Re: Application performance

Just doing the numbers in my head (always dodgy!) it looks like your buffer wait ratio is a bit high, you need more LRUS (and CLEANERS). From: bwhite@deroyal.com > >In article <398743A9.901FC298@americasm01.nt.com>, > Rudy Fernandes <rferdy@americasm01.nt.com> wrote: > > With just 56000 odd page writes against 4million odd page reads in 16 > > hours(?), excessive reads could be causing your problems. > > > > Try changing the onconfig parameter OPTCOMPIND to 0. Under OLTP >(especially > > with MEDIUM stats), this could help by pointing queries towards >nested-loop > > joins (i.e index usage). You will have to bounce your engine for the > > parameter to take effect. > > > > The fact that you have FG Writes (onstat -F) is not a good sign. It >could > > be related to read inefficiency because of OPTCOMPIND. On the other >hand, > > it could mean that you need to increase BUFFERS. How much memory >does your > > box have? > >3 G memory. > >I considered the FG writes relatively low (I've read messages in this >group before that said sometimes it's virtually impossible to >completely eliminate FG writes. My FG writes are .02 % of my total >writes, is this too high? > > > > > Also, could you post onstat -p, onstat -u (in full), onstat -g ses (in > > full). > >Sorry, I missed the paste... > >onstat -p> >Informix Dynamic Server Version 7.31.UC5 -- On-Line -- Up 1 days >01:40:19 -- 336448 Kbytes > >Profile >dskreads pagreads bufreads %cached dskwrits pagwrits bufwrits %cached >4998586 5317163 216746561 97.69 400311 538439 4911166 91.85 > >isamtot open start read write rewrite delete commit >rollbk >227288286 748153 27239316 67637713 3669800 86745 77100 >275969 4 > >gp_read gp_write gp_rewrt gp_del gp_alloc gp_free gp_curs >0 0 0 0 0 0 0 > >ovlock ovuserthread ovbuff usercpu syscpu numckpts flushes >0 0 58 16970.52 7824.27 77 170 > >bufwaits lokwaits lockreqs deadlks dltouts ckpwaits compress seqscans >809483 0 151762735 0 0 52 24342 105517 > >ixda-RA idx-RA da-RA RA-pgsused lchwaits >945343 25131 897353 1866197 7052 > > > > > > > Rudy > > > > bwhite@deroyal.com wrote: > > > > > Hello > > > > > > I upgraded from SE to IDS 7.31.UC5 at the end of June. I have four > > > large applications that run at certain times during the month. These > > > applications take twice as long to run on IDS than SE! I did not >want > > > to post until I did some performance tuning with the help of various > > > resources & I wanted to get more comfortable with IDS. I have made >many > > > changes, and feel good about my monitoring statistics (Bufwait >ratio, > > > Buffer Turnover, IO, Checkpoint duration (around 5 during peak, as >high > > > as 8, but not very often), etc). I have not mastered the art of >update > > > statistics (high on specific columns etc), so I do an update >statistics > > > medium on the entire database nightly. I have included various >onstats > > > (although I'm sure I left some important ones out). I reset stats > > > nightly. I've tried many of the suggestions of this group, and >they've > > > helped my onstats, but not my applications. Nothing jumps out in the > > > set explain of the applications. I am new to IDS in production, so> > > please be gentle. > > > > > > ... > > > > > > >Sent via Deja.com http://www.deja.com/ >Before you buy. ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com