On Wed, Apr 16, 2008 at 4:20 AM, Jagi Sarcilla <[EMAIL PROTECTED]> wrote: > what we are looking is the application failover solutions. > without interruption on the application side. > > is it right failover or load balance?
First things first, sorry if almost all are commercial based, that's my experience.I just don't want to spout information to you just by googling around. :) If you can find a comparable free software like pen,then good. But the high level stuff discussed is roughly the same. That's a good point you are making here. There is a distinction, though people lump it the same. What you want is load balancers(resonate for software based or F5 for hardware based), not necessarily failover(VCS,Service Guard,HACMP or SUN Cluster). Seriously, what you want is a tall order and complicated to do. You can use either one, but complicated for both. FYI, if they can spare an SLA within 2-5 minutes of downtime while failover is happening, the best and easier (but still complex) is failover/high availability (HA) all the tiers rather than load balance. Working currently in the financial industry, almost all are using HA. >From the top of my head, the one that i've seen that combines them both is: tier1: load balancers (F5 hardware based duallies) tier2: http/https server farm (apache or IIS or both. No failover. If it dies, it dies. F5 takes care of not using it.) tier3: application server (load balancing is done natively on the software.) tier4: DB server (Using HA.) For keen readers, there is still a small downtime when tier 4 does a failover. If you really want true load balance all the way, be prepared to cough up some money, like Oracle RAC. If you can cobble together free software for this and make it work, i'm interested. And this handles millions of hits per day. Don't bother tailing the logs. :) -- regards, Andre | http://www.varon.ca _________________________________________________ Philippine Linux Users' Group (PLUG) Mailing List http://lists.linux.org.ph/mailman/listinfo/plug Searchable Archives: http://archives.free.net.ph
