Hi Paul, pls help me
I ran into the following problem:
ser1 receives REGISTER from VIP interface; then have to replicate the message to ser2. So
I need to switch between interfaces - send from real IP. Do you know some way doing this
with ser?
Thx in advance,
Tina
Java Rockx <javarockx(a)gmail.com> wrote:
Tina,
I wish I had more information on that, but that LVS stuff is a black art to me. One of our
engineers whipped up an LVS configuration that seems quite happy with the Call-ID
"stickness" you described. All I can say right now is that it is apparently
possible to do this with 100% open source. (i'm keeping my fingers crossed) :-)
Regards,
Paul
On Apr 10, 2005 11:03 PM, Tina <kramarv(a)yahoo.com> wrote:Paul,
thanks a lot, it helps a lot. The thing I do not understand - how you are going to solve
call-id stickness (see my another post). Since we're also use LVS I had to find
something proprietary, I am afraid this is not a best solution, but the only I have
today.
KRs,
Tina
Java Rockx <javarockx(a)gmail.com> wrote:
Tina,
I really don't know how the LVS server is configured because our network guy that we
acquired from RedHat set all that stuff up. I do know that we basically have this set up:
I hope the formatting goes well :-)
+-----------+ +----------+ +-------+ +---------+ +--------------------+
| internet |------| Cisco |------| LVS |-----| Cisco |----| Application |
| cloud | | 3600 | | | | 3600 | | & DB Servers |
+-----------+ +----------+ +--------+ +---------+ +--------------------+
So the "Application & DB Servers" box represents multiple servers (all are
dedicated to their service). These include SER, MySQL, Apache, configuration management,
monitoring, RTP proxies, etc.
MySQL is active-active so we have two-way replication. We only have 2 MySQL servers. And
this is all we plan on ever having as MySQL is more than capable of handling anything ser
can throw at it (given the right hardware).
Each ser server is 100% oblivious to other SER servers except for when handling REGISTER
messages. Here is basically the ser.cfg for each SER server:
listen=10.3.0.221 # this will be 10.3.0.222 on the peer sip proxy
modparam("usrloc", "db_mode", 1) # write-through
route {
if (method=="REGISTER") {
if (src_ip==10.3.0.221) { # ip of peer ser proxy
save_memory("location");
break;
} else {
save("location");
t_replicate("10.3.0.222");
break;
};
};
}
We have identifed a deficiency in the usrloc module urecord.c file whereby when using
write-though mode the save_memory() function still attempt to update MySQL. This is a very
bad thing because it causes a primary key violation on the location table.
Yesterday I posted a patch to serdev to fix this, but today we identified another case
where save_memory() tried to insert in to the location table. I'll post a revised
patch to serdev as soon as I get a chance.
So here is what happens. Assume I have two sip routers and two MySQL servers as:
sip-01 is 10.3.0.221
sip-02 is 10.3.0.222
db-01 is 10.2.0.21
db-02 is 10.2.0.22
Now let's just assume that sip-01 is connected to db-01 and sip-02 is connected to
db-02.
When a SIP UA connects to a sip router (via LVS), assume sip-01 in this example and
REGISTERs, sip-01 will call save("location") which updates/inserts to the
location table. sip-01 then calls t_replicate to sip-02.
sip-02 recieves the REGISTER message and calls save_memory("location") to update
its in-memory cache only. It should never hit db-02.
Now db-01 eventually (within a second or two) replicates to db-02 and now sip-02 is good
to go, even in the event of a restart.
Our difficulties mostly surrounded the fact that ser was inserting the physical IP of eth0
on the server as the top VIA rather than the VIP as required. We solved this by using
record_route_preset() and passing the VIP as the IP. We also had to bring up a dummy
interface in order to get ser to honor the VIP.
Hope this helps.
Regards,
Paul
On Apr 8, 2005 7:19 PM, Tina <kramarv(a)yahoo.com> wrote: Paul,
we are using LVS as well. It creates template connection according to source Ip (e.g. UAC)
and forwards to one of the tunneled IP. I tested this a couple of weeks ago, ser was happy
and inserted VIP into via header, the only issue is to route the calls into right server.
I agree, there is no such thing as SIP-level clustering. However, how would you solve
location problem by DB replication - 1) usrloc does not update from DB....2) even though,
I am afraid it can become bottleneck and lock down users ...
KRs,
Tina
Java Rockx <javarockx(a)gmail.com> wrote:
See my inline comments.
Regards,
Paul
On Apr 8, 2005 1:08 PM, Greger V. Teigre <greger(a)teigre.com> wrote: Hi Tina,
I enjoy reading your posts, thanks a lot for the great
work you are
doing for ser users!
Thanks :-)
I am going to consider that kind of scenario as well
(load balancer
returning Virtual IP address). I think for such configuration server
side has to keep session information and always forward a call to the
right server.
I believe the load balancer can be in front and transparantly translate addresses in the
SIP messages:
User agent always sees a.b.c.d
|
Load balancer with public IP a.b.c.d
| |
ser1 (10.0.0.2) ser2 (10.0.0.3)
Paul: You have a similar load-balancing solution, right? Do you use a commerical load
balancer that you can reveal the name of? :-)
Our platform is 100% open source. Our load balancer is LVS. I have no idea how it actually
works. One if our engineers from RedHat set all that networking stuff up and it's way
beyond me.
The load balancer need to understand SIP (sort of) and use something (ex. IP address of
user agent) to select SER server to send to and rewrite incoming to 10.0.0.2 and 10.0.0.3
respectively and outgoing to a.b.c.d. ser1 and ser2 will happily believe they are alone
and communicate directly with user agent using their own private addresses. Both should
know about all users (usrloc). Paul just recently posted a small patch for a setup where
they use two-way replication between two
That small patch will need a slight revision. We discovered through further testing that
that patch only fixed attempts to INSERT into the location table. We didn't cover the
UPDATE route, unfortunately. I believe Andrew has that patch done and is testing it. So
I'll post it to serdev as soon as we know it works - possibly later today.
mysql servers and where each SER instance will save all REGISTERs it receives from user
agents, but only save to memory those replicated from the other SER peer. Klaus pointed
out that the same can be done by not doing mysql replication, but have one DB for each SER
and just use t_replicate() and save_noreply() (for two servers, for more than two you need
to use forward_tcp()).
I have heard complaints that this approach will generate too much network traffic. Also,
t_replicate() does not guarantee delivery of the replication (forward_tcp is better, but
not fool proof). So, the "best" solution would probably be to hope that
Paul's
I fully agree. Replication at the sip proxy level, IMHO, is not a good idea. From a purist
point of view, replication is not a function of a SIP router - nor should it be. It is a
function of the database and we believe that the MySQL replication is a better approach
from a speed and reliabilty point of view - not to mention that it simplifies the tasks of
the sip router.
recent TCP/UDP patch for network access to FIFO commands get included in the CVS. Then, a
new replication module should use XMLRPC or whatever protocol the patch is using to
forward (in a guaranteed mode) the usrloc information, which then would be injected
directly into SER's memory, just like save() would, and of course in whatever db_mode
you would like. The replicaton module would have to keep a queue (of course, flushed to a
DB or something) in case of network problems, so that the replication would be done
(sooner or later) regardless of problems.
Of course, this is a major undertaking, so for most replication scenarioes, I would
think the forward_tcp() + save_noreply() would work just fine.
g-)
"Greger V. Teigre" <greger(a)teigre.com>
wrote:
I was thinking about a load balancing scenario where the load
balancer will replace the IP addresses.
g-)
---- Original Message ----
From: Tina
To: Greger V. Teigre
Sent: Wednesday, April 06, 2005 09:45 PM
Subject: Re: [Serusers] still no help - usrloc synchronization
Thank you for givingme the scenario with
"restricted IP" NAT, I am
starting to find some acceptable solution.
Unfortunately, "one-public-IP" approach is not free from problems
also. If your SIP router inserts this "one-public-IP" into the VIA
header, the reply routing goes via wrong SIP server...
If your SIP server inserts its real-IP-address - the scenario
mentioned above is still not resolved.
Any comments?
Tina
"Greger V. Teigre" <greger(a)teigre.com> wrote:
See inline.
If you use DNS server for load balancing... the
client receives one
of your domain IP addresses according to SRV. I don't see the
problem
with a call here, cause UAC asks t! he address only once (before
sending INVITE). UAC already has the IP for BYE/reINVITEs. So why
would you replicate INVITEs?
I would never replicate INVITEs, I would just make sure that they are
proxied through the correct SER server (i.e. IP).
The problems depends on your setup. If you have SERs with different
IPs, ex UA1 has registered with server A and UA2 has registered with
server B: If UA2 wants to call UA1 and UA is behind an IP restricted
NAT, server A is stored in the NAT table of the NAT in front of UA1.
If server B sends an INVITE to UA1, the INVITE will be refused by
UA1's NAT.
This is why a "one public IP" in front of a load balancing
cluster probably is a good way to go.
If you use IPVS/LVS... I believe you can force
SER to insert it's
public IP into VIA,! so there is no problem with replies. With
regard
to another requests, I believe load balancer keeps connection
template, then when another request comes it would be forwarded to
the same ser.
Yes. There are different "keys" to use to load balance SIP messages.
One good way from a NAT point of view is to use originating IP
address. What you must remember is that the problem is not on the
server side, but on the client side. The NAT will in many situations
stop incoming UDP packets if the originating ip:port is not already
stored in the NAT table. The Via header does not matter for the NAT.
g-)
Any comments?
"Greger V. Teigre" <greger(a)teigre.com> wrote:
Yes, I believe that is so. But still you get a problem if the NAT is
restricted, port-restricted or symmetric... The best would be to
load>> balance and always make sure that a given client is handled
through a given
SER (REGISTER and INVITEs). That includes forwarding INVITEs from
one
SER to
another... OR you must load balance in front of your servers with
one
common
public IP.
g-)
Matt Schulte wrote:
Ack, I didn't even think about NAT. Would
these be added before it
gets sent off to the second proxy? ie:
if (!src_ip==blah.netlogic.net) {
add_rcv_param();
t_replicate("blah.netlogic.net", "999");
};
-----Original Message-----
From: Greger V. Teigre [mailto:greger@teigre.com]
Sent: Tuesday, April 05, 2005 7:49 AM
To: Matt Schulte; kramarv(a)yahoo.com
! ; Cc: serusers(a)lists.iptel.org
Subject: ! Re: [Serusers] still no help - usrloc synchronization
Well, you still have the NAT issues unless you do load balancing
and your
SER servers have the same public IP.
Have you looked at 0.9.0 nathelper function add_rcv_param() ? It
will add received info to the contact header for the other SER to
process. Haven't really tried yet...
g-)
Matt Schulte wrote:
> I'm starting to lean this direction, using t_replicate and all. I
> could never get usrloc (db mode) to function properly..
> t_replicate is
> a dirty but very effective workaround.
>
> -----Original Message-----
> From: Greger V. Teigre [mailto:greger@teigre.com]
> Sent: Saturday, April 02,! 2005 1:33 AM
> To: kramarv(a)yahoo.com
> Cc: serusers(a)lists.iptel.org
> Subject: Re: [Serusers] still ! no help - usrloc synchronization
>
>
> Have a look at this thread:
>
http://lists.iptel.org/pipermail/serusers/2005-January/014669.html
> g-)
>
> Java Rockx wrote:
>> Tina,
>>
>> I thought I saw you post the other day that you did not want to
>> use t_replicate(), however, this is probably your best bet to
>> getting this
>
>> to work, IMHO.
>>
>> Regards,
>> Paul
>>
>> On Apr 1, 2005 4:08 PM, Tina wrote:
> ! >>
>> ! ;> Hi, please help me, I'm stuck with it!!!!!
>>> I am trying to set up several sers with a shared MySQL database
>>> for location service.
>>>
>>> I set in each ser.cfg:
>>>
>>> modparam("usrloc", "db_mode", 2)
>>> modparam("usrloc",
>>> "db_url","sql://ser:heslo@192.168.25.163/ser")
>>>
>>> and the servers are not synchronized.
>>> The I set
>>> modparam("usrloc", "db_mode", 2)
>>>
>>>
>>> made UAC (Xlite) register to one of the servers.
>>> I see it via usrloc, but there is no record in "location" mySQL
>>> table....So others do not see the client and I'm unable to make
>>> calls....
>>>
>>>
>>> Please help how to work with usrloc and mySQL...
>>>
>>> Tina,
>>> software engineer
>>>
>>> ________________________________
>>> Do you Yahoo!?
>>> Better first dates. More second dates. Yahoo! Personals
>>>
>>>
>>> _______________________________________________
>>> Serusers mailing list
>>> serusers(a)lists.iptel.org
>>>
http://lists.iptel.org/mailman/listinfo/serusers
>>>
>>>
>>>
>>
>> _______________________________________________
>> Serusers mailing list
>> serusers(a)lists.iptel.org
>>
http://lists.iptel.org/mailman/listinfo/serusers
>
> _______________________________________________
> Serusers mailing list
> serusers(a)lists.iptel.org
http://lists.iptel.org/mailman/listinfo/serusers
Yahoo! Messenger
Show us what our next emoticon should look like. Join the fun.
Do you Yahoo!?
Better first dates. More second dates. Yahoo! Personals
Yahoo! Messenger
Show us what our next emoticon should look like. Join the fun.
_______________________________________________
Serusers mailing list
serusers(a)lists.iptel.org
http://lists.iptel.org/mailman/listinfo/serusers
---------------------------------
Do you Yahoo!?
Make Yahoo! your home page
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
---------------------------------
Do you Yahoo!?
Plan great trips with Yahoo! Travel: Now over 17,000 guides!