[Message Prev][Message Next][Thread Prev][Thread
Next][Message Index][Thread Index]
Re: xAP EOM identifier in xAP v1.3
--0014852f5fa49823600473d5625d
Content-Type: text/plain; charset=windows-1252
Content-Transfer-Encoding: quoted-printable
2009/9/17 Edward Pearson <edward.mailgroup@xxxxxxx>
>
>
> > Is a TCP hub going to relay all traffic to all TCP endpoints?
That
> won't scale very well...
>
>
>
> Yes it would forward all traffic. How does that create a scalability
> problem Patrick? Obviously there=92s more traffic, now o(n) rather
than o=
(1),
> but how many clients do you reckon you=92d need to have before
there=92d =
be a
> problem and where do you think the problem might occur?
>
>
>
Your wifi bandwidth gets eaten up o(n) for number of wifi endpoints, the bw
is contended for across all wifi endpoints of course, and depending on what
else you use wifi for and how chatty your xAP network is and how many xAP
endpoints you have, this could be an issue - especially on earlier 802.11b
nets. If filtering is implemented as per Kevin's suggestion, the problem
pretty much vanishes. Hub software wise, I think the engineering problem
looks pretty similar to a web server (or xmpp server), but with longer
live=
d
connections, so I imagine a well designed hub would be able to cope with a
few hundred concurrent connections before getting bogged down - and then
yo=
u
could just add another hub, rinse & repeat.
> > is there merit in some kind of referrer system to allow for
> load-balancing and automated failover of tcp connections across more
than
> one hub?
>
>
>
> I see no more reason for those kinds of features in a tcp capable
system
> than there are in the current (one hub per vm, udp forwarding)
architectu=
re.
>
>
>
One of the strengths of xAP is it's inherent resilience - you lose a PC
somewhere and everything else carries on working apart from the locally
outage on the affected PC. In moving to a tcp hub, loss of the hub not only
affects the machine on which the hub is running, but all the end points
which are remotely connected to that hub. Based on past experience, I think
the wife would see hub fail over as a concrete requirement round these
part=
s
:-)
P.
--0014852f5fa49823600473d5625d
Content-Type: text/html; charset=windows-1252
Content-Transfer-Encoding: quoted-printable
<head>
<style type=3D"text/css">
<!--
/* start of attachment style */
.ygrp-photo-title{
clear: both;
font-size: smaller;
height: 15px;
overflow: hidden;
text-align: center;
width: 75px;
}
div.ygrp-photo{
background-position: center;
background-repeat: no-repeat;
background-color: white;
border: 1px solid black;
height: 62px;
width: 62px;
}
div.photo-title=20
a,
div.photo-title a:active,
div.photo-title a:hover,
div.photo-title a:visited {
text-decoration: none;=20
}
div.attach-table div.attach-row {
clear: both;
}
div.attach-table div.attach-row div {
float: left;
/* margin: 2px;*/
}
p {
clear: both;
padding: 15px 0 3px 0;
overflow: hidden;
}
div.ygrp-file {
width: 30px;
valign: middle;
}
div.attach-table div.attach-row div div a {
text-decoration: none;
}
div.attach-table div.attach-row div div span {
font-weight: normal;
}
div.ygrp-file-title {
font-weight: bold;
}
/* end of attachment style */
-->
</style>
</head>
<html><head>
<style type=3D"text/css">
<!--
#ygrp-mkp{
border: 1px solid #d8d8d8;
font-family: Arial;
margin: 14px 0px;
padding: 0px 14px;
}
#ygrp-mkp hr{
border: 1px solid #d8d8d8;
}
#ygrp-mkp #hd{
color: #628c2a;
font-size: 85%;
font-weight: bold;
line-height: 122%;
margin: 10px 0px;
}
#ygrp-mkp #ads{
margin-bottom: 10px;
}
#ygrp-mkp .ad{
padding: 0 0;
}
#ygrp-mkp .ad a{
color: #0000ff;
text-decoration: none;
}
-->
</style>
</head>
<body>
<!-- **begin egp html banner** -->
<br><br>
<!-- **end egp html banner** -->
<br><br><div class=3D"gmail_quote">2009/9/17
Edward Pearson <span dir=3D"lt=
r"><<a href=3D"mailto:edward.mailgroup@xxxxxxx";>edward.mailgrou=
p@xxxxxxx</a>></span><br><blockquote
class=3D"gmail_quote" styl=
e=3D"border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt
0.8ex; =
padding-left: 1ex;">
=20=20=20=20=20=20=20=20
<div bgcolor=3D"white" link=3D"blue"
vlink=3D"purple" lang=3D"EN-GB">
<br><br>
<div><div class=3D"im">
<p>> Is a TCP hub going to relay all traffic to all TCP
endpoints? That won't scale very well...</p>
<p>=A0</p>
</div><p>Yes it would forward all traffic. How does that create
a
scalability problem Patrick? Obviously there=92s more traffic, now o(n)
rather than o(1), but how many clients do you reckon you=92d need to have
before there=92d be a problem and where do you think the problem might
occur?</p><div class=3D"im">
<p>=A0</p></div></div></div></blockquote><div>Your
wifi bandwidth gets eate=
n up o(n) for number of wifi endpoints, the bw is contended for across all
=
wifi endpoints of course, and depending on what else you use wifi for and
h=
ow chatty your xAP network is and how many xAP endpoints you have, this
cou=
ld be an issue - especially on earlier 802.11b nets. If filtering is
implem=
ented as per Kevin's suggestion, the problem pretty much vanishes.
Hub =
software wise, I think the engineering problem looks pretty similar to a
we=
b server (or xmpp server), but with longer lived connections, so I imagine
=
a well designed hub would be able to cope with a few hundred concurrent
con=
nections before getting bogged down - and then you could just add another
h=
ub, rinse & repeat. <br>
=A0</div><blockquote class=3D"gmail_quote"
style=3D"border-left: 1px solid =
rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left:
1ex;"><div bgc=
olor=3D"white" link=3D"blue" vlink=3D"purple"
lang=3D"EN-GB"><div><div clas=
s=3D"im">
<p>> is there merit in some kind of referrer system to allow
for load-balancing and automated failover of tcp connections across more
th=
an
one hub?</p>
<p>=A0</p>
</div><p>I see no more reason for those kinds of features in a
tcp
capable system than there are in the current (one hub per vm, udp
forwardin=
g)
architecture.</p>
<p><span style=3D"font-size: 11pt; color: rgb(31, 73,
125);">=A0</span></p>=
</div></div></blockquote><div>One of the strengths
of xAP is it's inher=
ent resilience - you lose a PC somewhere and everything else carries on
wor=
king apart from the locally outage on the affected PC. In moving to a tcp
h=
ub, loss of the hub not only affects the machine on which the hub is
runnin=
g, but all the end points which are remotely connected to that hub. Based
o=
n past experience, I think the wife would see hub fail over as a concrete
r=
equirement round these parts :-)<br>
<br>=A0P.<br></div></div>
<!-- **begin egp html banner** -->
<br>
=20=20=20=20
=20=20=20=20
<br>
<!-- **end egp html banner** -->
<div width=3D"1" style=3D"color: white; clear:
both;"/>__._,_.___</div>
<!-- Start Recommendations -->
<!-- End Recommendations -->
<!-- **begin egp html banner** -->
<img src=3D"http://geo.yahoo.com/serv?s=3D97476590/grpId=3D9629476/grpspI=
d=3D1705007709/msgId=3D2025/stime=3D1253260240" width=3D"1"
height=3D"1"> <=
br>
<!-- **end egp html banner** -->
=20=20
<!-- **begin egp html banner** -->
<br>
<div style=3D"font-family: verdana; font-size: 77%; border-top: 1px
s=
olid #666; padding: 5px 0;" >
Your email settings: Individual EmailTraditional <br>
<a href=3D"http://groups.yahoo.com/group/xAP_developer/join;_ylc=3DX3=
oDMTJmMTY5MmZ2BF9TAzk3NDc2NTkwBGdycElkAzk2Mjk0NzYEZ3Jwc3BJZAMxNzA1MDA3NzA5B=
HNlYwNmdHIEc2xrA3N0bmdzBHN0aW1lAzEyNTMyNjAyNDA-">Change settings
via the We=
b</a> (Yahoo! ID required) <br>
Change settings via email: <a href=3D"mailto:xAP_developer-digest@yah=
oogroups.com?subject=3DEmail Delivery: Digest">Switch delivery to
Daily Dig=
est</a> <a href =3D "mailto:xAP_developer-fullfeatured@xxxxxxx?su=
bject=3DChange Delivery Format: Fully Featured">Switch to Fully
Featured</a=
> <br>
<a href=3D"http://groups.yahoo.com/group/xAP_developer;_ylc=3DX3=
oDMTJkNTRkcHJ2BF9TAzk3NDc2NTkwBGdycElkAzk2Mjk0NzYEZ3Jwc3BJZAMxNzA1MDA3NzA5B=
HNlYwNmdHIEc2xrA2hwZgRzdGltZQMxMjUzMjYwMjQw">
Visit Your Group=20
</a>
<a href=3D"http://docs.yahoo.com/info/terms/";>
Yahoo! Groups Terms of Use
</a>
<a href=3D"mailto:xAP_developer-unsubscribe@xxxxxxx?subject=
=3DUnsubscribe">
Unsubscribe=20
</a>=20
<br>
</div>
<br>
<!-- **end egp html banner** -->
<div style=3D"color: white; clear:
both;"/>__,_._,___</div>
</body>
</html>
--0014852f5fa49823600473d5625d--
xAP_Development Main Index |
xAP_Development Thread Index |
xAP_Development Home |
Archives Home
|