of the patch is in freeciv/incoming/diff.compress12++.
> It includes cycle counting for linux/i586 and hamming statistics
> for the flags.
> 
>  Random results:
> 
> AI game,  1 controller, 4 obs, 60+ cities, start 1719, after a few turns:
> 
> Cycles per compression call:
>  Total cycles compressing: 16654721537, avg per call: 34058, total calls: 
> 489000
> Started higher, converges around 35000
> 
> An update took ~4000+ packets/player @ 700Mhz == 0.2 seconds/player
> (that update had a 25% compression ratio) (it was around 7kbyte compressed)
> (cpu mobile p3)

While I think I have a better solution for the delta stuff I'm
interrested in the performance of the zlib change. So I changed your
patch a bit to print this information. It is possible that the patch
also did this before but I didn't find it. It prints a lot of info. I
also disabled your delta/caching.

A lot of the packets at turn end are merged and produce results like
this:

2: compressed 202 packets (16794 bytes into 1408 bytes: ratio = 8,383947%) in 
34,451000ms = 487 bytes/ms
2: compressed 185 packets (15577 bytes into 854 bytes: ratio = 5,482442%) in 
22,624000ms = 688 bytes/ms
2: compressed 185 packets (16121 bytes into 928 bytes: ratio = 5,756467%) in 
27,246000ms = 591 bytes/ms

The transfer of the ruleset is also merged:

2: compressed 378 packets (49191 bytes into 18726 bytes: ratio = 38,067939%) in 
56,487000ms = 870 bytes/ms

So with a simple zlib compression you can get at least a factor 10
smaller traffic. Not bad. I estimated (I haven't measured this) the
delta change make the _info_ traffic by a factor 4 smaller.

        Raimar

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