Re: (not so)Quick Update on my progress

[Gregory Maxwell <nullc@nightshade.ml.org>]

On Thu, 26 Jun 1997, Hakan Ardo wrote:

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> On Thu, 26 Jun 1997, Gregory Maxwell wrote:
> 
> Yet another reason to keep sending those agendas telling people when they
> are suppose start there irc clients. Maby be should automate the process
> and allow anyone to add items for the agenda...
That wouldn't be so bad.. Maby I should just set a cron job though.. :)

<snip>
> >  3) Locating other copies of Mnemonic browser on a Lan..
> >     (This is for sibling caching: If it's not in the cache it can
> >      ask other browsers on the lan.. I've simulated this at work
> >      by running multiple copies of squid on a server at work and setting
> >      each copy of netscape to use differnt ones.. Works REAL well)
> 
> Cool! Have you'r test given you any ideas of how much you will gain using
> this kind of tech instead of one centrall cache for the lan?
This is complex.. If there is no central cache then this is just about as
good as one.. And if the nearest central cache is unable to handle the
load or is over a slow link then this is also a win.. If there is a
central cache on the lan then the need for this is diminished but this can
subsidize it's load.. If the central cache serves non mnemonic browsers
then it will prob have a higher hit rate... Real complex issue..

> >     5) I'm also working on some ideas of making it 'smart' about which 
> >     links it precaches first.... Also, this allows it to get the first 
> >     few bytes of an image in order to figure out it's size (http/1.1).
> >     The agressive cacheing is a big speed win when done on the ISP's 
> 
> Yes, there is quite a lot of featurs in the HTTP/1.1 protocoll that allows
> you to tell the server if you need a new copy of the doc or not (eg the
> If-Modified-Since headder to take something simle) and also to tell the
> server which part of a doc you want, if it is the first few bytes of a
> image to decide it's size, or if it's the last part of a file whoes
> transfer was  interrupted.
Yes..
> 
> Now, as I am working on the HTTP protocll, I would like to know which
> features you need so that we can design a nice interace between the http
> module and the cach module...
Okay.. There will be a complete list in my document but in short.. I need
to be handed the headers (mime, cache-control, maxage,expires,date, etc)
from every file you hand me... Also you need to tell me the aprox transfer
time (and if there were other connections at the time), the http version
of the server you are talking to, and if you computer the size of an
object you retreve: give me that too...
 
> >     cache.. It's also a big win on slow links when set right (I.e. If
> >     the page has a small number of links then get the html, Then get the
> >     images off those pages only if they are in the ISP's cache already)
> 
> To know the size of all the images of a page when we first display it is
> also a graet gain, as that would meen we can place everything right from
> the start and there will be no need for moving stuff around, which is
> rather anoying...
Yes.. Thats my plan.. Unfortunatly it needs http/1.1 and most server wont
run that till the end of time.. :)

> 
> > I've also done some work on ways of indexing and searching the cache
> > (Where did I see that page on killer snakes??)....
> 
> This would be realy intresting, especially if you used something lite the
> Z3950 protocoll which will alow one client to easily search in several of
> the upstream caches, or all mnemonic browsers on a LAN.
 Thats something I didn't think of.. We'de have to be careful with privacy
here.. :) I have however thought of a method for asking the upstream
parrent for help in preloading.. :)

> > I hope to have my Cache Specifaction done soon... But I'm so busy with new
> > ideas and trials It's hard to find time to write... I might release a
> > prelimanary version in a week or too..
> >  
> > Oh well, At least you know I'm not dead.. or worse.. you know I'm not lazy!
> > 
> 
> That's Great job! keep it up :)
Thanks!

> 
> - ---------------------------------------------------------------
>  Name:        Hakan Ardo
>  E-Mail:      hakan@debian.org
>  WWW:         http://www.ub2.lu.se/~hakan/sig.html
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>  Interests:   WWW, Programming, 3D graphics
> 
>  Thought for the day: As long as one understands, the
>  spelling does not matter :-)
> - ---------------------------------------------------------------

Re your "thought for the day": Ahh.. I see you've been reading my emails!
heheheh :)