Could you please, Kevin, explain how you acheived that ? Thank you - Souheil
2010/3/4 kevin gill <ke...@movieextras.ie>: >> Hi, >> For quite some time I see messages like this in my z3.log: >> >> 2010-03-02T16:27:14 WARNING ZopePublication Competing writes/reads >> at >> /BSPSite/act/++vh++http:zis.act.at:80/bankneu/++/images/sponsor_logo.png: >> database conflict error (oid 0x063f, class BTrees.OOBTree.OOBucket, serial >> this txn started with 0x038484dc7d5ac044 2010-03-02 14:52:29.379960, >> serial >> currently committed 0x038484ff3c6b5455 2010-03-02 15:27:14.160763) >> >> I followed an advice from the zope-dev list and added some debug messages >> in >> ZODB.Connection.py where the objects are registered for writing. >> >> The following debug messages (I print the key/values of the object in >> question) occur before and after the database conflict error: >> >> ------------------- >> 2010-03-02T16:27:14 DEBUG zbsp keys: >> ['6ZZzgjNK0p.bIIlruXb4JkDo-T0J-XipPcVFGtcj0 >> LH6dMdI9akYvg', ......... , '7MmOPQOlkAHoa3T >> nydH9IIgKBqoVyn3Q.yH6OXJeLj7epObIy3M5Lg'] >> ----------- >> 2010-03-02T16:27:14 DEBUG zbsp values: [<zope.session.session.SessionData >> object at 0x43723bec>, <zope.session.session.SessionData object at >> 0x4372356c>, <zope.session.session.SessionData object at 0x437233ec>, >> ......... >> <zope.session.session.SessionData object at 0x436b586c>, >> <zope.session.session.SessionData object at 0x436b532c>, >> <zope.session.session.SessionData object at >> 0x43640b6c>,<zope.session.session.SessionData object at 0x436b572c>] >> ------------------- >> >> So it seems these are the session data containers. >> >> I wonder why they are written? Perhaps this happens when somebody else is >> logging into the system (so a new session is added) and others are >> concurrently reading from the session? However, this would mean that the >> session mechanism has a flaw, as this is a standard procedure? >> >> Any ideas of how to fix this? > > I had a serious problem with the session machinery. > > I use a very long timeout on sessions and thus have a large number of > sessions saved (up to 30k). The sweep machinery kicks in and sweeps > everything. It takes so long that all the threads do the sweep and you get > these errors. > > I customised the sweep for my site as follows: > > 1. Only sweep at night > 2. Sweep a random subset of the data (20 records), but sweep very often > 3. Different timeouts for authenticated sessions and anonymous sessions. > > Regards, > > Kevin > > >> >> Best Regards, >> Hermann >> >> -- >> herm...@qwer.tk >> GPG key ID: 299893C7 (on keyservers) >> FP: 0124 2584 8809 EF2A DBF9 4902 64B4 D16B 2998 93C7 >> _______________________________________________ >> Zope-Dev maillist - zope-...@zope.org >> https://mail.zope.org/mailman/listinfo/zope-dev >> ** No cross posts or HTML encoding! ** >> (Related lists - >> https://mail.zope.org/mailman/listinfo/zope-announce >> https://mail.zope.org/mailman/listinfo/zope ) >> >> >> > > > _______________________________________________ > Zope-Dev maillist - zope-...@zope.org > https://mail.zope.org/mailman/listinfo/zope-dev > ** No cross posts or HTML encoding! ** > (Related lists - > https://mail.zope.org/mailman/listinfo/zope-announce > https://mail.zope.org/mailman/listinfo/zope ) > _______________________________________________ Zope-Dev maillist - Zope-Dev@zope.org https://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - https://mail.zope.org/mailman/listinfo/zope-announce https://mail.zope.org/mailman/listinfo/zope )