If another database has a value of 200 for this parameter, that database would be
the commit point site for a distributed transaction involving those two databases. The COMMIT_
POINT_STRENGTH cannot exceed 255.
Because the scale is relative, you should set up a site-specific scale. Set the commit point on
your most reliable database to 200. Then, grade the other servers and databases relative to the
most reliable database. If, for example, another database is only 80 percent as reliable as the most
reliable database, assign it a commit point strength of 160 (80 percent of 200). Fixing a single
database at a definite point (in this case, 200) allows the rest of the databases to be graded on an
even scale. This scale should result in the proper commit point site being used for each transaction.
Monitoring Distributed Databases
Several key environmental performance measures must be taken into account for databases:
The performance of the host
The distribution of I/O across disks and controllers
The usage of available memory
For distributed databases, you must also consider the following:
The capacity of the network and its hardware
The load on the network segments
The usage of different physical access paths between hosts
None of these can be measured from within the database. The focus of monitoring efforts for
distributed databases shifts from being database-centric to being network-centric. The database
becomes one part of the monitored environment, rather than the only part that is monitored.
Pages:
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932