RE: New Sun/Oracle Blueprint available

From: Mohan, Ross <MohanR_at_STARS-SMI.com>
Date: Fri, 26 Jan 2001 11:20:14 -0500
Message-Id: <10753.127595@fatcity.com>

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Dave,

How gracious of both of you! thanks....

There are *excellent* clarifications and additions in here.

Now, if only we could get this level of openness and support from Oracle!

Thanks again,

Ross Mohan

(p.s. final rhetorical comments embedded in <snip>'ed text below.)

-----Original Message-----
From: David Miller [mailto:djm_at_oregon.West.Sun.COM] Sent: Thursday, January 25, 2001 6:11 PM To: Multiple recipients of list ORACLE-L Subject: RE: New Sun/Oracle Blueprint available

Hi Ross,

I forwarded your comments on to the author, Bob Sneed, who replies below.

Dave Miller
Sun Microsystems, Inc.

<snip>".....Some vendors, like HP an IBM (pre-Dynix), have not historicaly
offered 'truss' (or 'strace', or similar) at the command online to allow users to make misdiagnoses such as we have seen so often with truss and libaio...."

|| I can't speak for IBM (non-Sequent part) or HP, but..."my old favorite", Sequent, had truss...debug...all the excellent hard core SA tools you could want, and more.

<snip>....the logic is a 'feature' because ...

	if (ioctl() says it's RAW)
	then do KAIO
	else do LWP-based AIO

... would require an extra system call per I/O compared to the way it is now implemented ...

	do KAIO
	if (that failed)
	then do LWP-based AIO

... and as it turns out, the extra kaio call for the LWP case is a very slight per-call overhead to the LWP-managed logic. I am sympathetic to the notion that 'clever' is merely 'irritating' when the documentation is not there. I would support a customer filing a bug report complaining that kaio(2) is not documented, and should be, even if only to say that it is not a 'supported' or 'exposed' interface.

|| Bingo! Nicely presented and well-put.

Good comment. The constraint was removed at 8.1.7, and will be with 9i, I am told. 8.1.7 introduces a new init.ora parameter to allow re-enabling AIO to ordinary files. At the time the original copy was written, the 8.1.7 news was not out.

|| Another good clarification!

I value all feedback (short of vulgar name-calling :-)), and your feedback in particular is quite high quality.

|| Thanks! My esteem for the "Blueprint" has tripled as a result of this follow-up and the fact that I can infer the tech note will be an evolving work in progress.

The material has been test-flown with the collaboration of Oracle folks from the Oracle Centers of Excellence, and presented by invitation at Oracle internal symposia. Providing all the evidence of consensus is beyond the scope of the document, but the document does represent the consensus I've observed in my travels.

|| Take my comment, if possible, as a gripe against Oracle's *lack* of this kind of openness in its "support" offerings.

<snip>....Quite a valid comment. These particular tidbits seem to have
caused 80% of
the grief we saw in 1999/2000, and much of the grief we continue to see.

|| Amen. These ( well, 90% of them ) were all things I have seen in the time period you cite, hence my aggressive interest in them.

<snip>....If this ever matures into a book, "Best Practices" will be only
one chapter.

|| Book! Yay! Do it! I'd love to review it.

Thank you for your time and thoughtful comments. I'd be delighted to hear your feedback and experiences with these 'tidbits' and any others you think might fit the mould.

|| Off the cuff, I'd only add a bit about using mkfs inode flags to significantly reduce the numbers of inodes given to "database" filesystems. Often, database servers have just a few files per filesystem, and 100,000 allocated inodes are not necessary.....Thanks to you, Bob, for the johnny-on-the-spot answers and openness. Best of luck to you!

Already Signed Up as a Reviewer for the Book,

Ross Mohan
Senior System Engineer
SAIC ------_=_NextPart_001_01C087B3.DD0FA660
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Dave, 


How gracious of both of you! thanks....


There are *excellent* clarifications and additions in =
here.


Now, if only we could get this level of openness and =
support from Oracle!


Thanks again, 


Ross Mohan


(p.s. final rhetorical comments embedded in =
<snip>'ed text below.)


-----Original Message-----
 From: David Miller [<A =
HREF=3D"mailto:djm_at_oregon.West.Sun.COM">mailto:djm_at_oregon.West.Sun.COM</= A>]
 Sent: Thursday, January 25, 2001 6:11 PM
 To: Multiple recipients of list ORACLE-L
 Subject: RE: New Sun/Oracle Blueprint =
available

 

Hi Ross,


I forwarded your comments on to the author, Bob =
Sneed, who replies below.


Dave Miller
 Sun Microsystems, Inc.


<snip>".....Some vendors, like HP an IBM =
(pre-Dynix), have not historicaly offered 'truss' (or 'strace', or = similar) at the command online to allow users to make misdiagnoses such = as we have seen so often with truss and libaio...."

||  I can't speak for IBM (non-Sequent part) or =
HP, but..."my old
 favorite", Sequent, had truss...debug...all the =
excellent hard core
 SA tools you could want, and more. 


<snip>....the logic is a 'feature' because =
...


        if =
(ioctl() says it's RAW)
         then do =
KAIO
         else do =
LWP-based AIO

 
 

... would require an extra system call per I/O =
compared to the way
 it is now implemented ...


        do =
KAIO
         if (that =
failed)
         then do =
LWP-based AIO
        =20
 ... and as it turns out, the extra kaio call for the =
LWP case is a very
 slight per-call overhead to the LWP-managed =
logic.  I am sympathetic to
 the notion that 'clever' is merely 'irritating' when =
the documentation is
 not there.  I would support a customer filing a =
bug report complaining that
 kaio(2) is not documented, and should be, even if =
only to say that it is
 not a 'supported' or 'exposed' interface.


||  Bingo! Nicely presented and well-put. =



Good comment.  The constraint was removed at =
8.1.7, and will be with 9i,
 I am told.  8.1.7 introduces a new init.ora =
parameter to allow re-enabling
 AIO to ordinary files.  At the time the =
original copy was written, the
 8.1.7 news was not out.


||  Another good clarification!


I value all feedback (short of vulgar name-calling =
:-)), and your feedback
 in particular is quite high quality.


||  Thanks!  My esteem for the =
"Blueprint" has tripled as a result
 of this follow-up and the fact that I can infer the =
tech note
 will be an evolving work in progress. 


The material has been test-flown with the =
collaboration of Oracle folks
 from the Oracle Centers of Excellence, and presented =
by invitation at
 Oracle internal symposia.  Providing all the =
evidence of consensus is
 beyond the scope of the document, but the document =
does represent the
 consensus I've observed in my travels.


||  Take my comment, if possible, as a gripe =
against Oracle's *lack*
 of this kind of openness in its "support" =
offerings. 


<snip>....Quite a valid comment. These =
particular tidbits seem to have caused 80% of
 the grief we saw in 1999/2000, and much of the grief =
we continue to see.


||  Amen. These ( well, 90% of them ) were all =
things I have seen in 
 the time period you cite, hence my aggressive =
interest in them. 


<snip>....If this ever matures into a book, =
"Best Practices" will be only one chapter.


||  Book!  Yay! Do it! I'd love to review =
it. 


Thank you for your time and thoughtful =
comments.  I'd be delighted to
 hear your feedback and experiences with these =
'tidbits' and any others
 you think might fit the mould.


||  Off the cuff, I'd only add a bit about using =
mkfs inode flags to 
 significantly reduce the numbers of inodes given to =
"database" filesystems.
 Often, database servers have just a few files per =
filesystem, and 100,000
 allocated inodes are not necessary.....Thanks to =
you, Bob, for the 
 johnny-on-the-spot answers and openness. Best of =
Received on Fri Jan 26 2001 - 10:20:14 CST