Hello Henry,
So, now what?? Why is one server giving me 350k consistent gets/per second
and the other is ~800k? Is it hardware? /proc/cpuinfo shows the same cpu for
each box
Henry Poras <henry.poras@xxxxxxxxx> hat am 9. August 2017 um 23:46--
geschrieben:
I have two identical servers (or so I am told), but application work is
running 2-3 times slower on one than the other. Using Tanel's snapper, I see
that all active sessions are all on CPU. Viewing top shows me the same thing,
each session pegs a cpu. We also found that it wasn't particular SQL that
slowed down across severs, but it looked like everything was slow. A select
count(*) from dba_objects showed this behavior as did Jonathan Lewis's
kill_cpu script. This gave me something to test with. Running a 10046, I saw
the same amount of resource utilization (parse count, fetch count, cr count,
...), no contention (wait events), but one server finished 2.5 times faster
than the other. Looking at session stats through snapper, I see that the
number of session logical reads per sec (~all of which are consistent reads)
is ~ 2.5 times higher on one server than the other. That explains why it
takes one longer to finish.
So, now what?? Why is one server giving me 350k consistent gets/per second
and the other is ~800k? Is it hardware? /proc/cpuinfo shows the same cpu for
each box. Is it hidden in the Oracle code path? I realize that not all LIO
are created equal, but how do I check this? I am running on SE12.1.0.1
Any and all thoughts welcome.
Henry