[Freeswitch-users] High Availability Cluster Module for FreeSWITCH

[Steven Ayre]

That covers redundancy in case of a network card or cable failure, but
isn't what partitioning is about. Multiple NICs cannot prevent partitioning.

As an example, partitioning might happen when a network switch between two
network segments fails so you have nodes A+B in segment 1 able to talk to
each other but unable to talk to nodes C+D in segment 2, while C+D can talk
to each other but not A+B.

Pacemaker/corosync contain a lot of algorithms to fence off partitions
without quorum and can resort to things like STONITH if required to force a
node to shutdown rather than risk it causing disruption to the cluster (for
example if it tries to take over traffic to a virtual IP you could end up
in a case where you have two servers sending ARP responses for the same IP).

-Steve



On 10 February 2013 15:27, Eliot Gable <egable+freeswitch at gmail.com> wrote:

> You use multiple NICs in the systems and send heartbeats out all of
> them. There is no other way to do it. Two NICs are required, and 3 are
> recommended.
>
>
> On Sun, Feb 10, 2013 at 6:54 AM, Marcin Gozdalik <gozdal at gmail.com> wrote:
> > I wonder how do you handle network partition? Simply "knowing" which
> nodes
> > are up in a distributed system is hard enough and there is a reason why
> > solutions like pacemaker/corosync have years of development behind them.
> >
> > W dniu niedziela, 10 lutego 2013 użytkownik Eliot Gable napisał:
> >>
> >> The beauty of the module is that it will not require any 3rd party
> >> software to operate. I am designing it to run entirely in-memory using
> >> multi-cast events to communicate between cluster nodes. No external
> >> database will be required to enable the automatic fail over and call
> >> recovery.
> >>
> >> If you have your customers / clients using DNS to point traffic to
> >> your system and you run multiple master nodes with DNS performing load
> >> balancing, you can also make use of the maintenance mode I have
> >> planned which will use a separate IP address and update your DNS
> >> records to remove the master which you put into maintenance mode and
> >> put in the maintenance IP which is assigned to the slave node which is
> >> being promoted as master. This allows calls to drain off the master
> >> while new calls come up on the slave, and then you can gracefully shut
> >> down the master when all calls are finished. Once you are done with
> >> maintenance, you simply bring it back online and it comes up as a
> >> slave or a master as needed (according to your configured master /
> >> slave ratio). The IP which it was using as a master node becomes the
> >> new designated maintenance IP. This is the only case where a 3rd party
> >> software package is required, and it is an optional feature.
> >>
> >>
> >> On Sat, Feb 9, 2013 at 6:49 PM, Gilad Abada <ga at steadfasttelecom.com>
> >> wrote:
> >> > Hey Eliot
> >> >
> >> > Sounds exciting. Which DB will you be using Postgres? I will try to
> >> > get my company to pitch in a few dollars.
> >> >
> >> > Sent from my mobile device.
> >> >
> >> > On Feb 9, 2013, at 12:11 PM, Eliot Gable <egable+freeswitch at gmail.com
> >
> >> > wrote:
> >> >
> >> >> For the past two years, I have been working on and off on a high
> >> >> availability cluster module for FreeSWITCH. If you would like to see
> >> >> HA built into FreeSWITCH directly, instead of dealing with Pacemaker
> +
> >> >> Corosync or other 3rd party systems, please check out the module,
> >> >> voice your support, provide feedback and suggestions, and consider
> >> >> supporting it.
> >> >>
> >> >> Some advantages over a 3rd party solution like Pacemaker include:
> >> >>
> >> >> - Sub-second failure detection and response (meaning it can start
> >> >> recovering calls less than a second after a failure occurs)
> >> >> - Failure detection is built into FreeSWITCH so it can detect
> >> >> conditions which 3rd party modules cannot detect
> >> >> - One shared configuration file between all nodes (no per-node IP
> >> >> configuration required)
> >> >> - No fixed number of nodes
> >> >> - Graceful migration of calls with a maintenance mode (requires DNS)
> >> >>
> >> >> These are just some of the benefits of building a FreeSWITCH-specific
> >> >> HA system. For additional details about the project, please visit:
> >> >>
> >> >> http://wiki.freeswitch.org/wiki/Mod_ha_cluster
> >> >>
> >> >>
> >> >> If you would like to see this project come to fruition, please
> >> >> consider financially supporting it through Kickstarter:
> >> >>
> >> >>
> >> >>
> http://www.kickstarter.com/projects/1175121367/high-availability-cluster-module-for-freeswitch
> >> >>
> >> >>
> >> >>
> >> >> Thanks in advance for anyone who contributes, either with just a
> >> >> shout-out, with feedback and/or suggestions, and especially to those
> >> >> who pledge some financial support.
> >> >>
> >>
> >>
> _________________________________________________________________________
> >> Professional FreeSWITCH Consulting Services:
> >> consulting at freeswitch.org
> >> http://www.freeswitchsolutions.com
> >>
> >> 
> >> 
> >>
> >> Official FreeSWITCH Sites
> >> http://www.freeswitch.org
> >> http://wiki.freeswitch.org
> >> http://www.cluecon.com
> >>
> >> FreeSWITCH-users mailing list
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> >
> >
> >
> > --
> > Marcin Gozdalik
> >
> > _________________________________________________________________________
> > Professional FreeSWITCH Consulting Services:
> > consulting at freeswitch.org
> > http://www.freeswitchsolutions.com
> >
> > 
> > 
> >
> > Official FreeSWITCH Sites
> > http://www.freeswitch.org
> > http://wiki.freeswitch.org
> > http://www.cluecon.com
> >
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> >
>
>
>
> --
> Eliot Gable
>
> "We do not inherit the Earth from our ancestors: we borrow it from our
> children." ~David Brower
>
> "I decided the words were too conservative for me. We're not borrowing
> from our children, we're stealing from them--and it's not even
> considered to be a crime." ~David Brower
>
> "Esse oportet ut vivas, non vivere ut edas." (Thou shouldst eat to
> live; not live to eat.) ~Marcus Tullius Cicero
>
> _________________________________________________________________________
> Professional FreeSWITCH Consulting Services:
> consulting at freeswitch.org
> http://www.freeswitchsolutions.com
>
> 
> 
>
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> http://www.freeswitch.org
> http://wiki.freeswitch.org
> http://www.cluecon.com
>
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