Re: Create Index Mysteriously Slow at the End - IDS 11.10.UC2W2 -RedHatEL5
"Superboer" <superboer7@t-online.de> wrote in message
news:475f7a43-274a-4512-ab0f-6d872018f293@59g2000hsb.googlegroups.com...
> what happens when you try onmode -B
With LRUs set to 127, Cleaners set to 127, LRU min/max set to 70/80,
RTO_SERVER_RESTART disabled and CKPTINTVL set to 8 hours I execute onmode -B
and continuously execute onmode -B each time I see the cleaner stop writing
to a chunk (state = C).
Doing this I get about the same performance as my previous test of
RTO_SERVER_RESTART 0, aka disabled
CKPTINTVL 28800, 8 hoursLRUs 1
CLEANERS 1LRU min dirty 0.00000
LRU max dirty 0.00001
The only difference seems to be most of the writes are chunk writes and not
LRU writes, no change in performance.
Still 5 minutes to scan the data pages, 10 minutes to write the index pages
and 20 minutes to read the index pages.
Thanks for the suggestion,
Andrew
Hello Andrew,
hmmm sound like there are issues with checkpointing....
i suggest to file a case @ibm/informix; this may bite all of us
someday...
anyway you could
try and generate your own stuff:
create procedure generatechkpt()define dirty decimal (4,3);
while (1=1)
select ( sum(lru_nmod) / sum ( lru_nfree + lru_nmod ))
into dirty
from syslrus ;
if (dirty < 0.75 ) then
system "sleep 1";
else
system "onmode -B";
end if
end while ;
end procedure;
execute the above as informix and set lrumax and mindirty to 99.
when the index build is done then do manually an onmode -B followed by
a onmode -c
see you
Superboer.
On 16 mei, 00:09, "Andrew Ford" <af...@networkip.net> wrote:
> "Superboer" <superbo...@t-online.de> wrote in message
>
> news:475f7a43-274a-4512-ab0f-6d872018f293@59g2000hsb.googlegroups.com...
>
> > what happens when you try onmode -B
>
> With LRUs set to 127, Cleaners set to 127, LRU min/max set to 70/80,
> RTO_SERVER_RESTART disabled and CKPTINTVL set to 8 hours I execute onmode -B
> and continuously execute onmode -B each time I see the cleaner stop writing
> to a chunk (state = C).
>
> Doing this I get about the same performance as my previous test of
>
> RTO_SERVER_RESTART 0, aka disabled
> CKPTINTVL 28800, 8 hours> LRUs 1
> CLEANERS 1> LRU min dirty 0.00000
> LRU max dirty 0.00001
>
> The only difference seems to be most of the writes are chunk writes and not
> LRU writes, no change in performance.
>
> Still 5 minutes to scan the data pages, 10 minutes to write the index pages
> and 20 minutes to read the index pages.
>
> Thanks for the suggestion,
>
> Andrew