"Ivan Vasquez" <ivan_at_looker.itos.uga.edu> wrote in message news:<c4aafk$897$1_at_cronkite.cc.uga.edu>...
>...
> With only one instance up, any query runs quickly, as expected.
>
> With both instances up, I connect to instance A, run a long query (say,
> 30-seconds) and it runs normally. At this point I assume instance A has
> cached some or all the blocks used for the query.
>
> Then I connect to instance B and issue the same query as above. Rows are
> returned intermittently, up to 4-second delays in between. I assume in this
> case RAC is trying to ship whichever buffers are found in instance A instead
> of reading from disk. No DML activity is going on, it's just me and the
> database.
>
> What confuses me is that I don't see much traffic thru the interconnect, and
> CPU and disk utilization are far from high. Using vmstat I see increased
> context switches, but they are just as high as those in the instance that
> runs fine! I have read note 181489.1 but haven't found much help from it and
> wonder if it's something else inherent to my architechture (i386).
Ivan,
Can you tell us what wait events are shown in v$session_wait during
the "up to 4-second delays"?
If you don't mind, just for my curiosity, also run select event, op,
time, seq#, data from x$trace where sid = &sid and pid = &pid order by
time, and strace -p on the server processes for the sessions involved.
Yong Huang
(Email: yong321_at_yahoo.com)
Received on Tue Apr 06 2004 - 02:02:08 CDT
