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I'm not sure if I understand your scenario. A stateless proxy would
need a peer for hardware failures and "a bunch of servers" sounds
expensive and I'm not sure what you gain. Could you provide some
details? (The dispatcher module can be used for stateless proxy; using
a SER for load balancing. You can also use 302 REFER to divide load
across registrars. However, regardless how you do it, you need some
routing between SER servers to make sure that messages to a UA go
through the SER server the UA contacted as first hop).<br>
g-)<br>
<br>
Edson wrote:
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<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: navy;" lang="EN-US">Correct
me if I’m
wrong, but since SER is capable to handle tens or hundreds of thousands
of SIP
messages per second, why not cut this number down to thousands and
compose a HA
and Redundancy solution combining some stateless proxy in front of a
bunch of
servers using cache based (like in 2 – MySQL cluster, p.ex.)? The
stateless
proxy could have some local replication (two peers: one active and one
inactive) sharing a common IP (registered on SRV) for HA, and the
geographic
issue could be achieved with a complete replication of this set.<o:p></o:p></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: navy;" lang="EN-US"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: navy;" lang="EN-US">The
down-point in this
approach is that in a geographic switch there is no guarantee that the
clusters
would be totally consistent between the two sets. The fall can (and
Murphy says
it will) occur just before, or in the middle, a big replication DB
operation. But
if You can accomplish that than I see this as a good solution.<o:p></o:p></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: navy;" lang="EN-US"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: navy;" lang="EN-US">Comments?<o:p></o:p></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: navy;" lang="EN-US"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: navy;" lang="EN-US">Edson.<o:p></o:p></span></font></p>
<p class="MsoNormal"><font color="navy" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: navy;" lang="EN-US"><o:p> </o:p></span></font></p>
<div
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<div>
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color="black" face="Times New Roman" size="3"><span
style="font-size: 12pt; color: windowtext;" lang="EN-US">
<hr tabindex="-1" align="center" size="2" width="100%"></span></font></div>
<p class="MsoNormal"><b><font color="black" face="Tahoma" size="2"><span
style="font-size: 10pt; font-family: Tahoma; color: windowtext; font-weight: bold;"
lang="EN-US">From:</span></font></b><font color="black" face="Tahoma"
size="2"><span
style="font-size: 10pt; font-family: Tahoma; color: windowtext;"
lang="EN-US"> <a class="moz-txt-link-abbreviated" href="mailto:serusers-bounces@lists.iptel.org">serusers-bounces@lists.iptel.org</a>
[<a class="moz-txt-link-freetext" href="mailto:serusers-bounces@lists.iptel.org">mailto:serusers-bounces@lists.iptel.org</a>] <b><span
style="font-weight: bold;">On
Behalf Of </span></b>Greger V. Teigre<br>
<b><span style="font-weight: bold;">Sent:</span></b> sexta-feira, 7
de julho de
2006 06:49<br>
<b><span style="font-weight: bold;">To:</span></b> G.Jacobsen<br>
<b><span style="font-weight: bold;">Cc:</span></b> seruser List<br>
<b><span style="font-weight: bold;">Subject:</span></b> Re:
[Serusers] Global
Failover Server</span></font><font color="black"><span
style="color: windowtext;" lang="EN-US"><o:p></o:p></span></font></p>
</div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;">Yes, but this depends on your
deployment setup and
policies. Obviously, you cannot support all features with all UAs.
Three-way
conferencing for example. There's no guarantee that REFER and NOTIFYs
work for
three random UAs from different vendors. There are still too many bugs
around.
So, you need to say: If you have this and that UA, you will probably
not get
three-way conferencing. Not much difference from saying: If you have
this
and that UA, you may experience service outages.<br>
<br>
There are several ways of creating server-side redundancy and
scalability.
Unfortunately, none are trivial. There are three I have heard have been
successfully used in large-scale setups:<br>
1. Cacheless usrloc with a mysql cluster as back-end DB combined with
implementation of the Path header (to find the registrar of a given
UA). No
replication across servers<br>
2. Multiple SER registrars, each with a standalone, local DB and where
SIP is used to replicate registrations. By storing replications from a
peer in a location_peer1 table and then lookup using this table, you
can route
INVITEs to the registrar being able to pinhole the NAT in front of a
given UA<br>
3. Each SER is connected to a single mysql DB cluster as in #1, but
since
usrloc also is in memory (cacheless usrloc is not used), replication is
done
between the SER servers and save_memory() is used to store the location
only in
memory (the registrar updates the cluster with save())<br>
<br>
Each of these three can be combined with either:<br>
a. call-id sticky front-end load balancer (commercial or modified LVS) <br>
b. DNS SRV<br>
c. Linux HA creating two and two peers<br>
<br>
Only b) combined with either 1) or 3) or 2+c) can give geographic,
client and
server-side redundancy and scalability.<br>
<br>
Scalability and redundancy is sort of a pet project of mine... I would
like to
see a simple, clear-documented and code-supported setup that satisfies
most
common requirements. Currently I'm leaning against #2 (which actually
can be
implemented in vanilla SER 0.9.x, but would be easier and better with
built-in
support). I'm thinking about a setup where two and two servers are
peers to eachother
using Linux HA. Both servers would have one active SER instance and one
inactive ready for taking over for the peer.<br>
<br>
I have posted this overview to:<br>
<a
href="http://www.iptel.org/drupal/failover_redundancy_and_scalability_overview">http://www.iptel.org/drupal/failover_redundancy_and_scalability_overview</a><br>
<br>
See also:<br>
<a href="http://www.iptel.org/drupal/ser/wishlist">http://www.iptel.org/drupal/ser/wishlist</a><br>
<br>
g-)<br>
G.Jacobsen wrote: <o:p></o:p></span></font></p>
<div>
<p class="MsoNormal"><font color="blue" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: blue;">Samuel,</span></font><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;">Do you happen to know what
percentage of UAs out there
are really "Compliant" UAs ?<o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="blue" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: blue;">My
impression so far regarding SRV DNS
records is that they are theoretically a nice feature but unfortunately
almost
useless since one needs to cater for those non-compliant UAs anyway. I
would
love to be convinced of the contrary.</span></font><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="blue" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: blue;">Can anyone
supply real usage figures
regarding compliant/non-compliant UAS ?</span></font><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="blue" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: blue;">TIA</span></font><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="blue" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial; color: blue;">Gerry</span></font><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<blockquote style="margin-top: 5pt; margin-bottom: 5pt;">
<p class="MsoNormal" style="margin-bottom: 12pt;"><font
color="black" face="Tahoma" size="2"><span
style="font-size: 10pt; font-family: Tahoma;">-----Original
Message-----<br>
<b><span style="font-weight: bold;">From:</span></b> <a
href="mailto:serusers-bounces@lists.iptel.org">serusers-bounces@lists.iptel.org</a>
[<a href="mailto:serusers-bounces@lists.iptel.org">mailto:serusers-bounces@lists.iptel.org</a>]<b><span
style="font-weight: bold;">On Behalf Of </span></b>samuel<br>
<b><span style="font-weight: bold;">Sent:</span></b> Donnerstag, 6.
Juli 2006
14:52<br>
<b><span style="font-weight: bold;">To:</span></b> Ritesh Jalan<br>
<b><span style="font-weight: bold;">Cc:</span></b> seruser List<br>
<b><span style="font-weight: bold;">Subject:</span></b> [Bulk] Re:
[Serusers]
Global Failover Server</span></font><o:p></o:p></p>
<p class="MsoNormal" style="margin-bottom: 12pt;"><font
color="black" face="Times New Roman" size="3"><span
style="font-size: 12pt;"><br>
Look at RFC 3623.<br>
Cofigure two SRV entries in
your DNS, one pointing to the UAS SERver and another to the UK server.
"Compliant" UAs will try to contact the other proxy upon failure of
their current one.<br>
<br>
Samuel.<o:p></o:p></span></font></p>
<div>
<p class="MsoNormal"><span class="gmailquote"><font color="black"
face="Times New Roman" size="3"><span style="font-size: 12pt;">2006/7/5,
Ritesh Jalan
<<a href="mailto:ritesh.j@net4.in">ritesh.j@net4.in</a>>:</span></font></span>
<o:p></o:p></p>
<div>
<div bgcolor="#ffffff">
<div>
<p class="MsoNormal"><font color="black" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">Hi All</span></font><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">Pls. guide me how can we
implement failover on SIP
Server located globally, Like one server in USA another in UK. </span></font><o:p></o:p></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"> <o:p></o:p></span></font></p>
</div>
<div>
<p class="MsoNormal"><font color="black" face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">Ritesh Jalan <br>
Mobile: 91-9818616329 <br>
MSN: <a href="mailto:ritesh_jalan@hotmail.com" target="_blank">ritesh_jalan@hotmail.com</a>
</span></font><o:p></o:p></p>
</div>
</div>
</div>
<p class="MsoNormal" style="margin-bottom: 12pt;"><font
color="black" face="Times New Roman" size="3"><span
style="font-size: 12pt;"><br>
_______________________________________________<br>
Serusers mailing list<br>
<a href="mailto:Serusers@lists.iptel.org">Serusers@lists.iptel.org</a><br>
<a href="http://lists.iptel.org/mailman/listinfo/serusers"
target="_blank">http://lists.iptel.org/mailman/listinfo/serusers</a><br>
<br>
<o:p></o:p></span></font></p>
</div>
<p class="MsoNormal"><font color="black" face="Times New Roman"
size="3"><span style="font-size: 12pt;"><o:p> </o:p></span></font></p>
</blockquote>
<pre wrap=""><font color="black" face="Courier New" size="2"><span
style="font-size: 10pt;"><o:p> </o:p></span></font></pre>
<pre style="text-align: center;"><font color="black"
face="Courier New" size="2"><span style="font-size: 10pt;">
<hr align="center" size="4" width="90%">
</span></font></pre>
<pre><font color="black" face="Courier New" size="2"><span
style="font-size: 10pt;"><o:p> </o:p></span></font></pre>
<pre><font color="black" face="Courier New" size="2"><span
style="font-size: 10pt;">_______________________________________________<o:p></o:p></span></font></pre>
<pre><font color="black" face="Courier New" size="2"><span
style="font-size: 10pt;">Serusers mailing list<o:p></o:p></span></font></pre>
<pre><font color="black" face="Courier New" size="2"><span
style="font-size: 10pt;"><a href="mailto:Serusers@lists.iptel.org">Serusers@lists.iptel.org</a><o:p></o:p></span></font></pre>
<pre><font color="black" face="Courier New" size="2"><span
style="font-size: 10pt;"><a
href="http://lists.iptel.org/mailman/listinfo/serusers">http://lists.iptel.org/mailman/listinfo/serusers</a><o:p></o:p></span></font></pre>
<pre><font color="black" face="Courier New" size="2"><span
style="font-size: 10pt;"> <o:p></o:p></span></font></pre>
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