Data loss after packing in 2.6.1?
I'm not sure if this is a known bug, or if I've stumbled on something new. I've packed a 300 Mb Data.fs recently (leaving 7 days of history). Thie resulting data.fs was still biggish, so I packed it again (leaving 0 days of history). Then interesting effects started to happen: a Folder just disappeared, then appeared back for a short time, and then disappeared again after a couple of seconds. (Of course, this might have been caused by caching effects or a bug in Mozilla.) What rattles me is that fstest.py finds no errors in the Data.fs after the first pack, yet that folder is gone there. (fstest.py finds a transaction mismatch in Data.fs after the second pack, and fsrecover.py discards absolutely all data from it.) Is this a known issue? I do not think there were any Undo records involved, and I'd expect fstest.py to barf if there were any dangling backpointers, so I suspect collector issue 875 does not apply here. (I use fstest.py from Zope-2.6.1-src, not a CVS version.) Another question: is there a command line tool that given a path to Data.fs and a location in it would produce a .zexp or .xml of an object at that location? Marius Gedminas -- Codeworks is available for Zope consulting -- http://www.codeworks.lt/
Marius Gedminas wrote:
I'm not sure if this is a known bug, or if I've stumbled on something new. I've packed a 300 Mb Data.fs recently (leaving 7 days of history). Thie resulting data.fs was still biggish, so I packed it again (leaving 0 days of history). Then interesting effects started to happen: a Folder just disappeared, then appeared back for a short time, and then disappeared again after a couple of seconds. (Of course, this might have been caused by caching effects or a bug in Mozilla.)
That's what happened to me for 2 times... Objects simply disappeared after packing (they are appeared for a short time too in one case, before they definitivly disappeared). Do you use ZEO?
Is this a known issue? I do not think there were any Undo records involved, and I'd expect fstest.py to barf if there were any dangling backpointers, so I suspect collector issue 875 does not apply here. (I use fstest.py from Zope-2.6.1-src, not a CVS version.)
Please add it to Collector 875. The ZODB-Gurus should decide if it's related or not. And I'll hope they'll hurry up...:) Cheers, Maik
Maik Jablonski wrote at 2003-5-12 14:33 +0200:
Marius Gedminas wrote:
I'm not sure if this is a known bug, or if I've stumbled on something new. I've packed a 300 Mb Data.fs recently (leaving 7 days of history). Thie resulting data.fs was still biggish, so I packed it again (leaving 0 days of history). Then interesting effects started to happen: a Folder just disappeared, then appeared back for a short time, and then disappeared again after a couple of seconds. (Of course, this might have been caused by caching effects or a bug in Mozilla.)
That's what happened to me for 2 times... Objects simply disappeared after packing (they are appeared for a short time too in one case, before they definitivly disappeared).
The reappearing might be ZEO (or more precisely ZEO client cache) related. Packing is not expected to loose or modify any data. Therefore, no cache invalidation messages are issued. When "pack" looses data, it may still be in the ZEO client cache and served thereof. After a restart of the ZEO client, the object will be dropped from the cache as the client verifies the validity of its cache entries with the server. One of my colleagues reported (now twice) dangling ZODB references. As he heavily packs, this might be pack related. I did not yet investigate his problem, but maybe, I should... Dieter
On Mon, May 12, 2003 at 02:33:43PM +0200, Maik Jablonski wrote:
Marius Gedminas wrote:
I'm not sure if this is a known bug, or if I've stumbled on something new. I've packed a 300 Mb Data.fs recently (leaving 7 days of history). Thie resulting data.fs was still biggish, so I packed it again (leaving 0 days of history). Then interesting effects started to happen: a Folder just disappeared, then appeared back for a short time, and then disappeared again after a couple of seconds. (Of course, this might have been caused by caching effects or a bug in Mozilla.)
That's what happened to me for 2 times... Objects simply disappeared after packing (they are appeared for a short time too in one case, before they definitivly disappeared).
Do you use ZEO?
No. Marius Gedminas -- Codeworks is available for Zope consulting -- http://www.codeworks.lt/
Marius Gedminas wrote:
That's what happened to me for 2 times... Objects simply disappeared after packing (they are appeared for a short time too in one case, before they definitivly disappeared).
Do you use ZEO?
No.
What happens if you try a CVS checkout of the Zope-2_6 branch? cheers, Chris
On Mon, May 19, 2003 at 10:33:39AM +0100, Chris Withers wrote:
Marius Gedminas wrote:
That's what happened to me for 2 times... Objects simply disappeared after packing (they are appeared for a short time too in one case, before they definitivly disappeared).
Do you use ZEO?
No.
What happens if you try a CVS checkout of the Zope-2_6 branch?
I'm a bit pressed on time at the moment, I'll try to take a look at it later. BTW is there a command-line tool for packing FileStorages? It would help automate the testing process a bit. Marius Gedminas -- Codeworks is available for Zope consulting -- http://www.codeworks.lt/
participants (4)
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Chris Withers -
Dieter Maurer -
Maik Jablonski -
Marius Gedminas