User's Guide

Planning the Fabric
TCP / UDP / IP
Chapter 2
24
To create a highly available HyperFabric cluster, there cannot be any single point of
failure. Once the HP 9000 nodes and the HyperFabric hardware have been
configured with no single point of failure, ServiceGuard and EMS can be configured
to monitor and fail-over nodes and services using ServiceGuard packages.
If any HyperFabric resource in a cluster fails (adapter card, cable or switch port), the
HyperFabric driver transparently routes traffic over other available HyperFabric
resources with no disruption of service.
The ability of the HyperFabric driver to transparently fail-over traffic reduces the
complexity of configuring highly available clusters with ServiceGuard, because
ServiceGuard only has to take care of node and service failover.
A “heartbeat” is used by MC/ServiceGuard to monitor the cluster. The HyperFabric
links cannot be used for the heartbeat. Instead an alternate LAN connection
(Ethernet, Gigabit Ethernet, 10Gigabit Ethernet) must be made between the nodes
for use as a heartbeat link.
End To End HA: HyperFabric provides End to End HA on the entire cluster fabric
at the link level. If any of the available routes in the fabric fails, HyperFabric will
transparently redirect all the traffic to a functional route and, if configured, notify
ServiceGuard or other enterprise management tools.
Active-Active HA: In configurations where there are multiple routes between
nodes, the HyperFabric software will use a hashing function to determine which
particular adapter/route to send messages through. This is done on a
message-by-message basis. All of the available HyperFabric resources in the fabric
are used for communication.
In contrast to Active-Passive HA, where one set of resources is not utilized until
another set fails, Active-Active HA provides the best return on investment because
all of the resources are utilized simultaneously. MC/ServiceGuard is not required for
Active-Active HA operation.
For more information on setting up HA HyperFabric clusters, see figure 2-3
“TCP/UDP/IP High Availability Switched Configuration”.
• Dynamic Resource Utilization (DRU): Supported
When a new resource (node, adapter, cable or switch) is added to a cluster, a
HyperFabric subsystem will dynamically identify the added resource and start using
it. The same process takes place when a resource is removed from a cluster. The
difference between DRU and OLAR is that OLAR only applies to the addition or
replacement of adapter cards from nodes.
• Load Balancing: Supported
When a HP 9000 HyperFabric cluster is running TCP/UDP/IP applications, the
HyperFabric driver balances the load across all available resources in the cluster
including nodes, adapter cards, links, and multiple links between switches.
• Switch Management: Not Supported
Switch Management is not supported. Switch management will not operate properly
if it is enabled on a HyperFabric cluster.
• Diagnostics: Supported
Diagnostics can be run to obtain information on many of the HyperFabric
components via the clic_diag, clic_probe and clic_stat commands, as well as
the Support Tools Manager (STM).