Very slow connections to the sql servers - Toolserver-l

24 Sep 2012


      I am seeing my tools very slow connecting to the sql servers, such as
taking 33 or 79 seconds
just for figuring out the right server and connecting to it, and even
failing with «Can't connect to
MySQL server on 'sql-s4-rr.toolserver.org'» (not only on this server)
Are sql servers overloaded? Is it a problem with willow? Should we give
a kick to the tcp stack?
This anomaly is also visible from the command line, varying from immediate
connection to slow one:
$ time mysql -h sql-s4-rr.toolserver.org  -e 'SELECT VERSION()'
+-----------+
| VERSION() |
+-----------+
| 5.1.59    |
+-----------+
real    0m0.098s
user    0m0.003s
sys     0m0.009s
# Shouldn't it always so quick?
$ time mysql -h sql-s4-rr.toolserver.org  -e 'SELECT VERSION()'
+-----------+
| VERSION() |
+-----------+
| 5.1.59    |
+-----------+
real    0m4.803s
user    0m0.003s
sys     0m0.009s
$ time mysql -h sql-s4-rr.toolserver.org  -e 'SELECT VERSION()'
+-----------+
| VERSION() |
+-----------+
| 5.1.59    |
+-----------+
real    0m1.619s
user    0m0.003s
sys     0m0.009s
$ time mysql -h sql-s4-rr.toolserver.org  -e 'SELECT VERSION()'
+-----------+
| VERSION() |
+-----------+
| 5.1.59    |
+-----------+
real    0m4.222s
user    0m0.003s
sys     0m0.009s
$ time mysql -h sql-s4-rr.toolserver.org  -e 'SELECT VERSION()'
+-----------+
| VERSION() |
+-----------+
| 5.1.59    |
+-----------+
real    0m15.434s
user    0m0.003s
sys     0m0.008s
$ time mysql -h sql-s3-rr.toolserver.org  -e 'SELECT VERSION()'
+-----------+
| VERSION() |
+-----------+
| 5.1.59    |
+-----------+
real    0m13.463s
user    0m0.003s
sys     0m0.009s
$ time mysql -h sql-s3-rr.toolserver.org  -e 'SELECT VERSION()'
+-----------+
| VERSION() |
+-----------+
| 5.1.59    |
+-----------+
real    0m2.356s
user    0m0.003s
sys     0m0.009s
$ time mysql -h sql-s3-rr.toolserver.org  -e 'SELECT VERSION()'
+-----------+
| VERSION() |
+-----------+
| 5.1.59    |
+-----------+
real    0m1.850s
user    0m0.003s
sys     0m0.008s
$ time mysql -h sql-s3-rr.toolserver.org  -e 'SELECT VERSION()'
+-----------+
| VERSION() |
+-----------+
| 5.1.59    |
+-----------+
real    0m24.724s
user    0m0.003s
sys     0m0.008s