[hyades-dev] (no subject)

[Richard Duggan <rduggan@xxxxxxxxxx>]

We are making a refresh of the Hyades 3.0.1 candidate driver that was
dropped yesterday.  I have provided details below regarding what is
changing in this driver.


Problem Statement:  Mapping of Java 1.4 LogRecords to Common Base Events
result in severe performance degradation.

Background:  As part of the JSR-47 implementation, JDK 1.4 provides a
LogRecord data structure for placing logging information into a data
structure which can be consumed by any Logger that is registered within the
JVM.  As part of Hyades we have provided a specialization of the LogRecord
(CommonBaseEventLogRecord) which uses a delegation model to keep the
logging data in a Common Base Event  data structure.  This allows
information that is logged to this structure to both be consumed by loggers
that are aware of Common Base Events and those which are not.  The problem
lies in the delegation model.  Many of the fields which are defined within
the JSR-47 LogRecord are not cleanly mapped to Common Base Event fields.
As a result, these fields are mapped to ExtendedDataElements within the
CommonBaseEvent data structure.  Since the data is mapped to a collection
(EMF EList) of ExtendedDataElements it becomes very expensive to do
retrieval's of values that have been stored within the LogRecord.  The
normal programming model for JSR-47 implies the user is setting the data
once and many loggers are retrieving the data many times.  Needless to say,
we needed to expedite the retrieval of the data.


Fix:  A cache of the data that is added to the LogRecord.  This allows
CommonBaseEventLogRecords to be much more efficient in retrieving the data
from the LogRecord when dealing with loggers which are not aware of the
CommonBaseEvent data structure.


Effected components:  This fix is isolated to the CommonBaseEventLogRecord
class and will only effect persons or projects which are using the
CommonBaseEventLogRecord as their logging record type.

Richard K. Duggan
Problem Determination Enablement
IBM Toronto Laboratory
External: 905-413-2396
Internal: 969-2396