John Furrier56
Q2: What is the difference between "scale out" and clustering? Any examples would be great
Chris Harney
Clustering adds fault tolerance scale out does not necessarily add ft
Chris Dwan
I think that most scale out systems are "clustered" in one sense of the word. The distinction lies in scale out's ability to expand capacity in a balanced way without introducing bottlenecks.
I am John White
cluster = quorum and more active/passive. Scale out provides all nodes to perform a function.
jeff dinisco
clustering often refers to a dual node system, though not always, in a sense, most traditional scale up storage architecture are actually 2 clustered controllers
Patrick Rogers
Clustering is way to achieve scale-out.
John Furrier
begs the question "how do clusters scale out" :-)
Andrew Miller
historically clustering was about resiliency and removing single points of failure. Let's go back to Novell Cluster Services for instance. Scale-out is focused at very different thigns.
Jeff Hughes
clustering usually means tightly coupled. all the resources are pooled together. scale-out many times just means dividing up the work
Chris Dwan
@csharney Clustering doesn't necessarily add fault tolerance. It's a big place.
Chris Harney
Clustering may not add performance or capacity
Andrew Miller
some companies have sought to merge those though - aka NetApp with scaling out dual controller clusters for their Data Fabric. I'd argue that's not scale-out per se.
I am John White
I don't view clustering as a way to increase horsepower just resiliency. Scale out is all about adding linear available resources.
jeff dinisco
@johna_white true that clusters require quorum, but most scale out systems do as well
Chris Dwan
It seems like some of us are using the word "clustering" to mean "High Availability Pairs." That's pretty old school, isn't it?
Jeff Hughes
@johna_white definitely agree. clustering helps survive, not increase capacity
Kenneth Hui @rubrikInc HQ
Clustering is a tech that can potentially be used for scaling out but it depends on the architecture. For example a master/slave architecture cannot scale out in the same way as a shared-nothing architecture.
I am John White
@dinisco sure, a new age quorum typically exists across all nodes now... not just one place.
Andrew Miller
Clustering focus = keep my services online. Scale-out = grow forever.
Stephen Pao
Often, clustering can be used for scale-out, but also clustering might restrict scale-out to achieve redundancy. So, the terms are somewhat orthogonal.
Dave Vellante
@fdmts I think of a cluster as a logical collection of resources performing the same task...versus a set of discreet resources allocated to different things
Andrew Miller
@fdmts I'll agree that's how I think of it. In some cases cluster capabilities could be a subset of scale-out capabilities.
John Furrier
Didn't Isilon invent "scale out" ? :-)
I am John White
pretty sure that was Al Gore
Dave Vellante
remember the vax cluster in the early 80's...that's old school
Chris Dwan
Yup. And they spent a decade explaining what the hell it meant too.
Andrew Miller
I know I always said scale-out to describe Isilon when at an EMC partner. People seemed to get it and loved the theory.
Patrick Rogers
One example is Oracle RAC. High-availability without much scale.
John Furrier
@dvellante DecNet was a great net protocol stack killed SNA but then TCP took over #OpenWins
Patrick Rogers
Isilon scales but also hits the wall at 144 nodes, so not limitless.
John Furrier
@dvellante VMS (DEC's) OS is what microsoft copied with Windows NT (WNT) one letter after VMS
Christian Smith
Spinnaker :-)
Chris Dwan
@andriven Something about terms like Kleenex and Post-it.
Andrew Miller
@dinisco Good distinction - in scale-out often all resources can be used and during failure scenarios the total resources available diminishes rather than inherent performance decrease.
Dave Vellante
love that story...Dave Cutler