Transaction processing monitors (TPM) ensure transactions process completely or are rolled back if errors occur. TPMs work in multi-tier architectures by forwarding transactions between servers running on different platforms. TPMs use ACID properties to provide atomicity, consistency, isolation, and durability of transactions. Examples of TPMs include IBM's CICS and BEA's TUXEDO. TPMs are critical for ensuring transactions are processed reliably in multi-step distributed systems.
3. What is Transaction Processing
Monitor?
Transaction Processing Monitor is a
program that monitors a transaction as it
passes from one stage in a process to
another.
The TP monitor's purpose is to ensure
that the transaction processes completely.
If an error occurs it takes appropriate
actions.
It is used in 2-tier, 3-tier and n-tier
architectures. 3
4. Introduction contd......
A TPM is critical in multi-tier architectures
because a given transaction may be
forwarded to any one of several servers with
processes running on different platforms.
After completing each transaction, the TPM
can process another transaction without
being influenced by the previous transaction.
Examples of TPM are:
CICS (Customer Information Control
System) by IBM.
TUXEDO by BEA.
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5. Working Mechanism
The working mechanism of TPM can be
described with the help of ACID
properties.
◦ Atomicity: It defines all transactions are
either performed completely or are not done
at all; a partial transaction that is aborted must
be rolled back.
◦ Consistency: It ensures that the system
remains in a consistent state before the start
and end of the transaction. 5
6. Working Mechanism cont.
Isolation: It refers to the requirement that
other transactions or processes cannot
access or see the data in an intermediate
state during a transaction.
Durability: Once a transaction is
completed, the changes must be visible and
it cannot be undone.
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