windows clusters asma ounnas, bilel remmache, tom davis and toby weiss

Windows Clusters

Asma Ounnas, Bilel Remmache, Tom Davis and Toby Weiss

Introduction•What are Windows Clusters

•Network Load Balancing Clusters•Component Load Balancing Clusters•Server Clusters

•Microsoft Windows Clustering Services (MSCS)•NT, 2000 and 2003•Cluster Membership and Resource Management•Applications supporting MSCS

•Alternatives to Windows Clustering•High Performance computing

•Research Directions in Windows Clustering•High Performance Computing•TerraServers•Image Clustering

What are Windows Clusters?


A collection of Windows Servers working together.

Three clustering technologies exist:

1. Network Load Balancing Clusters

2. Component Load Balancing Clusters

3. Server Clusters


•The Network Load Balancing (NLB) service enhances the availability and scalability of Internet server applications

•These include: Web, FTP, firewall, proxy and VPN servers - any applications which communicate using the TCP/IP or UDP protocols

•Each host runs separate copies of the Web Server Application

•Client requests are distributed across hosts in a cluster

•If a host goes offline for any reason, requests are automatically redistributed amongst remaining hosts – providing redundancy

•For increased user capacity and fault tolerance, additional servers can be added at any time, allowing the Web applications to be distributed further


Two connected NLB Clusters – to interlink distributed Firewalls and Web Servers

Taken from: http://www.microsoft.com/resources/documentation/WindowsServ/2003/standard/proddocs/en-us/Default.asp?url=/resources/documentation/WindowsServ/2003/standard/proddocs/en-us/NLB_key_features.asp



2. Component Load Balancing Clusters

•This feature of Microsoft Application Center 2000 allows COM+ applications to be distributed across multiple servers

•The main purpose of this cluster type is for distributing servers for large web-site applications usually involving both a Web Tier (to provide web page layouts etc) and a Business Logic Tier (e.g. providing a connection to a database server)

•This provides:

Manageability – Single unified content management system, for content distributed across clusters, remote administration

Scalability – Easy to cope with changing throughput needs

Availability – No single point of failure – redundant web-sites


3. Server Clusters

•“A server cluster is a group of independent computer systems, known as nodes, working together as a single system to ensure that critical applications and resources remain available to clients”[1]

•They provide high-availability application support for distributed servers such as Database servers (such as MS SQL), Collaboration servers (such as Exchange) and Infrastructure servers (such as file and print servers)

•Every node may be attached to one or more cluster storage devices

•Clusters can be setup, configured and managed remotely using specialised Administrative software

[1]: Microsoft Windows Server System – Server cluster overview – 2004 – Available from the World Wide Web: http://www.microsoft.com/resources/documentation/WindowsServ/2003/standard/proddocs/en-us/Default.asp?url=/resources/documentation/WindowsServ/2003/standard/proddocs/en-us/cs_about_3jub.asp


3. Server Clusters (Continued…)

•Clustering software is used to control communication between nodes. It manages communication to control resource management and also controls cluster activity, communication between cluster nodes, and failure operations.

•Administrative Software allows configuration, control and monitoring of clusters and the nodes within them


Server Clusters Example Diagram [1]


3. Server Clusters (Continued…)

Microsoft Cluster Service

• First shipped with Windows NT Server Enterprise Edition (1997)

• Later upgraded in Windows 2000 Advanced Server and Windows Server 2003

MSCS (Microsoft Cluster Service)


• Node

• Resource

• Group

• Quorum resource

• Virtual Server

• Heartbeats

MSCS Terminology


• Cannot have more than two nodes

Nodes, groups, and resources

Windows NT Clusters

• Windows 2000 Server:– Advanced Server: 2 nodes– Datacenter Server: up to 4 nodes– Support for geographically dispersed nodes

• Windows 2003 Server:– Up to 8 nodes in both Advanced and Datacenter– Support for N+I configurations and 64-bit Processors– Majority Node Set


Win 2000 Vs Win 2003 MSCS

MSCS deals with:

• Cluster membership activities

• Resource management (and failure handling)

• Application state failover

• Cluster management

How do MSCS work?


State transition diagram for cluster membership

Offline

Start Cluster

Service FailsCluster Service

Started

MemberSearch

Joining

Paused

Online

Exiting

Sleeping

QuorumDisk Search

Forming

ResumePause

JoinSucceeds

Join Fails

FoundOnline

Member

Search Fails

Search Fails

Evict or LeaveCluster

Shutdown System Stop Cluster Service

SynchronizeSucceeds

Timeout

RetriesExceeded

CompleteRundown

QuorumDisk

Found

Initializing

Key:

- Externally visibile state

- Internal state

Cluster Membership


• Resource Control Libraries map to different resources

• A resource can be:

– Offline

– Online pending

– Online

– Offline pending

– Failed

• Failed resources are recovered

Resource Management


• Microsoft SQL Server

• Oracle Database Server

• SAP R/3

• Microsoft Exchange

• Microsoft Internet Security

But not many more!

MSCS Supported Applications


• Network load balancing• Failover and redundancy

But there is another kind of clustering . . .

Windows Vs. Other Systems

Windows provides support for High Availability (HA):

Currently Windows has no built-in support for this.

Several different cluster models exist:

• Beowulf

• Single System Image

High Performance Computing


“Beowulf Clusters are scalable performance clusters based on commodity hardware, on a private system network, with open source software (Linux) infrastructure.”

- http://www.beowulf.org/

Beowulf Clusters


http://www.beowulf.org/


How does they work?

• PVM (Parallel Virtual Machine)

– Allows network of computers to appear as one concurrent computational resource

• MPI (Message Passing Interface)

– Goal to develop a standard for message passing programs.

Beowulf Clusters (Continued…)


Single-system image (SSI) involves making a distributed

system appear as a single system to the user.

openMosix:

• Supports transparent migration of processes

• Software does not need to be rewritten to take

advantage of cluster

• Achieves automatic load balancing

Single-System Image Clusters


Although Microsoft do not provide direct Windows support

for HPC clusters:

• There is research going on into this

• Third parties provide their own MPI libraries for Windows

• Southampton HPC Centre:

http://www.windowsclusters.org/

Windows HPC

http://www.windowsclusters.org/

Research Directions

1. High-Performance Computing: WMPI II

2. TerraServers

3. Image Clustering:

• ImageSeer: Clustering and Searching WWW Images

• Locality Preserving Clustering for Image Database

Research Directions

1. High-Performance Computing:WMPI II

•Southampton HPC Centre

•Critical Software specialise in creating High Performance Computing (HPC) middleware.

•WMPI II™: is the high-end member of Critical Software's line of middleware products for HPC clusters providing a comprehensive MPI-2 standard implementation: version 2.0 of MPI-2.

•WMPI II is widely used in industrial applications: Computational Fluid Dynamics (CFD), Finite Element Analysis (FEA) and by academia for research and development programmes and for educational purposes.

•WMPI II is free to download and evaluate!

Research Directions

• Performance

• Reliability

• Thread safety

• Full MPI-2 standard compliance

• Support for 3rd party tools (debugger and profiler)

• Large Platform support (Windows platforms and Linux-distributions)

• Commitment for continues product evolution (to meet evolving market needs)

• Integration and embedded support (OEMs)

• Professional technical support

• Scalability, up to > 1000 processors without any architectural limitation

1. High-Performance Computing: WMPI II(Cont)

Research Directions

1. High-Performance Computing: WMPI II(Cont) 2

Research Directions

2. TerraServers

• Microsoft® TerraServer displays (stores) aerial, satellite, and topographic images of the earth in a SQL database available via the Internet, www.terraserver.microsoft.com

• One of the most popular online atlases: 22 terabytes of image data from the US Geological Survey (USGS).

• Initially deployed in 1998.• The system demonstrated the scalability of PC hardware and

software – Windows and SQL Server – on a single, mainframe-class processor.

• In September 2000, the back-end database application was migrated to 4-node active/passive cluster connected to an 18 terabyte Storage Area Network (SAN). The new configuration was designed to achieve 99.99% availability for the back-end application.

Research Directions

TerraServer Installation Photograph

Research Directions

• Storage Area Networks: simplified the wiring between nodes and disk resources and had good management tools => became the preferred processor-storage inter-connection mechanism

• 3 years of operation

• The hardware and software components of the TerraServer Cluster and SAN: reliable, easy to operate when no changes are needed

• Both high-traffic web server and a high traffic web service

2. TerraServers (Cluster-SAN)

Research Directions

• Windows Clusters

TerraServer SAN Cluster Block Diagram

Research Directions

2. TerraServers (Cont)

• TerraServer failed to achieve four nines of availability – 99.99%. The vast majority of the downtime was due to operations mistakes that could have been avoided with improved procedures.

• 2004: SAN cluster replaced with a duplexed set of “white-box” PCs containing arrays of large, low-cost, Serial ATA disks: TerraServer Bricks – A High Availability Cluster Alternative

• The goal is to operate the popular TerraServer web site with the same or higher availability than the TerraServer SAN at a fraction of the system and operations cost.

• Improving resolution to 0.5 m.

Research Directions

TerraServer Brick architecture

The TerraServer web site is composed of:

• A redundant farm of web bricks,

• A mirrored array of storage bricks,

• A redundant LAN linking the web and storage bricks,

• A remote IP keyboard video, mouse (KVM) switch,

• And, remote IP power distribution units (PDU).

Research Directions

Research Directions

TerraServer Brick architecture

3. Image Clustering

Image clustering is a technique that helps searching and browsing image repositories in several ways, including image data preprocessing, user interface designing, and search result representation.

1. ImageSeer: Clustering and Searching WWW Images

2. Locality Preserving Clustering for Image Database

Research Directions

3.1 ImageSeer system Microsoft Research Asia (Beijing, China) and DCS University of Chicago

• ImageSeer is a web image search engine:

• Using a vision based page segmentation algorithm, a web page is partitioned into blocks• The textual and link information of an image can be accurately extracted within the block containing that image• The textual information is used for image representation • By extracting the page-to-block, block-to-image, block-to-page relationships through link structure and page layout analysis, an image graph is constructed • With the graph models, techniques used from spectral graph theory and Markov Chain theory for image ranking, clustering and embedding

Research Directions

Figure 4. Design of WWW image search system

Research Directions

3.1 Locality Preserving Clustering for Image Database

Spectral clustering method has been one of the most promising clustering methods in the last few years, because it can cluster data with complex structure, and the (near) global optimum is guaranteed.

Existing spectral clustering algorithms: difficult to handle data points out of training set (Normalized Cut, direct Kmeans, PCA+Kmeans)

Locality Preserving Clustering (LPC): – Shares many of the data representation properties of nonlinear

spectral method– Provides an explicit mapping function which is defined

everywhere, both on training data points and testing points.

Research Directions

Windows Clusters

Summary•What are Windows Clusters

•Network Load Balancing Clusters•Component Load Balancing Clusters•Server Clusters

•Microsoft Windows Clustering Services (MSCS)•NT, 2000 and 2003•Cluster Membership and Resource Management•Applications supporting MSCS

•Alternatives to Windows Clustering•High Performance computing

•Research Directions in Windows Clustering•High Performance Computing•TerraServers•Image Clustering

Windows Clusters

windows clusters asma ounnas, bilel remmache, tom davis and toby weiss

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