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К этому устройству также есть другие инструкции:
Фрагмент инструкции
FTAM Application Management
Fault Tolerance
PDU Sizes
A PDU is the encoded message that is transferred across an OSI network between the
initiator and responder. The sender (either initiator or responder) encodes the
parameters associated with an FTAM primitive into an FTAM PDU (FPDU) for transfer
across the network. The receiver decodes the FPDU back into a primitive after it is
received at its destination.
The NonStop initiator, in accordance with the NIST agreements, limits the maximum
size of an outgoing FPDU to 16 KB. The PDU size that provides the best performance
for your application will depend on many factors, including the logic of that application;
the operational and performance characteristics of the remote FTAM responder and its
local file system; the structures of existing files; and the underlying OSI network.
You never explicitly set the FPDU size for your application, but you can calculate the
size of the encoded file data sent to the remote responder according to the formulas
described in Limits on Data-Value Sizes on page 3-15. These formulas are based on
the structure of information contained in the data-value parameter, also described in
Section 3, NonStop FTAM Programming, and apply only to PDUs that contain primitive
strings (PDUs containing constructed strings have additional overhead). The formulas
do not apply to FTAM protocol data. For more information, see Limits on Data-Value
Sizes on page 3-15.
Because you do not explicitly set the FPDU size, you must use SCF to set the
transport PDU (TPDU) size for your application. If your application sends and receives
fewer than 450 bytes of data at a time, the default TPDU size of 512 is adequate. If it
sends larger blocks of data, you should set the TPDU size to a much larger value,
typically 8192 bytes for an application using the NonStop LAN Access Method (TLAM)
or 4096 bytes for an application using X25AM. In addition, you might also need to
consider the X.25 packet size in this calculation. For information on setting TPDU size
(which is an attribute of the OSI/AS subsystem), see the OSI/FTAM Configuration and
Management Manual or the OSI/AS Configuration and Management Manual.
Fault Tolerance
NonStop FTAM provides limited fault tolerance if you configure your initiator processes
to run as NonStop process pairs. You can do this by using the SCF ADD PROCESS or
ALTER PROCESS command to specify a backup CPU when you configure your
initiator process. When processes run as NonStop process pairs, the startup
configuration information for the primary process is checkpointed, and in case of
hardware or software component failure, the backup process takes over. (For
explanations of process pairs and checkpointing, see the Guardian Programmer’s
Guide.)
In the case of failure of the primary initiator process, all outstanding NonStop FTAM
associations, as well as the associated OSI/AS connections, are terminated when the
process fails. If the NonStop FTAM initiator process is running as a NonStop process
pair, the backup NonStop FTAM initiator process takes over. You then need to reinitiate
the FTAM associations by recalling the procedure that originally established your
HP NonStop OSI/FTAM Programming Guide—528612-001
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...Эта инструкция также подходит к моделям:
Компьютеры - HP Integrity NonStop J-Series (1.09 mb)
Компьютеры - HP NonStop G-Series (1.09 mb)
Компьютеры - HP NonStop L-Series (1.09 mb)