BYTUSHAR KANTI ROUTHDEPT->C.S.E 4TH YEAR7TH SEMISTER ROLL- [L-63 ] : BYTUSHAR KANTI ROUTHDEPT->C.S.E 4TH YEAR7TH SEMISTER ROLL- [L-63 ] Presentation
on cluster computing Introduction: : Introduction: Clustering is the use of multiple computers, storage devices , and redundant interconnections , to form what appears to users as a singly highly available system .
Computer cluster technology puts clusters of systems together to provide better system reliability and performance .
“ A cluster is a type of parallel or distributed processing system , which consists of a collection of interconnected stand alone computers cooperatively working together as a single integrated computing resource . ,, A SIMPLE CLUSTER LAY OUT:- : A SIMPLE CLUSTER LAY OUT:- Slide 4: Classifications
Cluster Computer Clusters Classification..1 : Clusters Classification..1 This type of Cluster classification based on application Target , and again classified intotwo subcategories :
High Performance (HP) Clusters
Grand Challenging Applications
High Availability (HA) Clusters
Mission Critical applications HA Cluster: Server Cluster with "Heartbeat" Connection : HA Cluster: Server Cluster with "Heartbeat" Connection Clusters Classification..2 : Clusters Classification..2 This type Clusters classification based on Node Ownership are again classified into two subcategories : -
Adaptive parallel computing
Also called Communal multiprocessing Clusters Classification..3 : Clusters Classification..3 This type of classification based on Node Architecture..
Clusters of PCs ( CoPs)
Clusters of Workstations ( COWs)
Clusters of SMPs ( CLUMPs) Clusters Classification..4 : Clusters Classification..4 This type of classification based on node OS Type..
Linux Clusters (Beowulf)
Solaris Clusters (Berkeley NOW)
NT Clusters (HPVM)
AIX Clusters (IBM SP2)
SCO/Compaq Clusters (Unixware)
…….Digital VMS Clusters, HP clusters, ……………….. Clusters Classification..5 : Clusters Classification..5 This type of classification based on node components architecture & configuration (Processor Arch, Node Type PC/Workstation.. & OS: Linux/NT..):-
All nodes will have similar configuration
Nodes based on different processors and running different OS es. Clustering methods:- : Clustering methods:- Clustering method can be divided into two types:-
A) Hierarchical method.
B) Partition method .
A) Hierarchical method: -
This method proceed successively by either merging smaller clusters into larger ones, or by splitting larger clusters. The clustering methods differ in the rule by which it is decided which two small clusters are merged or which large cluster is split. The end result of the algorithm is a tree of clusters called a dendrogram, which shows how the clusters are related. By cutting the dendrogram at a desired level a clustering of the data items into disjoint groups is obtained. Slide 12: B) Partitional method :-
This method attempts to directly decompose the data set into a set of disjoint clusters. The criterion function that the clustering algorithm tries to minimize may emphasize the local structure of the data, as by assigning clusters . Clustering algorithms : : Clustering algorithms : Clustering algorithm may be classified into as listed below :-
Probabilistic Clustering Now among the several clustering algorithm ,The most popular and very usable clustering algorithms are:- : Now among the several clustering algorithm ,The most popular and very usable clustering algorithms are:- Fuzzy C-means .
Hierarchical clustering .
Mixture of Gaussians .
Each of these algorithms belongs to one of the clustering types on previous slide.
Such that , K-means is an exclusive clustering algorithm.
Fuzzy C-means is an overlapping clustering algorithm.
Hierarchical clustering is obvious and lastly Mixture of Gaussian is a probabilistic clustering algorithm. Now we discuss most popular algorithm K-means algorithm . : Now we discuss most popular algorithm K-means algorithm . K means algorithm will do the three steps :-
Iterate until stable (= no object move group):
Determine the centroid coordinate
Determine the distance of each object to the centroids
Group the object based on minimum distance K-mean algorithm : K-mean algorithm Decide on a value for K, the number of clusters.
Initialize the K cluster centers (randomly, if
Decide the class memberships of the N objects by
assigning them to the nearest cluster center.
Re-estimate the K cluster centers, by assuming the
memberships found above are correct.
Repeat 3 and 4 until none of the N objects changed
membership in the last iteration Comments on k-mean algorithm : Comments on k-mean algorithm • Strength
– Simple, easy to implement and debug
– Intuitive objective function: optimizes intra-cluster similarity
– Relatively efficient: O(tkn), where n is # objects, k is # clusters,
and t is # iterations. Normally, k, t << n.
– Applicable only when mean is defined, then what about
– Often terminates at a local optimum. Initialization is important.
– Need to specify K, the number of clusters, in advance
– Unable to handle noisy data and outliers
– Not suitable to discover clusters with non-convex shapes
– Assign members based on current centers
– Re-estimate centers based on current assignment Architectures of a cluster : Architectures of a cluster Architectures of a cluster:- : Architectures of a cluster:- The main component to design a cluster architectures is :-
[ 1 ] – multiple stand alone computers
( such as pcs , workstation , smps )
[ 2 ] – operating system ( linux )
[ 3 ] – a high performancs interconnect
[ 4 ] – communication softwear
[ 5 ] - cluster middlewear
[ 6 ] - different application platform
( parallel application , sequential application ) COMPONENTS OF CLUSTER COMPUTER : COMPONENTS OF CLUSTER COMPUTER The cluster consists of four major parts. These parts are:
2) Compute nodes,
3) Master server,
Each part has a specific function that is needed for the hardware to perform its function.
Provides communication between nodes, server, and gateway
Consists of fast Ethernet switch, cables, and other networking hardware
Serve as processors for the cluster
Each node is interchangeable, there are no functionality differences between nodes
Consists of all computers in the cluster other than the gateway and server 5. Slide 21: 3 Server:
Provides network services to the cluster
NFS (Node image and shared file system)
Actually runs parallel programs and spawns processes on
Should have minimum requirement.
Acts as a bridge/firewall between outside world and cluster
Should have two ethernet card Why is it required? : Why is it required? Clusters are surprisingly powerful .super computers are really expensive , and maintains cost is too high , but clusters are cheaper and much faster than super computer . In some area of researches cluster are actually faster then commercial super computer .Sometime we don’t even have to use new equipment to build a cluster . Application :- : Application :- Scientific computing
Comercial server ( web/datbase etc) Advantage on cluster computing : Advantage on cluster computing Size Scalability (physical & application)
Enhanced Availability (failure management)
Single System Image (look-and-feel of one system)
Fast Communication (networks & protocols)
Load Balancing (CPU, Net, Memory, Disk)
Security and Encryption (clusters of clusters)
Distributed Environment (Social issues)
Manageability (admin. And control)
Programmability (simple API if required)
Applicability (cluster-aware and non-aware app.) Disadvantage on cluster computing : Disadvantage on cluster computing Can be heard to manage with out experience
finding out where something has failed increases at least linearly as cluster size
programming environment could be vastly improve
when software configuration on some node is different then on others node conclusion:- : conclusion:- Clusters are promising Solve parallel processing paradox
Offer incremental growth and matches with funding pattern
New trends in hardware and software technologies are likely to make
clusters more promising and fill SSI gap.
Clusters based supercomputers (Linux based clusters) can be seen
everywhere! References : References www.buyya. comwww.beowulf .orgwww.clustercomp. orgwww.sgi. comwww .thu. edu
www. dgs. monash.edu.
www.webopedia. comwww.howstuffworks. com