[ZODB-Dev] RelStorage and PosKey errors - is this a risky hotfix?

Anton Stonor anton at headnet.dk
Mon Jan 24 16:02:02 EST 2011


Hi there,

We have recently experienced a couple of PosKey errors with a Plone 4 site
running RelStorage 1.4.1 and Mysql 5.1.

After digging down we found that the objects that were throwing
PosKeyErrors  actually existed in the object_state table with pickles etc,
however not in the current_object table.

After inserting the missing pointers into the current_object  table,
everything worked fine:

  mysql> SELECT zoid, tid FROM object_state WHERE zoid="561701";

  +--------+--------------------+
  | zoid   | tid                |
  +--------+--------------------+
  | 561701 | 255267099158685832 |
  +--------+--------------------+

  mysql> INSERT INTO current_object(zoid, tid) VALUES('561701',
'255267099158685832');

Looks like it works -- but is this a safe way to fix PosKeyErrors?

Now, I wonder why these pointers were deleted from the current_object table
in the first place. My money is on packing -- and it might fit with the fact
that we recently ran a pack that removed an unusual large amount of
transactions in a single pack (100.000+ transactions).

But I don't know how to investigate the root cause further. Ideas?


/Anton
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mail.zope.org/pipermail/zodb-dev/attachments/20110124/17234652/attachment.html 


More information about the ZODB-Dev mailing list