[Zope] Static fail-over

[bak (kedai)]

On Tuesday 22 January 2002 08:48 am, Chris McDonough wrote:
> Linux Virtual Server works well also as a load balancer.  Additionally,
> Toby Dickenson's recent patch for Zope that allows it to peer with Squid as
> an ICP server (http://www.zope.org/Members/htrd/icp) is a really
> interesting thing; it allows for easy failover at the app level as well as
> rudimentary balancing at the IP level.  In comparison, LVS requires that
> you poll each Zope behind the balancer every so often if you want to detect
> a failure and react, and unlike any of the fancy $30k load balancers it
> doesn't look at HTTP response codes to decide if a server returning a "503"
> error for instance can be taken out of rotation.  Zope as an ICP peer has
> this built-in because it takes the first nonerror response it gets from any
> Squid peer.
>

Look at piranha (ha.redhat.com) which is a LVS +some other tools.

i'm current ly using piranha to loadbalance zeoclients with nanny(piranha 
tool) set to check for zeo clients availability  by checking the HTTP 
response (200).  if nanny receives a 200, all's ok.  else, nanny will take 
the particular zeo client out of available zeo pool, and add it when it gets 
the proper response automatically.