HP (Hewlett-Packard) 8.3 Garage Door Opener User Manual


 
HP OpenVMS Alpha Version 8.3 and HP OpenVMS Version 8.3-1H1 for Integrity Servers SPD 82.35.14
Shared page tables
Expandable global page table
Reserved memory registry
DECdtm Services
The DECdtm services embedded in the OpenVMS op-
erating system support fully distributed databases us-
ing a two-phase commit protocol. The DECdtm ser-
vices provide the technology and features for distributed
processing, ensuring both transaction and database in-
tegrity across multiple HP resource managers. Updates
to distributed databases occur as a single all-or-nothing
unit of work, regardless of where the data physically re-
sides. This ensures the consistency of distributed data.
DECdtm services allow applications to define global
transactions that can include calls to any number of HP
data management products. Regardless of the mix of
data management products used, the global transac-
tion either commits or aborts. OpenVMS is unique in
providing transaction processing functionality with base
operating system services.
DECdtm features include:
Embedded OpenVMS system services that support
the DECtp architecture, providing the features and
technology for distributed transaction processing.
Ability for multiple disjoint resources to be updated
automatically. These resources can be either physi-
cally disjointed on different clusters at separate sites,
or logically disjointed in different databases on the
same node.
Ability to use the X/Open Distributed Transaction
Processing XA interface that enables the DECdtm
transaction manager to coordinate XA-compliant re-
source managers (the HP DECdtm XA Veneer), and
XA-compliant transaction processing systems to co-
ordinate DECdtm-compliant resource managers (the
DECdtm XA Gateway).
Robust application development. Applications can
be written to ensure that data is never in an incon-
sistent state, even in the event of system failures.
Ability to be called using any HP TP monitor or
database product. This is useful for applications us-
ing several HP database products.
Interprocess Communication
OpenVMS provides the following facilities for applica-
tions that consist of multiple cooperating processes:
Mailboxes as virtual devices that allow processes to
communicate with queued messages.
Shared memory sections on a single processor or an
SMP system that permit multiple processes to access
shared address space concurrently.
Galaxywide sections on a Galaxy platform that permit
multiple processes in multiple instances to access
shared address space concurrently.
Common event flags that provide simple synchro-
nization.
A lock manager that provides a more comprehen-
sive enqueue/dequeue facility with multilevel locks,
values, and asynchronous system traps (ASTs).
Intracluster communication services through which
two processes running on the same system or on dif-
ferent OpenVMS Cluster nodes can establish a con-
nection and exchange data.
Logical names through which one process can pass
information to other processes running on the same
system or on different OpenVMS Cluster nodes.
Network interprocess communication is available via
TCP/IP Services and DECnet-Plus (product licenses
are required).
Symmetric Multiprocessing (SMP)
OpenVMS provides symmetric multiprocessing (SMP)
support for Alpha and Integrity servers multiprocessor
systems. SMP is a form of tightly coupled multipro-
cessing in which all processors perform operations si-
multaneously. All processors perform operations in all
OpenVMS access modes, user, supervisor, executive,
and kernel.
OpenVMS SMP configurations consist of multiple CPUs
executing code from a single shared memory address
space. Users and processes share a single copy of
OpenVMS for Integrity servers or OpenVMS Alpha ad-
dress space. SMP also provides simultaneous shared
access to common data in global sections to all proces-
sors. OpenVMS SMP selects the CPU where a process
will run based on its priority and in special cases as di-
rected by the application. OpenVMS uses a specialized
scheduling algorithm when running a nonuniform mem-
ory access (NUMA) platform.
SMP support is an integral part of OpenVMS and is
provided to the user transparently. Because an SMP
system is a single system entity, it is configured into
a network and OpenVMS Cluster configurations as a
single node.
The maximum number of supported CPUs in an SMP
configuration is 32.
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