Re: Poor RAC inter-instance performance

Yes Mike, I have both, and for the interconnect I have entries on /etc/hosts.

Right now I'm considering tweaking the sysctl.conf as Daniel has suggested. Any other suggestions are welcome. I would also like to hear if others have had the same issues.

Ivan.

"Mike Ault" <mikerault_at_earthlink.net> wrote in message news:37fab3ab.0403301206.470e1965_at_posting.google.com...
> "Ivan Vasquez" <ivan_at_looker.itos.uga.edu> wrote in message
news:<c4aafk$897$1_at_cronkite.cc.uga.edu>...
> > I'm testing a 2-node Linux RAC installation that's performing poorly
under
> > certain circumstances. The cluster is using 1G NICs as interconnect. I
> > already know I'm not supposed to ask for great performance out of it,
> > however the interconnect's capacity is far from reached whenever I
notice
> > bad performance.
> >
> > Here is the behavior:
> >
> > 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).
> >
> > Thanks in advance for any clues.
> > Ivan.
>
> Of course I mean a private interconnect and public network...not to
> confuse the more literal of the group...
>
> Mike
Received on Wed Mar 31 2004 - 12:42:32 CST