[Python-bugs-list] [ python-Bugs-775414 ] bsddb3 hash craps out with threads

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Bugs item #775414, was opened at 2003-07-22 02:29
Message generated for change (Comment added) made by jhylton
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Category: Extension Modules
Group: Python 2.3
Status: Open
Resolution: None
Priority: 5
Submitted By: Tim Peters (tim_one)
Assigned to: Gregory P. Smith (greg)
Summary: bsddb3 hash craps out with threads

Initial Comment:
Richie Hindle presented something like the attached 

(hammer.py) on the spambayes-dev mailing list.  On 

Win98SE and Win2K w/ Python 2.3c1 I usually see this 

death pretty quickly:



Traceback (most recent call last):

  File "hammer.py", line 36, in ?

    main()

  File "hammer.py", line 33, in main

    hammer(db)

  File "hammer.py", line 15, in hammer

    x = db[str(int(random.random() * 100000))]

  File "C:\CODE\PYTHON\lib\bsddb\__init__.py", line 86, 

in __getitem__

    return self.db[key]

bsddb._db.DBRunRecoveryError: (-30982,

     'DB_RUNRECOVERY: Fatal error, run database 

recovery -- fatal region error detected; run recovery')



Richie also reported "illegal operation" crashes on 

Win98SE.



It's not clear whether a bsddb3 hash *can* be used 

with threads like this.  If it can't, there's a doc bug.  If it 

should be able to, there's a more serious problem.  Note 

that it looks like hashopen() always merges DB_THREAD 

into the flags, so the absence of specifying DB_THREAD 

probably isn't the problem.

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>Comment By: Jeremy Hylton (jhylton)
Date: 2003-09-12 16:46

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I'm running this test with CVS Python (built on 9/11/03) on

RH Linux 9 with bsddb 4.1.25.  I see the same error although

it takes a relatively long time to provoke -- a minute or two.



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Comment By: Tim Peters (tim_one)
Date: 2003-09-12 16:08

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Greg, any luck?  We're starting to see the same error ("fatal 

region error detected") in some ZODB tests using bsddb3, and 

that's an infinitely more complicated setup than this little 

program.  Jeremy Hylton also sees "fatal region" errors on 

Linux, in the ZODB context.

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Comment By: Gregory P. Smith (greg)
Date: 2003-08-13 23:26

Message:
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i'll try and reproduce this.

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Comment By: Richie Hindle (richiehindle)
Date: 2003-07-22 08:50

Message:
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Minor correction: I'm on Plain Old Win98, not SE.



For what it's worth, the script seems more often than not

to provoke an application error when there's background

load, and a DBRunRecoveryError when there isn't.



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