Thread

1. Win32 Powerfail testing - results

   Dave Page <dpage@vale-housing.co.uk> — 2003-02-03T16:51:33Z

   Well the results are finally in. Hopefully we can concentrate on putting
   them right, rather than having a round of "told you so's" :-)
   
   I modified the test program slightly to improve the consistency checks.
   The updated version is attached.
   
   Regards, Dave.
   
   System
   ======
   
   Gigabyte GA-6VTXD Motherboard
   Dual 1GHz PIII Processors
   1Gb Non-ECC RAM
   Fujitsu MPG3240AH IDE Disk Drive
   
   Enhanced IDE Performance disabled in the BIOS.
   
   Test
   ====
   
   Test program run from a seperate machine.
   20 Tests per OS.
   Powerfail randomly applied.
   
   
   Windows 2000 Testing
   ====================
   
   Write back cache on IDE disk disabled.
   Clean installation of Windows 2000 Server with Service Pack 3
   
   Run | Errors Detected
   =============================================================
    01 | None
    02 | None
    03 | None
    04 | None
    05 | None
    06 | None
    07 | COUNT CHECK - Duplicate or missing rows detected (10262)!!
    08 | None
    09 | DISTINCT CHECK - Duplicate or missing rows detected (9893)!!
       | COUNT CHECK - Duplicate or missing rows detected (9893)!!
    10 | None
    11 | None
    12 | None
    13 | None
    14 | COUNT CHECK - Duplicate or missing rows detected (10024)!!
    15 | None
    16 | None
    17 | None
    18 | None
    19 | None
    20 | None
   
   Linux Testing
   =============
   
   Clean installation of Slackware Linux 8.1 on ext3
   Kernel 2.4.18
   
   Run | Errors Detected
   =============================================================
    01 | None
    02 | None
    03 | None
    04 | None
    05 | None
    06 | None
    07 | None
    08 | None
    09 | None
    10 | None
    11 | None
    12 | None
    13 | None
    14 | None
    15 | None
    16 | None
    17 | None
    18 | None
    19 | None
    20 | None
   

2. Re: Win32 Powerfail testing - results

   Vince Vielhaber <vev@michvhf.com> — 2003-02-03T17:20:13Z

   On Mon, 3 Feb 2003, Dave Page wrote:
   
   > Well the results are finally in. Hopefully we can concentrate on putting
   > them right, rather than having a round of "told you so's" :-)
   >
   > I modified the test program slightly to improve the consistency checks.
   > The updated version is attached.
   
   [...]
   
   >
   > Run | Errors Detected
   > =============================================================
   >  07 | COUNT CHECK - Duplicate or missing rows detected (10262)!!
   >  09 | DISTINCT CHECK - Duplicate or missing rows detected (9893)!!
   >     | COUNT CHECK - Duplicate or missing rows detected (9893)!!
   >  14 | COUNT CHECK - Duplicate or missing rows detected (10024)!!
   
   Out of curiousity, what was required to return things to normal
   again?
   
   Vince.
   -- 
    Fast, inexpensive internet service 56k and beyond!  http://www.pop4.net/
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3. Re: Win32 Powerfail testing - results

   Rod Taylor <rbt@rbt.ca> — 2003-02-03T18:34:20Z

   > I modified the test program slightly to improve the consistency checks.
   > The updated version is attached.
   
   For curiosity sake, I've compiled it and am running it on FreeBSD with
   soft-updates enabled.
   
   A few variable declarations needed to be bumped up to the top of their
   respective function.
   
   Any change of tossing in a periodic VACUUM or would that throw off the
   results?
   
   
   -- 
   Rod Taylor <rbt@rbt.ca>
   
   PGP Key: http://www.rbt.ca/rbtpub.asc
   

4. Re: Win32 Powerfail testing - results

   Dave Page <dpage@vale-housing.co.uk> — 2003-02-03T19:54:15Z

    Vince Vielhaber allegedly said:
   > On Mon, 3 Feb 2003, Dave Page wrote:
   >
   >> Run | Errors Detected
   >> =============================================================
   >>  07 | COUNT CHECK - Duplicate or missing rows detected (10262)!! 09 |
   >>  DISTINCT CHECK - Duplicate or missing rows detected (9893)!!
   >>     | COUNT CHECK - Duplicate or missing rows detected (9893)!!
   >>  14 | COUNT CHECK - Duplicate or missing rows detected (10024)!!
   >
   > Out of curiousity, what was required to return things to normal
   > again?
   
   I ran the test app in reset mode which drops the table, then re-creates it
   and populates it with fresh data. I thought it best to drop first to
   eliminate possible problems with corrupt, but invisible tuples (if such a
   thing could have occured).
   Regards, Dave.
   
   
   
   

5. Re: Win32 Powerfail testing - results

   Dave Page <dpage@vale-housing.co.uk> — 2003-02-03T20:06:45Z

    Rod Taylor allegedly said:
   >> I modified the test program slightly to improve the consistency
   >> checks. The updated version is attached.
   >
   > For curiosity sake, I've compiled it and am running it on FreeBSD with
   > soft-updates enabled.
   >
   > A few variable declarations needed to be bumped up to the top of their
   > respective function.
   
   I've been doing a fair bit of C++ recently...
   
   > Any change of tossing in a periodic VACUUM or would that throw off the
   > results?
   
   Dunno, Tom could best answer that, but a *complete guess* based on piecing
   together tidbits of how it all works from various threads here, would be
   that it would merely increase the time period during which a powerfail
   would be unlikely to cause duplicate rows. Reasoning for this is that
   vacuum would be messing with tuples that are already dead.
   Please correct me if I'm wrong :-)
   
   Regards, Dave.
   
   
   
   

6. Re: Win32 Powerfail testing - results

   Tom Lane <tgl@sss.pgh.pa.us> — 2003-02-03T21:52:14Z

   "Dave Page" <dpage@vale-housing.co.uk> writes:
   >  Rod Taylor allegedly said:
   >> Any change of tossing in a periodic VACUUM or would that throw off the
   >> results?
   
   > Dunno, Tom could best answer that, but a *complete guess* based on piecing
   > together tidbits of how it all works from various threads here, would be
   > that it would merely increase the time period during which a powerfail
   > would be unlikely to cause duplicate rows. Reasoning for this is that
   > vacuum would be messing with tuples that are already dead.
   
   I think it'd be interesting to try it both ways.  VACUUM might throw in
   new failure modes.  I'm not sure if it could mask the failure mode you
   already found.
   
   			regards, tom lane
   
   

7. Re: Win32 Powerfail testing - results

   Hannu Krosing <hannu@tm.ee> — 2003-02-03T22:29:51Z

   Dave Page kirjutas E, 03.02.2003 kell 18:51:
   > Well the results are finally in. Hopefully we can concentrate on putting
   > them right, rather than having a round of "told you so's" :-)
   > 
   > I modified the test program slightly to improve the consistency checks.
   > The updated version is attached.
   > 
   > Regards, Dave.
   > 
   > System
   > ======
   > 
   > Gigabyte GA-6VTXD Motherboard
   > Dual 1GHz PIII Processors
   > 1Gb Non-ECC RAM
   > Fujitsu MPG3240AH IDE Disk Drive
   > 
   > Enhanced IDE Performance disabled in the BIOS.
   > 
   > Test
   > ====
   > 
   > Test program run from a seperate machine.
   > 20 Tests per OS.
   > Powerfail randomly applied.
   
   Your hardware should also be able to run Postgres on BeOS
   
   http://www.bebits.com/app/2752
   
   Being the only non-unix "port" before/besides win32, it could be an
   interesting excercise.
   
   You should be able to get and installable BeOS itself from SourceForge
   
   http://sourceforge.net/projects/crux/
   
   > Windows 2000 Testing
   > ====================
   
   Is this NTFS ?
   
   Any possibility of trying the same tests with SCSI disks ?
   
   > Write back cache on IDE disk disabled.
   > Clean installation of Windows 2000 Server with Service Pack 3
   > 
   > Run | Errors Detected
   > =============================================================
   >  01 | None
   >  02 | None
   >  03 | None
   >  04 | None
   >  05 | None
   >  06 | None
   >  07 | COUNT CHECK - Duplicate or missing rows detected (10262)!!
   >  08 | None
   >  09 | DISTINCT CHECK - Duplicate or missing rows detected (9893)!!
   
   I remember having problems with UNIQUE columns having duplicate values a
   few versions back on Linux-ext2-IDE. Could this be the same problem or
   must it be something completely different ?
   
   >     | COUNT CHECK - Duplicate or missing rows detected (9893)!!
   >  10 | None
   >  11 | None
   >  12 | None
   >  13 | None
   >  14 | COUNT CHECK - Duplicate or missing rows detected (10024)!!
   >  15 | None
   >  16 | None
   >  17 | None
   >  18 | None
   >  19 | None
   >  20 | None
   > 
   > Linux Testing
   > =============
   > 
   > Clean installation of Slackware Linux 8.1 on ext3
   > Kernel 2.4.18
   > 
   > Run | Errors Detected
   > =============================================================
   >  01 | None
   > ...
   >  20 | None
   
   BTW, are the tests portable enough to run also on MSSQL, Oracle and DB2
   ?
   
   I know that you can't publish exact results, but perhaps something like
   the GreatBridge results - the one that runs only on Win32 did so-and-so,
   the one that has 'i' at the end of version number this, and the one
   whose name consists of two letters and a number did that ?
   
   -- 
   Hannu Krosing <hannu@tm.ee>