Yeah I was missing this word: SCM => Stateful Call Migration.
From:
freeswitch-users-bounces@lists.freeswitch.org
[mailto:freeswitch-users-bounces@lists.freeswitch.org] On Behalf Of Steve Kurzeja
Sent: Monday, June 15, 2009 12:17
PM
To:
Subject: Re: [Freeswitch-users]
Live Upgrade Techniques
On Sat, Jun 13, 2009 at 4:54 AM, Michael Giagnocavo <mgg@giagnocavo.net> wrote:
Well, Nextone for instance has a database the keeps most of the state of calls, and it’s replicated between the two nodes. (I seem to recall the database was GNU dbm, but I might be mistaken.) However, as of 4.3 anyways, the CDRs still get truncated when there’s any kind of switchover.
BTW in Nextone v4.0.x the GNU db is used for storing configuration data
like storing routes & other bits which is then loaded into memory. Nextone
4.3 and above uses postgres for this configuration data. The actual call state
information is stored in memory and replicated to the standby box via some
custom network protocol.
Stateful call migration would be a very useful feature in FS but I imagine its
way down the roadmap.
But as to the original question of live upgrades, having some form of
load balancing proxy and then bleeding off traffic from the box you want to
upgrade is the most feasible approach, as others have mentioned.
Steve