HyperFabric Administrator's Guide (HP-UX 11i v1)

Planning the Fabric
Hyper Messaging Protocol (HMP)
Chapter 2 33
Within a cluster, ServiceGuard groups application services
(individual HP-UX processes) into packages. In the event of a single
service failure (node or network), EMS provides notification and
ServiceGuard transfers control of the package to another node in the
cluster, allowing services to remain available with minimal
interruption. ServiceGuard using EMS, directly monitors cluster
nodes, LAN interfaces, and services (the individual processes within
an application). ServiceGuard uses a heartbeat LAN to monitor the
nodes in a cluster. ServiceGuard cannot use the HyperFabric
interconnect as a heartbeat link. Instead, a separate LAN must be
used for the heartbeat.
For more information on configuring ServiceGuard, see “Configuring
HyperFabric with ServiceGuard” on page 103, as well as Managing
MC/ServiceGuard Part Number B3936-90065 March 2002 Edition.
• High Availability (HA): Supported
When applications use HMP to communicate between HP 9000
nodes in a HyperFabric cluster, you can configure ServiceGuard and
the EMS monitor to identify node failure and automatically failover
to a functioning HP 9000 node.
For more information on HA when running HMP applications,
contact your HP representative.
• Transparent Local Failover: Supported
HMP supports Transparent Local Failover in the HyperFabric
version B.11.11.03.
When a HyperFabric resource (adapter, cable, switch or switch port)
fails in a cluster, HMP transparently fails over traffic using other
available resources. This is accomplished using card pairs, each of
which is a logical entity that comprises a pair of HF2 adapters on a
HP 9000 node. Only Oracle applications can make use of the Local
Failover feature. HMP traffic can only fail over between adapters
that belong to the same card pair. Traffic does not fail over if both the
adapters in a card pair fail. However, administrators do not need to
configure HF2 adapters as card pairs if TCP/UDP/IP is run over HF2
or MPI uses HMP.
When HMP is configured in the local failover mode, all the resources
in the cluster are utilized. If a resource fails in the cluster and is
restored, HMP does not utilize that resource until another resource
fails.