Compaq Reliable Transaction Router Getting Started page 75

shadow
The state of the server process that services a copy of the data
store or primary database. In the context of RTR, the shadow
method is transactional shadowing, not disk shadowing. Its
counterpart is primary.
SMP
Symmetric MultiProcessing.
standby
The state of the partition that can take over if the process for
which it is on standby is unavailable. It is held in reserve, ready
for use.
TPS
Transactions per second.
transaction
An operation performed on a database, typically causing an
update to the database. Analogous in many cases to a business
transaction such as executing a stock trade or purchasing an
item in a store. A business transaction may consist of one or
more than one RTR transaction. A transaction is classified as
original, replay, or recovery, depending on how it arrives at the
backend:
Original—Transaction arrived on the first attempt from the
client.
Replay—Transaction arrived after some failure as the
result of a re-send from the client (that is, from the client
transaction-replay buffers in the RTRACP).
Recovery—Transaction arrived as the result of a backend-
to-backend recovery operation (recovery from the
journal).
transaction controller
A transaction controller processes transactions. A transaction
controller may have 0 or 1 transactions active at any moment in
time. It is through the transaction controller that messages and
events are sent and received.
Glossary–9