I have re-run the same test using IBM JVM 1.5 on Linux. The resulting
graphs are attached. Compared to the results when running on Sun JDK 6
the regression seems to influence the performance less on IMB JBM/Linux,
but it is still in the order of 8-10% in my test.
I have also re-run the test using Sun JDK 5 VM and this also shows that
there seems to be a regression (see attached graph).
Olav
Olav Sandstaa wrote:
To see the effect of this in a different environment I started a
similar test running with IBM 1.5 VM on Linux. Unfortunately, the
machine I decided to use was a shared server so during part of the
test run some other testing have been running in parallel. I plan to
try to re-run these tomorrow.
But anyway, I am attaching the graph even if it is not correct. It
seems that the negative effect of this patch is much less when running
on the IBM VM/Linux (the last part of the second curve I expect was
run in parallel with some other testing). So if anyone is looking into
this and using a different VM (or OS) than I did they might not see
the large drop I see in my tests.
Olav
Mike Matrigali wrote:
Are these tests checked in so that I can run them in my environment?
Olav Sandstaa wrote:
The two last days I have seen a performance regression in some of
the performance tests I run. For some of the tests the reduction in
throughput is about 15 percent. It seems like the regression is
introduced by the latest check-in on DERBY-2537, svn 531971.
I have attached a graph showing the throughput I get when running
single-record select operation on a table. The queries use a
secondary index for finding the record to select. The test has been
run with 1 to 20 concurrent client against embedded Derby. I have
run the test with and without SVN 531971. As the graph shows, the
performance reduction is between 12 and 15 percent for all runs.
The schema looks like this:
CREATE TABLE t1 id INTEGER sec_id INTEGER data CHARACTER(100)
PRIMARY KEY(id))
CREATE INDEX nonprimary_index ON t1 (sec_id)
Each query do the select on the secondary index and retrieves the
data field (a CHARACTER(100) field).
I would expect some of the changes done in the patch to have some
influence on the performance, but not in the order of 10-15 percent.
The tests are run on a 2 CPU Opteron server running Solaris 10 and
JDK 6.
Olav
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