Browse Prior Art Database

Efficient Technique for Preparing Transactions in Large Systems

IP.com Disclosure Number: IPCOM000103833D
Original Publication Date: 1993-Feb-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 4 page(s) / 134K

Publishing Venue

IBM

Related People

Buxton, RF: AUTHOR [+5]

Abstract

Disclosed is a technique for efficiently processing transactions in a large system environment. The technique eliminates much of the overhead required to start a transaction in a large system. This is achieved by using a cache, or fast access memory, to save and access an internal representation of the transaction program and its resource requirements.

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Efficient Technique for Preparing Transactions in Large Systems

      Disclosed is a technique for efficiently processing
transactions in a large system environment.  The technique eliminates
much of the overhead required to start a transaction in a large
system.  This is achieved by using a cache, or fast access memory, to
save and access an internal representation of the transaction program
and its resource requirements.

      One of the key attributes of any transaction processing system
is response time:  The amount of time it takes from the moment a user
invokes a transaction to the time the transaction responds to the
user (which may in fact be at the conclusion of the transaction).

Transaction response time is directly affected by the amount of time
it takes a system to start a transaction:  the longer the system
takes to allocate the resources required by a transaction and invoke
a transaction program, the longer the response time for the
transaction.  This technique minimizes the amount of processing
required to start a transaction in a large system, thereby reducing
transaction response time.

      The first step in this technique is to transform an
externalized representation of a transaction, consisting of the
transaction program and its resource requirements, into a
representation which is identical to, or very similar to, the
internal representation used by the system to allocate the resources
required by the transaction and invoke the transaction program.  The
externalized representation of the transaction may include the name
and location of the transaction program, input and output
files/datasets required by the transaction, output distribution
information, resource restrictions (such as CPU time), and user
identification information (such as userid, accounting information,
etc.) if it is known prior to invocation.  If the externalized
representation of the transaction contains information which is not
static, such as information which must be changed for each user, this
transformation can create a generic, or "untailored" representation
of the transaction.

      In an MVS environment, the externalized representation of a
transaction is most conveniently embodied by Job Control Language
(JCL), consisting of the statements which identify the program to be
invoked and the resources it requires.  Using MVS JCL as the
embodiment, non-static information is represented using the &SYSUID
substitution string in the JCL, and the internal representation is
generated using the MVS converter/interpreter, which converts the JCL
into  format which can be used by an MVS scheduler and initiator to
allocate the resources required by the transaction and invoke the
transaction program.

      Once the internal representation of the transaction has been
created, it is stored in a cache, or fast access memory, so that it
can be quickly accessed when a user invokes the transaction.  In the
MVS JCL embodiment, the...