Specifies the number of group evaluator threads to create
when Enterprise Replication starts,
and enables parallelism.
onconfig.std value
1,2
units
evaluator thread instances
range of values
first value: 0 or a positive integer representing the number of evaluator
threads to create per CPU VP. Although evaluator threads are not assigned to specific CPU VPs, you
can create evaluator threads that are proportional in number to the number of CPU VPs.
second
value: 0 or a positive integer representing the additional number of evaluator
threads to create irrespective of the number of CPU
VPs.
Do
not set both CDR_EVALTHREADS values to 0.
takes effect
When the database server is shut down and restarted, or immediately
after the cdr change onconfig command is used
Enterprise Replication evaluates the images of a row in
parallel to assure high performance. Processing in Parallel for High Performance illustrates how Enterprise
Replication uses parallel processing to evaluate transactions for
replication. Figure 1: Processing in Parallel for High Performance
The CDR_EVALTHREADS configuration parameter specifies
the number of grouper evaluator threads to create when Enterprise Replication starts
and enables parallelism. The format is:
(per-cpu-vp,additional)
The following table provides four examples of CDR_EVALTHREADS.
Number of Threads
Explanation
Example
1,2
1 evaluator thread per CPU VP, plus 2
For a 3 CPU VP server: (3 * 1) + 2 = 5
2
2 evaluator threads per CPU VP
For a 3 CPU VP server: (3 * 2) = 6
2,0
2 evaluator threads per CPU VP
For a 3 CPU VP server: (3* 2) +0 = 6
0,4
4 evaluator threads for any database server
For a 3 CPU VP server: (3 * 0) +4 = 4
Attention: Do not configure the total number
of evaluator threads to be smaller than the number of CPU VPs in the
system. As noted above, do not set both CDR_EVALTHREADS values to 0.
