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<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>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 size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>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 size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>Comments?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'>Edson.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 color=black face=Tahoma><span lang=EN-US
style='font-size:10.0pt;font-family:Tahoma;color:windowtext;font-weight:bold'>From:</span></font></b><font
size=2 color=black face=Tahoma><span lang=EN-US style='font-size:10.0pt;
font-family:Tahoma;color:windowtext'> serusers-bounces@lists.iptel.org
[mailto:serusers-bounces@lists.iptel.org] <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 lang=EN-US
style='color:windowtext'><o:p></o:p></span></font></p>
</div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'>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 size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Samuel,</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'>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 size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;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 size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;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 size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>TIA</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=blue face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:blue'>Gerry</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'>
<p class=MsoNormal style='margin-bottom:12.0pt'><font size=2 color=black
face=Tahoma><span style='font-size:10.0pt;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:12.0pt'><font size=3 color=black
face="Times New Roman"><span style='font-size:12.0pt'><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 size=3 color=black
face="Times New Roman"><span style='font-size:12.0pt'>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 size=2 color=black face=Arial><span style='font-size:
10.0pt;font-family:Arial'>Hi All</span></font><o:p></o:p></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;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 size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'> <o:p></o:p></span></font></p>
</div>
<div>
<p class=MsoNormal><font size=2 color=black face=Arial><span style='font-size:
10.0pt;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:12.0pt'><font size=3 color=black
face="Times New Roman"><span style='font-size:12.0pt'><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 size=3 color=black face="Times New Roman"><span
style='font-size:12.0pt'><o:p> </o:p></span></font></p>
</blockquote>
<pre wrap=""><font size=2 color=black face="Courier New"><span
style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre
style='text-align:center'><font size=2 color=black face="Courier New"><span
style='font-size:10.0pt'>
<hr size=4 width="90%" align=center>
</span></font></pre><pre><font size=2 color=black face="Courier New"><span
style='font-size:10.0pt'><o:p> </o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt'>_______________________________________________<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt'>Serusers mailing list<o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt'><a
href="mailto:Serusers@lists.iptel.org">Serusers@lists.iptel.org</a><o:p></o:p></span></font></pre><pre><font
size=2 color=black face="Courier New"><span style='font-size:10.0pt'><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
size=2 color=black face="Courier New"><span style='font-size:10.0pt'> <o:p></o:p></span></font></pre></div>
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