What is Grid and Cluster computing means ?

Question

Hi ,
The following terminology is very confusing. Could you please explain. What is this means ? and how they are different from each othere, etc.
- Cluster computing-
- Grid computing
- Parallel computing
- Distributed computing
- supercomputers or conventional supercomputers
Thanks
Siva

Answer 1

Hans has already given an excellent reply. So I shall be just echoing the same and since it's quite early for me in the morning and it's not a weekend for me as well so my reply would be limited.
Grid Computing: What we mean by multiple administrative domains ?As you might have read in the link given by me and also on many other links on the web, there is no defined thing like this available. It's a concept. When in 10g, this concpet finally came, it was completely not possible to define except saying this that we are going to have many servers combined which can do the work for us as like one and we don't need to know which one is working for us and which one note. I remember an example given by HJR, electricity hubs. As being a consumer, we just need to bother about this that when we switch on the tubelight, it should be on. We are really not concerned that from which transformer, the electricity is going to actually come to the tube light. And that's exactly what Grid Computing is , you need a resource, you would get it, from where, you are not supposed to know. And looking at this aspect, this is not something which started happening from 10g only except this that a formal marketing name, Grid Computing , came into the picture. Oracle's RAC(earlier called OPS) is exaclty doing the same since version 6-presenting a multi-system environment as one to you. Now, there is another concept added in it called administrative domains. Again, this IMO, is a term and with the Grid Comptuing concept getting matured, it's implementations are also becoming clear. Like in 11.2 RAC, we have got a concept of Server Pools which means , in a cluster of 4 nodes, you can divide your OLTP work on Node 1 and 2, DWH on Node 3,4. And in these server pools, you can add and remove the nodes on the fly and pools would take care of the things on their own. Now, since we have managed to seggregate the roles of operations in two different set of nodes which are still part of one single cluster, we can manage things differently. And I think that's what can be called(loosely) Administrative Domains. Again, this is just one of the many examples I think as Hasn has mentioned, the definitions would really stand correct in the right context where they are used. And it's also possible that I might have given a completely wrong picture to you as well.
Is Clustering & Distributed computing, are the same ? Multiple computers are involved
Clustering & Distributed computing to compute the data, then what is the difference. ?Well, no, that's not true. Clustering is combining computing power of many computers as one and use it to do "divide and rule" . And Distributed computing is where you actually do the same work divided across many machines. For example, if you would do a transaction and if it spans across many machines and when you would commit, if all would say that they are okay with what you have done, it's Distributed computing. Just many computers are there in both doesn't make them same.
3) There is no end to this thing I guess. We are in an environment where needs, demands are growing constantly. There is no such thing that what is large, fast anymore. What you call a supercompyter today, tomorrow it may work as a normal machine. Things are becoming faster, smaller and the thirst for more is just growing . I don't think that it's something that you should be bothered much about. In the last 20years or so, there is a constant evolution happening in technology and I can't think myself where this would end and what will be the final outcome of this rat-race of "faster, larger" .
Hope it does makes some sense and helps you.
Aman....