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?
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
What are Windows Clusters?
1. Network Load Balancing 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
What are Windows Clusters?
1. Network Load Balancing Clusters
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
What are Windows Clusters?
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
What are Windows Clusters?
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
What are Windows Clusters?
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
What are Windows Clusters?
3. Server Clusters (Continued…)
Server Clusters Example Diagram [1]
Microsoft Cluster Service
MSCS (Microsoft Cluster Service)
• First shipped with Windows NT Server Enterprise Edition
(1997)
• Later upgraded in Windows 2000 Advanced Server and
Windows Server 2003
Microsoft Cluster Service
MSCS Terminology
• Node
• Resource
• Group
• Quorum resource
• Virtual Server
• Heartbeats
Microsoft Cluster Service
Windows NT Clusters
• Cannot have more than two nodes
Nodes, groups, and resources
Microsoft Cluster Service
Win 2000 Vs Win 2003 MSCS
• 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
Microsoft Cluster Service
How do MSCS work?
MSCS deals with:
• Cluster membership activities
• Resource management (and failure handling)
• Application state failover
• Cluster management
Microsoft Cluster Service
Cluster Membership
Start Cluster
Offline
Initializing
Service Fails
Cluster Service
Started
Search Fails
Sleeping
Complete
Rundown
Retries
Exceeded
Timeout
Member
Search
Search Fails
Quorum
Disk Search
Found
Online
Member
Exiting
Quorum
Disk
Found
Join Fails
Forming
Joining
Join
Succeeds
Paused
Pause
Evict or Leave
Cluster
Shutdown System
Stop Cluster Service
Key:
Resume
Synchronize
Succeeds
Online
- Externally visibile state
- Internal state
State transition diagram for cluster membership
Microsoft Cluster Service
Resource Management
• Resource Control Libraries map to different resources
• A resource can be:
– Offline
– Online pending
– Online
– Offline pending
– Failed
• Failed resources are recovered
Microsoft Cluster Service
MSCS Supported Applications
•
Microsoft SQL Server
•
Oracle Database Server
•
SAP R/3
•
Microsoft Exchange
•
Microsoft Internet Security
But not many more!
Windows Vs. Other Systems
Windows provides support for High
Availability (HA):
• Network load balancing
• Failover and redundancy
But there is another kind of clustering . . .
Windows Vs. Other Systems
High Performance Computing
Currently Windows has no built-in support for this.
Several different cluster models exist:
• Beowulf
• Single System Image
Windows Vs. Other Systems
Beowulf Clusters
“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/
Windows Vs. Other Systems
Beowulf Clusters (Continued…)
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.
Windows Vs. Other Systems
Single-System Image Clusters
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
Windows Vs. Other Systems
Windows HPC
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/
Research Directions
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 MPI2 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
1. High-Performance Computing: WMPI
II(Cont)
• 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
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
2. TerraServers (Cluster-SAN)
• 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
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
TerraServer Brick architecture
Research Directions
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.
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