Re: [WebDNA] HTTP Streaming - POSSIBLE!

This WebDNA talk-list message is from

2010


It keeps the original formatting.
numero = 105569
interpreted = N
texte = >> Which included a script that reloaded itself=20 >> upon the creation of the next sequential file. >=20 > I already have a mockup of my auction site working with a simple = meta-refresh in an iframe, so I don't see how your approach is going to = solve any problems for me. =20 >=20 > The problems I am anticipating are latency and overhead. Maybe I can = get rid of some of that with XMLHTTPRequest, but I don't think it's = going to help much, because even though Javascript can be programmed to = open a new server connection via XMLHTTPRequest as soon as the last one = closes, the browser still has to repetitively open and close these = connections -- every second or two at a minimum if I'm hoping to keep = the browsers updated with the most recent bid price.=20 >=20 > Unfortunately this polling must be initiated by the browser, not by = the server, and this means as many as a couple thousand connections per = second -- just to CHECK to see if the data has been updated. If the = data has not been updated then it's a wasted connection because the = connection still has to be opened, then the current data sent (again), = then the connection closed. >=20 > A better alternative might be to "keep the connection open" and send = each update to the browser as it happens, over the same open connection. = This gets rid of the latency inherent in polling once each second = because the data gets sent immediately instead of waiting to be sent = upon the next polling request ... and it gets rid of most of the = overhead inherent in building up and tearing down all those connections. >=20 > Unfortunately webdna is not appropriate for this type of application, = so I've come up with a work-around meta-refresh / iframe technique as a = possible alternative. It's not the best alternative, that's for sure, = but it's a potential solution that I can understand. I only hope that = webdna is fast enough to respond to all those connections. >=20 > Or I hope to find a better alternative ... Ken, google for "long polling" + your favourite javascript framework. Best, Christer ************************************************************* Christer Olsson PO Box 9160 Phone +46 40 25 85 85 Ljusa Id=E9er AB SE-200 39 Malmo Fax +46 40 25 85 89 Kantyxegatan 5 Sweden http://www.ljusaideer.se Associated Messages, from the most recent to the oldest:

    
  1. Re: [WebDNA] HTTP Streaming - POSSIBLE! (Kenneth Grome 2010)
  2. Re: [WebDNA] HTTP Streaming - POSSIBLE! (Scott Walters 2010)
  3. Re: [WebDNA] HTTP Streaming - POSSIBLE! (Kenneth Grome 2010)
  4. Re: [WebDNA] HTTP Streaming - POSSIBLE! (Kenneth Grome 2010)
  5. Re: [WebDNA] HTTP Streaming - POSSIBLE! (Scott Walters 2010)
  6. Re: [WebDNA] HTTP Streaming - POSSIBLE! (Christer Olsson 2010)
  7. Re: [WebDNA] HTTP Streaming - POSSIBLE! (Kenneth Grome 2010)
  8. RE: [WebDNA] HTTP Streaming - POSSIBLE! ("Olin Lagon" 2010)
  9. Re: [WebDNA] HTTP Streaming - POSSIBLE! (Scott Walters 2010)
>> Which included a script that reloaded itself=20 >> upon the creation of the next sequential file. >=20 > I already have a mockup of my auction site working with a simple = meta-refresh in an iframe, so I don't see how your approach is going to = solve any problems for me. =20 >=20 > The problems I am anticipating are latency and overhead. Maybe I can = get rid of some of that with XMLHTTPRequest, but I don't think it's = going to help much, because even though Javascript can be programmed to = open a new server connection via XMLHTTPRequest as soon as the last one = closes, the browser still has to repetitively open and close these = connections -- every second or two at a minimum if I'm hoping to keep = the browsers updated with the most recent bid price.=20 >=20 > Unfortunately this polling must be initiated by the browser, not by = the server, and this means as many as a couple thousand connections per = second -- just to CHECK to see if the data has been updated. If the = data has not been updated then it's a wasted connection because the = connection still has to be opened, then the current data sent (again), = then the connection closed. >=20 > A better alternative might be to "keep the connection open" and send = each update to the browser as it happens, over the same open connection. = This gets rid of the latency inherent in polling once each second = because the data gets sent immediately instead of waiting to be sent = upon the next polling request ... and it gets rid of most of the = overhead inherent in building up and tearing down all those connections. >=20 > Unfortunately webdna is not appropriate for this type of application, = so I've come up with a work-around meta-refresh / iframe technique as a = possible alternative. It's not the best alternative, that's for sure, = but it's a potential solution that I can understand. I only hope that = webdna is fast enough to respond to all those connections. >=20 > Or I hope to find a better alternative ... Ken, google for "long polling" + your favourite javascript framework. Best, Christer ************************************************************* Christer Olsson PO Box 9160 Phone +46 40 25 85 85 Ljusa Id=E9er AB SE-200 39 Malmo Fax +46 40 25 85 89 Kantyxegatan 5 Sweden http://www.ljusaideer.se Christer Olsson

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