© 2000 copyright hewlett packard co. ha cluster superdome configurations john foxcroft,...
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© 2000 Copyright Hewlett Packard Co.
HA Cluster SuperDome Configurations
John Foxcroft, BCC/Availability Clusters Solutions Lab
HA Products Support Planning and Training
Version 1.0 9/22/00
2 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA Cluster SuperDome Configurations
• HA Cluster Review– HA Cluster Architectures– Cluster Quorum– Cluster Lock– Power Requirements– Disaster Tolerant Solutions
• Single Cabinet Configuration• Multi Cabinet Configurations• Mixed Server Configurations• Disaster Tolerant Solutions with SuperDome• References• FAQ’s• Lab Exercises
3 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
Range of HA Cluster ArchitecturesF
lexi
bil
ity
&F
un
ctio
nal
ity
Distance
Local Cluster
Campus Cluster
Metro Cluster
Continental Clusters
•Single Cluster•Automatic Failover•Same data center
•Single Cluster•Automatic Failover•Same Site
•Single Cluster•Automatic Failover•Same City
•Separate Clusters•“Push-Button” Failover•Between Cities
SuperDome is fully supported across all HA Cluster Architectures !
4 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
• MC/ServiceGuard Features: • Multi OS• One-stop GUI• Rolling upgrade• Tape sharing• 16 nodes• No idle system• Online reconfiguration• Automatic Failback• Rotating standby
• Closely integrated with OS, HP-UX
MC/ServiceGuard
Clients
Application Tier
Database Tier
5 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
1 2 3 4
1 2 3 4
2 3 4
100% quorum to boot unless using the manual override -f of cmruncl4 nodes
3 left out of 4 > 50% quorum(no lock required)
2 left of 3 > 50% quorum
3 4
1 left of 2 = 50% quorumCluster Lock needed to form cluster
Examples of Failures and Dynamic Quorum
6 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
1 2 3 4
1 2 3 4 5
2 left out of 4 = 50% quorumCluster Lock needed to form cluster
3 left out of 5 > 50% quorum(no lock required)
Examples of Failures and Dynamic Quorum
1 2 3 4 5
2 left out of 5 < 50% quorumCluster goes down !
7 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
Cluster Lock Disk
• A Cluster Lock Disk is required in a 2 node cluster (recommended for 3,4 nodes) to provide a tie breaker for the cluster after a failure.
• Cluster Lock Disk is supported for up to 4 nodes maximum.• Must be a disk that is connected to all nodes• Is a normal data disk, lock functionality only used after a node
failure
A A
B B
Cluster Lock
8 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
• Care should be taken to make sure a single power supply failure does not take out:– Half the nodes and– Cluster lock disk
Secure Power Supply
A A
A’ A’
Cluster Lock
9 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA SuperDome Configurations Remarks/Assumptions
• Each partition is equivalent to a traditional standalone server running and OS
• Each partition comes equipped with:– core I/O, other I/O and LAN connections
• Each partition connects to:– boot devices, data disks, removable media (DVD-ROM and/or DAT)
• Redundant components exist in each partition as an attempt to remove SPOFs (single-points-of-failure)– redundant I/O interfaces (disk and LAN)– redundant heartbeat LANs– boot devices protected via mirroring (MirrorDisk/UX or RAID)– critical data protected via mirroring (MirrorDisk/UX or RAID)– LAN protection
– auto-port aggregation for Ethernet LANs– MC/SG for Ethernet & FDDI– Hyperfabic and ATM provide their own LAN failover abilities
10 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA SuperDome Configurations Remarks/Assumptions
• Any partition that is protected by MC/SG can be configured in a cluster with: – a standalone system – another partition within the same SuperDome cabinet
(see HA considerations for more details). – another SuperDome
• Any partition that is protected by MC/SG contains as many redundant components as possible to further reduce the chance of failure. For example: – Dual AC power to a cabinet is recommended, if possible– Redundant I/O chassis attached to a different cell is
recommended, if possible
11 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA SuperDome Configurations Cabinet Considerations
• 3 Single Points of Failure (SPOF) have been identified within single cabinet 16-Way and 32-Way systems and dual cabinet 64-Way systems: – system clock, power monitor. system backplane
• To configure an HA cluster with no SPOF, the membership must extend beyond a single cabinet:– must be configured such that the failure of a single cabinet does not result in
the failure of a majority of the nodes in the cluster.– cluster lock device must be powered independently of the cabinets containing
the cluster nodes.
• Some customers want a “cluster in a box” configuration.– MC/ServiceGuard will support this configuration, however it needs to be
recognized that it does contain SPOFs that will bring down the entire cluster.– Mixed OS and ServiceGuard revisions should only exist temporarily while
performing a rolling upgrade within a cluster.
• 64-Way dual cabinet systems connected with flex cables have worse SPOF characteristics than single cabinet 16-Way and 32-Way systems. – There is no HA advantage to configure a cluster within a 64-Way system vs.
across two 16 or 32-Way systems.
• Optional AC input power on a separate circuit is recommended
12 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA SuperDome Configurations I/O Considerations
• Cluster heartbeat will be done over LAN connections between SuperDome partitions.
• Redundant heartbeat paths are required and can be accomplished by using either multiple heartbeat subnets or via standby interface cards.
• Redundant heartbeat paths should be configured in separate I/O modules (I/O card cages) when possible.
• Redundant paths to storage devices used by the cluster are required and can be accomplished using either disk mirroring or via LVM’s pvlinks.
• Redundant storage device paths should be configured in separate I/O modules (I/O card cages) when possible.
13 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA SuperDome Configurations Redundant I/O Paths Example
* Redundant paths are required for shared storage devices in a cluster* MirrorDisk/UX or PV-Links can be configured to provide alternate paths to to disk volumes and protect against I/O card failure (Logical Volume Manager feature)* At least two I/O card cages per partition are recommended to protect against I/O Card Cage failure
I/O Card Cage 1
1 FW SCSI CardCore I/O Card
12 Slots Total
I/O Card Cage 2
1 FW SCSI Card
12 Slots Total
D ISK
D ISK
D ISK
D ISKD ISK
D ISK
D ISK
D ISKP1
P2
F1 F2
Primary Path
Mirror/Alternate Path
1 Copy of HP-UXrunning inthis partition
Partition 1I/O Card Cage 1
1 FW SCSI CardCore I/O Card
12 Slots Total
I/O Card Cage 2
1 FW SCSI Card
12 Slots Total
Partition 2
Cell
Cell
Cell
Cell
1 Copy of HP-UXrunning inthis partition
14 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA Single Cabinet Configuration “Cluster in a Box”
Part
itio
n 1
Cell
Part
itio
n 2
Tw
o n
od
e S
erv
iceG
uard
C
lust
er
Notes:•Considered a "Single System" HA solution•SPOFs in the cabinet can cause the entire cluster to fail
(SPOF’s: clock, backplane, power monitor).•A four node (four partition) cluster is supported within a 16-Way system (*).•Up to a eight node (eight partition) cluster is supported within a 32-Way system (*).•Up to a sixteen node (sixteen partition) cluster is supported within a 64-Way system (*)•Cluster lock required for two partition configurations•Cluster lock must be powered independently of the cabinet.•N+1 power supplies required (included in base price of SD)•Dual power connected to independent power circuits required•Root volume mirrors must be on separate power circuits.
One 16W, 32W or 64W System
Cell
Cell
Cell
Cluster Lock
15 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA Multi Cabinet Configuration
Part
itio
n 1
Part
itio
n
2
Part
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n 1
Part
itio
n
2
Part
itio
n
3 Part
itio
n
3
Notes:•No SPOF configuration.•Cluster lock is required if cluster is wholly contained within two 16-Way or 32-Way systems (due to possible 50% cluster membership failure).•ServiceGuard only supports cluster lock up to four nodes, thus two cabinet solution is limited to four nodes.•Two cabinet configurations, must evenly divide nodes between the cabinets (i.e.. 3 and 1 is not a legal 4 node configuration).•Cluster lock must be powered independently of either cabinet•N+1 power supplies required•Dual power connected to independent power circuits required.•Root volume mirrors must be on separate power circuits
Oth
er
independ
ent
nodes
Two Independent 16-Way or 32-Way Systems
Cell
Cell
Cell
Cell
Cell
Cell
Cell
Cell
Cluster Lock
Tw
o n
ode S
erv
iceG
uard
clu
ster
16 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
Part
itio
n 1
Cell Cluster Lock
Cell
Cell
Cell
Part
itio
n 2
Cell
Cell
Cell
Cell
Part
itio
n 2
Part
itio
n 1
HA Multi Cabinet Configuration
Part
itio
n 1
Notes:•No SPOF configuration.•Cluster lock is required if a cluster is wholly contained within two 16-Way or 32-Way systems (due to possible 50% cluster membership failure).•ServiceGuard only supports cluster lock up to four nodes, thus two cabinet solution is limited to four nodes.•Two cabinet configurations, must evenly divide nodes between the cabinets (i.e.. 3 and 1 is not a legal 4 node configuration).•Cluster lock must be powered independently of either cabinet•N+1 power supplies required•Dual power connected to independent power circuits required.•Root volume mirrors must be on separate power circuits
Two Independent 32-Way SystemsTwo 4-node clusters
Cell Cluster Lock
Four
node S
erv
iceG
uard
cl
ust
er
Cell
Cell
Cell
Part
itio
n 2
Cell
Cell
Cell
Cell
Part
itio
n 2
Part
itio
n 1
Four
node S
erv
iceG
uard
cl
ust
er
17 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA Multi Cabinet Configuration64-Way System
64-Way System (dual cabinet)
4 CPUs8 GB RAM
4 CPUs8 GB RAM
4 CPUs8 GB RAM
4 CPUs8 GB RAM
Part
itio
n
1
4 CPUs8 GB RAM
4 CPUs8 GB RAM
4 CPUs8 GB RAM
4 CPUs8 GB RAM
4 CPU
8 GB RAM
4 CPUs8 GB RAM
Part
itio
n 2
4 CPU8 GB RAM
4 CPUs8 GB RAM
4 CPU
8 GB RAM
4 CPUs8 GB RAM
Part
itio
n 3
4 CPU8 GB RAM
4 CPUs8 GB RAM
64-Way System (dual cabinet)
4 CPUs8 GB RAM
4 CPUs8 GB RAM
4 CPUs8 GB RAM
4 CPUs8 GB RAM
Part
itio
n
1
4 CPUs8 GB RAM
4 CPUs8 GB RAM
4 CPUs8 GB RAM
4 CPUs8 GB RAM
4 CPU
8 GB RAM
4 CPUs8 GB RAM
Part
itio
n 2
4 CPU8 GB RAM
4 CPUs8 GB RAM
4 CPU
8 GB RAM
4 CPUs8 GB RAM
Part
itio
n 3
4 CPU8 GB RAM
4 CPUs8 GB RAM
Cluster Lock
Two node ServiceGuard cluster
18 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA Mixed Configurations
Part
itio
n 1
Notes:•Cluster configuration can contain a mixture of SuperDome and non-SuperDome nodes.•Care must be taken to maintain an even or greater number of nodes outside of the SuperDome cabinet. •Using an even number of nodes within and outside of the Superdome requires a cluster lock (maximum cluster size of four nodes).•Cluster lock is not supported for clusters with greater than four nodes.•ServiceGuard supports up to 16 nodes•A cluster size of greater than four nodes requires more nodes to be outside the Superdome. •Without a cluster lock, beware of configurations where the failure of a SuperDome cabinet will cause the remain nodes to be 50% or less quorum - the cluster will fail !
16-Way, 32-Way or 64-Way System and other HP9000 servers
Cell
Cell
N-Class
N-ClassCluster Lock
Four node ServiceGuard clusterPart
itio
n 2
Cell
Cell
19 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA Mixed Configurations
Part
itio
n 1
Notes:•Cluster configuration can contain a mixture of SuperDome and non-SuperDome nodes.•Care must be taken to maintain an even or greater number of nodes outside of the SuperDome cabinet. •Using an even number of nodes within and outside of the Superdome requires a cluster lock (maximum cluster size of four nodes).•Cluster lock is not supported for clusters with greater than four nodes.•ServiceGuard supports up to 16 nodes•A cluster size of greater than four nodes requires more nodes to be outside the Superdome. •Without a cluster lock, beware of configurations where the failure of a SuperDome cabinet will cause the remain nodes to be 50% or less quorum - the cluster will fail !
16-Way, 32-Way or 64-Way System and other HP9000 servers
Cell
Cell
N-Class
N-Class
Five node ServiceGuard clusterPart
itio
n 2
Cell
CellN-Class
No Cluster Lock
20 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA Mixed ConfigurationsUsing a low end system as an arbitrator
Part
itio
n 1
Notes:•A cluster size of greater than four nodes requires more nodes to be outside the Superdome. •One option is to configure a low end system to act only as an arbitrator (providing >50% quorum outside the SuperDome).•Requires redundant heartbeat LANs.•System on separate power circuit.•The SMS (Support Management Station) A-class system could be used for this purpose.
•A180 •A400, A500 •External LAN connections only(Built-in 100/BT card not supported with ServiceGuard)
16-Way, 32-Way or 64-Way System and other HP9000 servers
Cell
Cell
N-Class
N-Class
Five node ServiceGuard clusterPart
itio
n 2
Cell
Cell
A-Class
No Cluster Lock
21 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HA Mixed Configurations
Part
itio
n 1
Notes:•Cluster configuration can contain a mixture of SuperDome and non-SuperDome nodes.•Care must be taken to maintain an even or greater number of nodes outside of the SuperDome cabinet. •Using an even number of nodes within and outside of the Superdome requires a cluster lock (maximum cluster size of four nodes).•Cluster lock is not supported for clusters with greater than four nodes.•ServiceGuard supports up to 16 nodes•A cluster size of greater than four nodes requires more nodes to be outside the Superdome. •Without a cluster lock, beware of configurations where the failure of a SuperDome cabinet will cause the remain nodes to be 50% or less quorum - the cluster will fail !
16-Way, 32-Way or 64-Way System and other HP9000 servers
Cell
Cell
N-Class
N-Class
Five node ServiceGuard clusterPart
itio
n 2
Cell
CellN-Class
No Cluster Lock
N-Class down for maintenance,SPOF (SD) causes 50% quorum,Cluster fails !
22 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
Frequently Asked Questions (FAQ's)Question: Can I configure a ServiceGuard cluster within a single SuperDome cabinet ?
Answer: Yes, it is supported to configure a cluster within a single cabinet (16W, 32W or 64W). Recognize that this configuration contain SPOF’s that can bring down the entire cluster.
Question: In a two cabinet configuration (using 16W, 32W or 64W systems), can I configure 1 node in one cabinet and 3 nodes in the other ?
Answer: No, there are only two valid ways to create a cluster between two SuperDome systems; a 2 node cluster (1 node in one cabinet, 1 node in the other), or a 4 node cluster (2 nodes in one cabinet, 2 nodes in the other).
Question: Is a lock disk required for a 4 node (two cabinet) configuration ?
Answer: Yes, since a single failure can take down exactly half of the cluster nodes.
Question: Are dual power cables recommended in each cabinet ?
Answer: Yes, this optional feature should be ordered in HA configurations
Question: Can a cluster be four 32W systems each with one partition of 8 cells wide ?
Answer: Yes, single partition SuperDome systems (and non-SuperDome nodes) could be configured in up to a 16 node cluster.
Question: Are SuperDomes supported in Campus/Metro Cluster and ContinentalCluster configurations ?
Answer: Yes, subject to the rules covered in this presentation.
Question: Is heartbeat handled any differently between partitions within SuperDome boxes ?
Answer: Heartbeat is done over LAN connections between partitions. From the ServiceGuard perspective, each partition is just another HP-UX node.
23 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
References
ACSL Product Support information (patches, PSP, etc.)see http://haweb.cup.hp.com/Support, or Kmine
MC/ServiceGuard Users Manual Designing Disaster Tolerant HA Clusters Users Manual
see http://docs.hp.com/hpux/ha
XP256 Documentation see http://docs.hp.com/hpux/systems/#massstorage
HPWorld ‘99 Tutorial: “Disaster-Tolerant, Highly Available Cluster Architectures”see http://docs.hp.com/hpux/ha or
http://haweb.cup.hp.com/ATC/WP
25 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
• MC/ServiceGuard Features: • Multi OS• One-stop GUI• Rolling upgrade• Tape sharing• 16 nodes• No idle system• Online reconfiguration• Automatic Failback• Rotating standby
• Closely integrated with OS, HP-UX
MC/ServiceGuard
Clients
Application Tier
Database Tier
26 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
• ServiceGuard OPS Edition Features:
• Same protection functionality for applications as MC/SG
• Additional protection for Oracle database
• Parallel database environment for increased availability and scalability
ServiceGuard OPS Edition
End-User Clients
27 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
ServiceGuard Comparative Features
Cluster Topology Single Cluster up to 16 nodes (MC/ServiceGuard)Single Cluster up to 8 nodes (ServiceGuard OPS Edition)
Geography Data Center
Network Subnets Single IP Subnet
Network Types Dedicated Ethernet, FDDI or Token Ring
Cluster Lock Disk Required for 2 nodes, optional for 3-4 nodes, not used with largerclusters
Failover Type Automatic
Failover Direction Omni-directional
Data Replication NONE
28 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
Campus Cluster Solution =MC/SG + Fibre Channel
FC Hub
FC Hub
FC Hub
FC Hub
~10km
Heartbeat
Fibre Channel
29 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
Campus Cluster Comparative Features
Cluster Topology Single Cluster up to 4 nodes across 2 data centers orup to 16 nodes across 3 data centers
Geography Campus, up to 10 km (Fibre Channel limitations)
Network Subnets Single IP Subnet
Network Types Dedicated Ethernet, FDDI or Token Ring
Cluster Lock Disk Required for 2 nodes, optional for 3-4 nodes, notused with larger clusters
Failover Type Automatic
Failover Direction Bi-directional
Data Replication MirrorDisk/UX
30 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
MetroCluster with Continuous Access XP
HP Continuous Access XP
ManhattanManhattan New Jersey
HP SureStore E Disk Arrays
HP 9000 Systems
Delivering city-wide automated fail-over
Protect against Tornadoes, Fires, Floods
Rapid, automatic site recovery without human intervention
Effective between systems that are up to 43km apart
Provides very high cluster performance
Backed by collaborative implementation, training and support services from HP
Also available: MetroCluster with EMC SRDF, using EMC Symmetrix Disk Arrays
31 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
MetroCluster Comparative Features
Cluster Topology Single Cluster up to 16 nodes spread across 3 datacenters
Geography Campus or Metropolitan area
Network Subnets Single IP Subnet
Network Types Dedicated Ethernet, or FDDI
Cluster Lock Disk Not Used; 1-2 Arbitrators in third data center act astie breaker
Failover Type Automatic
Failover Direction Bi-directional
Data Replication Physical, in hardware (XP256 CA or EMC SRDF)
32 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
HP ContinentalClusters
Highest levels of availability & disaster tolerance
Reduces downtime from days to minutes Locate data centers at economically and/or
strategically best locations Transparent to applications and data
DataReplication
ClusterDetection
Push button failover across 1000s of km Supports numerous wide area data replication tools for
complete data protection Comprehensive Support and Consulting Services as
well as Business Recovery Services for planning, design, support, and rehearsal
Requires CSS support or greater
33 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
ContinentalClusters: Comparative Features
Cluster Topology Two Clusters, each up to 16 nodes
Geography Continental or Inter-continental
Network Subnets Dual IP Subnets
Network Types Dedicated Ethernet or FDDI within each data center,Wide Area Network (WAN) between data centers
Cluster Lock Disk Required for 2 nodes, optional for 3-4 nodes, notused with larger clusters
Failover Type Semi-Automatic
Failover Direction Uni-directional
Data Replication Physical, in hardware (XP256 CA or EMC SRDF)Logical in software (Oracle Standby Database, etc.)
34 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
Two Data Center Campus ClusterArchitecture (# 1)
Highly Available Network
Example: 4-node campus cluster using 16-way, 32-way or 64-way systems and fibre channel for disk connectivity (500 meters point-to-point, 10 kilometers using long wave ports with FCAL hubs)
Recommend multi cabinet SuperDome configurations at each data center for increased availability Each data center must contain the same number of nodes (partitions) Use of MirrorDisk/UX is required to mirror data between the data centers All systems are connected to both mirror copies of data for packages they can run All systems must be connected to the redundant heartbeat network links MUST have dual cluster lock disks, with all systems connected to both of them MAXIMUM cluster size is currently 4 nodes when using cluster lock disks
Data Center A
NW
NW
A A
B B
CL 1
Data Center B
NW
NW
A' A'
B' B'
CL 2
Physical Data Replicationusing MirrorDisk/UX
Physical Data Replicationusing MirrorDisk/UX
Part
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Part
itio
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2Cell
Cell
Cell
SuperDome SuperDome
Cell
Part
itio
n 1
Part
itio
n
2
Cell
Cell
Cell
Cell
35 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
Three Data Center Campus Architecture (#2)
Data Center A
NW
NW
A A
B B
Data Center B
NW
NW
A' A'
B' B'
Physical Data Replicationusing MirrorDisk/UX
SuperDome SuperDome
Data Center C
NWNW
1 or 2 Arbitrator System(s)
Physical Data Replicationwith MirrorDisk/UX
Maximum cluster size - 16 nodes with HP-UX 11.0 and later 11.x versions
Recommend multi cabinet SuperDome configurations at each data center for increased availability
Same number of nodes in each non-Arbitrator data center to maintain quorum in case an entire data center fails
Arbitrators need not beconnected to the replicated data
No Cluster Lock Disk(s) All non-Arbitrator systems must
be connected to both replicacopies of the data
All systems must be connectedto the redundant heartbeatnetwork links
Highly Available NetworkPart
itio
n 1
Part
itio
n
2Cell
Cell
Cell
Cell
Part
itio
n 1
Part
itio
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2
Cell
Cell
Cell
Cell
36 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
Three Data Center MetroCluster Architecture
Data Center A
NW
NW
Data Center B
NW
NW
SuperDome SuperDome
Data Center C
NWNW
1 or 2 Arbitrator System(s)
Highly Available Network
Physical Data Replicationwith EMC SRDF or XP256 CA
Physical Data Replicationwith EMC SRDF or XP256 CA
Arbitrators need not beconnected to the replicated data
No Cluster Lock Disk(s) Systems are not connected
to both replica copies of the data(cannot have two distinct devicesaccessible with the same VGID)
All systems must be connectedto the redundant heartbeatnetwork links
Maximum cluster size - 16 nodes with HP-UX 11.0 and later 11.x versions
Recommend multi cabinet SuperDome configuration at each data center for increased availability
Same number of nodes in each non-Arbitrator data center to maintain quorum in case an entire data center fails
Part
itio
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Part
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2Cell
Cell
Cell
Cell
Part
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Part
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2
Cell
Cell
Cell
Cell
37 © 2000 Hewlett-Packard Co.
SUPERDOME HA Clusters
Two Data Center ContinentalClusters Architecture
Systems are not connected to both replica copies of the data (hosts in each cluster are connected to only one copy of the data)
Each cluster must separately conform to heartbeat network requirements
Each cluster must separately conform to quorum rules (cluster lock disks or Arbitrators)
Primary Cluster Recovery ClusterHighly Available Wide Area
Network (WAN)
Physical or Logical Data Replication
Physical or Logical Data Replication
NW
NWNW
NW
Recommend multi cabinet SuperDome configuration at each data center for increased availability
Use of cluster lock disks requires three power circuits in each cluster
HA WAN is used for both data replication and inter-cluster monitoring
Data Center A Data Center B
SuperDomePart
itio
n 1
Part
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1
Cell
Cell
Cell
Cell
SuperDome
SuperDome
Part
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Part
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1
Cell
Cell
Cell
Cell
SuperDome