[ZODB-Dev] return of corruption errors

[Gerry Kirk]

Just when I thought all was fine again, running my nightly fstest.py and 
fsrefs.py is turning up errors once more on a backup copy of the db. I'm 
using the standard 'cp' to copy the db. Version of ZODB is 3.2.3.

The strange thing is, I don't get errors every night. Over the weekend, 
I had a prob one night, and next night no probs reported. Then, again 
last night:

 From fstest.py -

/backup/local/usr/local/Zope/Zeo/var/Data.fs data record exceeds 
transaction record at 607409305: tloc 1681098631 != tpos 607356807

 From fsrefs.py -
Traceback (most recent call last):
   File "fsrefs.py", line 107, in ?
     main(path)
   File "fsrefs.py", line 65, in main
     fs = FileStorage(path, read_only=1)
   File "/usr/local/Zope/SoftwareHome/lib/python/ZODB/FileStorage.py", 
line 289, in __init__
     read_only=read_only,
   File "/usr/local/Zope/SoftwareHome/lib/python/ZODB/FileStorage.py", 
line 1928, in read_index
     name, pos)
   File "/usr/local/Zope/SoftwareHome/lib/python/ZODB/FileStorage.py", 
line 179, in panic
     raise CorruptedTransactionError(message)
ZODB.FileStorage.CorruptedTransactionError:
/backup/local/usr/local/Zope/Zeo/var/Data.fs data record exceeds 
transaction record at 607409305

I tried running fsrecover.py which trimmed Data.fs from 673677466 to 
673305967. Running fstest.py and fsrefs.py on that produced errors as well.

Looking at the first error, it looks like maybe the index file is not in 
synch with the db, or just has bad data, as the db has never grown to 1.6GB.

Is it possible that the cache files are causing some of these problems? 
I posted earlier that I was having BadPickleGet and 502 response codes 
until i deleted those files.

So, I'm finding it hard to understand what is going on, since sometimes 
i have probs and sometimes it appears i don't, without any intervention. 
When I try to fix the prob with fsrecover, it still reports a prob. (sigh)

- Gerry