[Serusers] Loadbalancing / high availability

Jiri Kuthan jiri at iptel.org
Tue Dec 7 09:15:10 CET 2004


Out of curiosity -- how do you replicate data in your database backend?

Thank you,

-jiri

At 04:36 AM 12/7/2004, Michael Shuler wrote:

>I was not aware that there was a dispatcher module (I don't see any docs for
>it on the site).  
>
>
>The Foundry load balances the SIP messages as they come from VoIP phones on
>the Internet over the cluster of SER boxes which then balance the "sessions"
>over ast_data patched Asterisk boxes (since a "session" must continuously go
>to the same Asterisk box to maintain call state within Asterisk).  To
>balance the session from SER over the Asterisk boxes I am using round robin
>DNS where ast.bwsys.net actually expires every second through ast0, ast1,
>ast2, etc.  So SER does a forward("ast.bwsys.net") on the initial INVITE
>messages from the VoIP phones.  The Asterisk boxes conveniently replaces
>ast.bwsys.net with their real IP and SER uses the real IP on all future
>messages automatically until that "session" is done.  The next INVITE from
>the same VoIP phone is then put through the same round robin DNS and may end
>up on a different Asterisk server next time.
>
>
>----------------------------------------
>
>Michael Shuler, C.E.O.
>BitWise Communications, Inc. (CLEC) And BitWise Systems, Inc. (ISP)
>682 High Point Lane
>East Peoria, IL 61611
>Office: (217) 585-0357
>Cell: (309) 657-6365
>Fax: (309) 213-3500
>E-Mail: mike at bwsys.net
>Customer Service: (877) 976-0711 
>
>> -----Original Message-----
>> From: Jiri Kuthan [mailto:jiri at iptel.org] 
>> Sent: Monday, December 06, 2004 1:27 AM
>> To: Michael Shuler; 'Matt Schulte'; serusers at lists.iptel.org
>> Subject: RE: [Serusers] Loadbalancing / high availability
>> 
>> 
>> What is exactly role of ServerIron when SER does load balancing?
>> Are you using SER's dispatcher module?
>> 
>> -jiri
>> 
>> At 05:37 PM 12/1/2004, Michael Shuler wrote:
>> >We use a Foundry ServerIron XL and it seems to work fine.  
>> We do not use SER
>> >as a stateful proxy though.  SER is basically a SIP message 
>> load balancer
>> >across our Asterisk boxes.
>> >
>> >----------------------------------------
>> >
>> >Michael Shuler, C.E.O.
>> >BitWise Communications, Inc. (CLEC) And BitWise Systems, Inc. (ISP)
>> >682 High Point Lane
>> >East Peoria, IL 61611
>> >Office: (217) 585-0357
>> >Cell: (309) 657-6365
>> >Fax: (309) 213-3500
>> >E-Mail: mike at bwsys.net
>> >Customer Service: (877) 976-0711 
>> >
>> >> -----Original Message-----
>> >> From: serusers-bounces at lists.iptel.org 
>> >> [mailto:serusers-bounces at lists.iptel.org] On Behalf Of Matt Schulte
>> >> Sent: Wednesday, December 01, 2004 7:42 AM
>> >> To: serusers at lists.iptel.org
>> >> Subject: RE: [Serusers] Loadbalancing / high availability
>> >> 
>> >> 
>> >> 
>> >> I'm curious what brand load balancer you would use, would it be IP
>> >> based. We tried out a Cisco SLB and had no luck, mainly 
>> >> because it would
>> >> NAT to the servers (more trouble than it's worth?). We were 
>> >> thinking of
>> >> using a heartbeat type failover, similar to what you would do 
>> >> for MySQL:
>> >> 
>> >> http://linux-ha.org/download/
>> >> 
>> >> Has anyone tried this method? We're more concerned about the high
>> >> availability than anything.
>> >> 
>> >> -----Original Message-----
>> >> From: E. Versaevel [mailto:erik at infopact.nl] 
>> >> Sent: Wednesday, December 01, 2004 7:24 AM
>> >> To: serusers at lists.iptel.org
>> >> Subject: [Serusers] Loadbalancing / high availability
>> >> 
>> >> 
>> >> Hello,
>> >> 
>> >> I was wondering if it is necessary for a SIP packet from a 
>> >> specific call
>> >> to always go through the same server?
>> >> 
>> >> For instance, if you have a load balancer distributing 
>> requests over a
>> >> few servers, it is possible that an INVITE ends up on 1 
>> >> server while the
>> >> following INVITE with the credentials ends up on another, 
>> >> would this be
>> >> a problem (ie, break the authorization) or should you use 
>> a SIP aware
>> >> loadbalancer for this (who looks at the callid for 
>> example)? Assuming
>> >> the ser servers are setup to use the same userdatabase (and 
>> >> t_replicate
>> >> to eachother) the picture would be something like this:
>> >> 
>> >>                       |
>> >>                 --------------
>> >>               |loadbalancer|
>> >>                 --------------
>> >>                    |
>> >>                    |
>> >>           --------------------
>> >>           |          |         |
>> >>       -------   -------   -------
>> >>       |     |   |     |   |     |
>> >>       | ser1|   | ser2|   | ser3|
>> >>       |     |   |     |   |     |   
>> >>       -------   -------   -------
>> >> 
>> >> If you setup the servers with the same IP as the load 
>> >> balancer and stop
>> >> them from replying to ARP requests for that IP, replying back 
>> >> thru a NAT
>> >> should not be a problem.
>> >> 
>> >> Just thinking out loud, I could use SER for the load balancing and
>> >> t_relay the packets, however that would require some 
>> >> tampering with the
>> >> VIA records (and I should use a reply to via in that case to the
>> >> original IP the SIP request came from, eg not the load 
>> balancer) this
>> >> way outgoing SIP traffic would not have to go thru the ser 
>> >> loadbalancer
>> >> again to get out, hmm, it might even be possible to use a 
>> route-record
>> >> header to get the packets back at the correct server...
>> >> 
>> >> 
>> >> Kind regards,
>> >> 
>> >> E. Versaevel
>> >> 
>> >> _______________________________________________
>> >> Serusers mailing list
>> >> serusers at lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers
>> >> 
>> >> _______________________________________________
>> >> Serusers mailing list
>> >> serusers at lists.iptel.org
>> >> http://lists.iptel.org/mailman/listinfo/serusers
>> >> 
>> >
>> >_______________________________________________
>> >Serusers mailing list
>> >serusers at lists.iptel.org
>> >http://lists.iptel.org/mailman/listinfo/serusers
>> 
>> --
>> Jiri Kuthan            http://iptel.org/~jiri/ 
>> 
>
>_______________________________________________
>Serusers mailing list
>serusers at lists.iptel.org
>http://lists.iptel.org/mailman/listinfo/serusers

--
Jiri Kuthan            http://iptel.org/~jiri/ 




More information about the sr-users mailing list