This is a follow-up article to the MySQL Super Smack benchmark results. Results from sql-bench benchmark suite can easily pinpoint some of the potential system bottlenecks. I find it especially useful for discovering filesystem performance or – better – slowness.
Results
Total execution time is: 562 seconds
# run-all-tests
alter-table: Total time: 8 wallclock secs ( 0.02 usr 0.01 sys + 0.00 cusr 0.00 csys = 0.03 CPU)
ATIS: Total time: 2 wallclock secs ( 1.20 usr 0.09 sys + 0.00 cusr 0.00 csys = 1.29 CPU)
big-tables: Total time: 5 wallclock secs ( 2.45 usr 0.08 sys + 0.00 cusr 0.00 csys = 2.53 CPU)
connect: Total time: 50 wallclock secs (12.74 usr 4.50 sys + 0.00 cusr 0.00 csys = 17.24 CPU)
create: Total time: 31 wallclock secs ( 1.20 usr 0.44 sys + 0.00 cusr 0.00 csys = 1.64 CPU)
insert: Total time: 397 wallclock secs (97.95 usr 13.61 sys + 0.00 cusr 0.00 csys = 111.56 CPU)
select: Total time: 44 wallclock secs ( 8.71 usr 0.88 sys + 0.00 cusr 0.00 csys = 9.59 CPU)
transactions: Test skipped because the database doesn’t support transactions
wisconsin: Total time: 3 wallclock secs ( 0.91 usr 0.23 sys + 0.00 cusr 0.00 csys = 1.14 CPU)
TOTALS 562.00 123.77 19.82 143.59 3425950
System specification can be found here.
ReiserFS vs others
In the age of Linux kernel 2.4.x we used ReiserFS v3 as the filesystem of choice. With the available options of ReiserFS (journal, performance), ext2 (stable but slow) and ext3 (probably stable, but not so speedy as ReiserFS) the choice was obvious. I skipped few years then and this year again tried using ReiserFS with linux 2.6.29.1 but it turned out to be even slower than ext2 was in the old days. Googling around for an answer gave some hints that ReiserFS has an issue with someting called BIG_KERNEL_LOCK on 2.6 kernels. I didn’t really investigate further, but went down the ext3 way.
Comments on test-create
If test-create takes much more time than, say, 30-60 seconds, then you definitely have a problem with filesystem write performance. On HP DL360 and DL380 class of servers this correlates with the presence and activation of BBWC (Battery-Backed Write Cache enabler kit). Without BBWC and hence without write cache enabled, this test took more than 10 minutes to complete. Thus, if you are purchasing some new HP servers, be sure that you also order BBWCs.
Question about test-insert
Looking at the test times, this test-insert result is really standing out. Again, I do not have any other data to compare it to, but somewhere deep down in my memory I seem to remember that the total time for all the tests was around 300 seconds. This obviously means that this test-insert result is the bad guy here. Can someone comment on this result, or paste in the comments his own? Thanks.
Feedback
If you have any questions, recommendations or benchmark results to compare, do not hesitate to leave a comment.