Clustering & Fibre ChannelClustering & Fibre ChannelNext wave in PC Computing

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Trends in ClusteringTrends in Clustering Today clusters are a niche Unix market. But, Microsoft will bring

clusters to the masses

Microsoft has announced NT clusters SCO has announced UnixWare clusters Sun has announced Solaris / Intel clusters Novell has announced Wolf Mountain clusters

In 1998, 2M Intel servers will ship 100K in clusters

In 2001, 3M Intel servers will ship 1M in clusters (IDC’s forecast)

Clusters will be a huge market and RAID is essential to clusters

Fibre Channel and storage area networks are ideal for use in clusters.

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Why is the IT Market Moving Why is the IT Market Moving To ClusteringTo Clustering

Growth In On-Line Applications E-Commence On-Line Transaction Processing Web Servers Real Time Manufacturing

Server Must Be On Line 24 Hours a Day, 7 Days A Week, 365 Days a Year New Levels Of Fault Tolerance

Performance Must Scale

“Without Our Data, Our Business Is Dead”

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What Are Clusters?What Are Clusters?

Group of independent servers whichFunction as a single systemAppear to users as a single systemAnd are managed as a single system

Clusters are “virtual servers”

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Clusters Improve System Availability

Clusters Enable Application Scaling

Clusters Simplify System Management

Clusters Are A Superior Server Solution

Why Are Clusters Important?Why Are Clusters Important?

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When a networked server fails, the service it provided is down.

When a clustered server fails, the service it provided “failover” and downtime is avoided.

MailServer

InternetServer

Networked Servers

Clustered Servers

Mail & Internet

Clusters Improve System Clusters Improve System AvailabilityAvailability

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Clusters Enable Application Clusters Enable Application ScalingScaling

With networked SMP servers, application scaling is limited to a single server

With clusters, applications scale across multiple SMP servers (typically up to 16 servers)

E-Mail Voice mail

OracleVoice mail

OracleE-Mail

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Clusters Simplify System ManagementClusters Simplify System Management

Clusters present a Single System Image; the cluster looks like a single server to management applications

Hence, clusters reduce system management costs

Three Management Domains

One Management Domain

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An Analogy to RAIDAn Analogy to RAID RAID Makes Disks Fault Tolerant

Clusters make servers fault tolerant

RAID Increases I/O Performance Clusters increase compute performance

RAID (GAM) Makes Disks Easier to Manage Clusters make servers easier to manage

RAID

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Two Flavors of ClustersTwo Flavors of Clusters

High Availability Clusters Microsoft's Wolfpack 1 Compaq’s Recovery Server

Load Balancing Clusters(a.k.a. Parallel Application Clusters) Microsoft’s Wolfpack 2 Digital’s VAXClusters

Note: Load balancing clusters are a superset of high availability clusters.

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Available Clustering Available Clustering SoftwareSoftware

Failover Clusters Microsoft Clustered Servers (Enterprise Server 4.0) Compaq’s Recovery Server NCR Lifekeeper Digital NT Clusters UnixWare 7 Reliant NSI DoubleTake failover in Wide Area Networks Novell’s Vinca Corp. Standby Server

Load Balancing Clusters Microsoft’s Clustered Servers (NT 5.0) Digital’s VAXClusters IBM’s HACMP Oracle’s Parallel Server Novell’s Orion

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Failover ExampleFailover Example

Two node clusters (node = server)

During normal operations, both servers do useful work

Failover When a node fails, applications “failover” to the surviving node and it

assumes the workload of both nodes

Mail Web

Mail & Web

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Load Balancing ExampleLoad Balancing Example

Failover (cont’d) Multi-node clusters (two or more nodes)

Load balancing clusters typically runs a single application, e.g. database, distributed across all nodes

Cluster capacity is increased by adding nodes (but like SMP servers, scaling is less than linear)

3,000 TPM 3,600 TPM

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Load Balancing Example Load Balancing Example (cont’d)

Cluster rebalance the workload when a node dies

If different apps are running on each server, they failover to the least busy server or as directed by preset failover policies

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Sharing Storage In Clusters Sharing Storage In Clusters

#1. “Shared Nothing” Model

Microsoft’s Wolfpack Cluster

#2. “Shared Disk” Model

VAXClusters

Two Models For StorageTwo Models For Storage

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What is Fibre Channel?What is Fibre Channel?

Fibre channel is a high performance multiple protocol data transfer technology. Fibre channels primary task is to transport data extremely fast with the least possible delay. Fibre channel is a serial interconnect standard that allows servers, storage devices, and workstation users to share large amounts of data quickly. Fibre channel gives networks superior data transfer speeds, flexible topology, and flexible upper-level protocols. Fibre channel easily handles both networking and peripheral I/O communication over a single channel.

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Key Features of Fibre Key Features of Fibre ChannelChannel

Data Transfer Rates up to 100 MB/sec per connection Three Fibre channel connection schemes

Point-to-Point: Provides a single connection between two servers or a server

and its RAID storage. Switched Fabric:

Using a Fibre channel switch this connection allows each server or RAID storage to be connected point-to-point to a switch. This method allows for the construction of massive data storage and server networks.

Loop: Connects up to 126 servers, RAID systems, or other storage

devices in a loop topology.

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Key Features of Fibre Key Features of Fibre ChannelChannel

Long Distance Connections: Up to 10 kilometers

High reliability connections providing high data integrity Low Overhead Multiple media types support:

Copper: lower cost not as reliable as fibre optic cable distances up to 20 meters between nodes

Fibre optic: higher cost more reliable than copper distance up to 10,000 meters between nodes

Allows for creation of Storage Area Networks

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Benfits of Fibre ChannelBenfits of Fibre Channel

Runs multiple protocols over a single network or loop

Ideal solution for clustering of servers

Enables multiple servers to share storage and RAID systems

Scales from small numbers of peripherals attached short distances apart, to large numbers attached many kilometers apart.

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Benfits of Fibre Channel Benfits of Fibre Channel (cont’d)

Delivers speeds that are 2.5 to 250 times faster than existing communication and I/O interfaces

Overcomes today's network performance limitations regarding error detection and recovery

Provided low-cost and reliable performance for distance connections

Offers flexible protocols and topologies to best leverage existing technology investments

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Cluster InterconnectCluster Interconnect

This is about how servers are tied together and how disks are physically connected to the cluster.

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Clustered servers always have a client network interconnect, typically Ethernet, to talk to users, and at least on cluster interconnect to talk to other nodes and to disks.

Cluster InterconnectCluster Interconnect

Client Network

HBACluster Interconnect

HBA

RAID

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Or they can have Two Cluster Interconnects One for nodes to talk to each other:

Heartbeat Interconnect typically Ethernet And one for nodes to talk to disks

Shared Disk Interconnect typically SCSI or Fibre channel

Cluster InterconnectCluster Interconnect

NICCluster Interconnect

RAID

Shared Disk InterconnectHBA

NIC

HBA

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Each node has: Ethernet NIC -- Heartbeat Private system disks (HBA) PCI-based RAID controller - SCSI or Fibre, such as Mylex’s

eXtremeRAID™

Nodes share access to data disks but do not share data

NT Cluster with Host-Based RAID NT Cluster with Host-Based RAID ArrayArray

Shared Disk Interconnect

“Heartbeat” InterconnectHBA HBANICNIC

RAID RAID

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NT Cluster w/ SCSI External RAID ArrayNT Cluster w/ SCSI External RAID Array Each node has:

Ethernet NIC -- Heartbeat Multi-channel HBA’s connect boot disk and external array

Shared external RAID controller on the SCSI Shared Disk Interconnect

Shared Disk Interconnect

“Heartbeat” Interconnect

HBAHBA

NICNIC

RAID

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NT Cluster w/ Fibre External RAID ArrayNT Cluster w/ Fibre External RAID Array

Fibre Channel Host to Ultra2 SCSI LVD RAID system Fibre Channel Host to Fibre Channel RAID system

Shared Disk Interconnect

“Heartbeat” Interconnect

HBAHBA

NICNIC

RAID

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Internal vs External RAID in ClusteringInternal vs External RAID in Clustering

Internal RAID Lower cost solution Higher performance in read-intensive applications

Proven TPC-C performance enhances cluster performance External RAID

Higher performance in write-intensive application Write-back cache is turned-off in PCI-RAID controllers

Higher connectivity Attach more disk drives

Greater footprint flexibility Until PCI-RAID implements fibre

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Active / ActiveActive / Active

Fibre Channel Host - Ultra2 LVD RAID Controller in a Clustered Loop

HBAHBA

SXSX

Single FC Array Interconnect

FC HBA FC HBA

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SF (or FL) Active / Active DuplexSF (or FL) Active / Active Duplex

HBAHBA

Dual FC Array Interconnect

FC HBA FC HBA

FC Disk Interconnect

FC HBA FC HBA

SFSF

Fibre Channel Host - Ultra2 LVD RAID Controller in a Clustered Environment

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Fibre HostFibre Host

HBAHBA

Single FC Array Interconnect

FC HBA FC HBA

FFFF

Active / Active Duplex

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FC - FC in ClusterFC - FC in Cluster

HBAHBA

Dual FC Array Interconnect

FC HBA FC HBA

FC HBA FC HBA

FFFF

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Mylex - The RAID Clustering ExpertsMylex - The RAID Clustering Experts

eXtremeRAID™ 1100

AcceleRAID™ 250

DAC SF

DAC FL

DAC FF