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Improved Work Distribution in a Multi-Processing Client-Server Environment

IP.com Disclosure Number: IPCOM000116847D
Original Publication Date: 1995-Nov-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Bjork, TA: AUTHOR [+3]

Abstract

For an optical library, some functions can be performed by either the client or the server. A technique to optimize the processing location is described. Specifically, the "copy file" operation can be done by either the server I/O Processor (IOP) or the host. Techniques are described to appropriately choose where the operation will be processed.

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This is the abbreviated version, containing approximately 52% of the total text.

Improved Work Distribution in a Multi-Processing Client-Server Environment

      For an optical library, some functions can be performed by
either the client or the server.  A technique to optimize the
processing location is described.  Specifically, the "copy file"
operation can be done by either the server I/O Processor (IOP) or the
host.  Techniques are described to appropriately choose where the
operation will be processed.

      The optical library consists of 1, 2, or 4 optical disk drives
and some number of storage slots where optical media are stored.  The
library is attached to the host computer with an intelligent I/O
processor.  This attached I/O processor has the ability to
independently handle a large amount of processing.

      One operation which can be handled completely in the IOP is
"copy file."  Processing this operation in the IOP eliminates the
need to buffer the data in the host and it obviously eliminates the
bus traffic moving the data to/from the host.

      However, not all copy file operations can be handled in the
IOP.  For example, a copy from one side of a media to the other side
cannot be done in the IOP because only one side of a media can be
accessed at one time.  For this reason the File Manager (FM)
executing in the host must provide the ability to handle copy file
operations also.  This leaves a choice:  should any particular copy
be handled by the server IOP or the FM in the host?

      The technique developed to optimize the choice of where a copy
file should be done starts with the addition of some feedback from
copy file operations done in the server IOP.  That feedback indicates
if media movement was required to complete the copy.  In most
situations, this is the logical equivalent of a "thrashing"
indicator.  After bo...