Re: Potential replica message file corruption/replacement

From: David Carter (no email)
Date: Fri Feb 16 2007 - 05:39:30 EST

  • Next message: Ramprasad: "cyrus not able to delete files after migration"

    On Fri, 16 Feb 2007, Bron Gondwana wrote:

    > Looks innocent, doesn't it...

    Mea culpa (and a definite "Argh, how did I miss _that_" when it was
    pointed out to me yesterday).

    > I would advise anyone who has been using replication for any length of
    > time to undertake an audit of the files on their replicas to ensure that
    > none of them have been replaced by this, because if you need to "fail
    > over" you could present users with emails that are not their own. A
    > simple size check will find almost all cases, compare what the imapd
    > returns for rfc822.size with the size of the file on disk. If you want
    > to get fancy - compute the sha1 or similar of the file at each end and
    > compare that.

    This incident underlines the need for automated sanity checks. People
    shouldn't just blindly trust the replication system.

    I generate (and constantly regenerate) checksums for message bodies and
    cache entries. On four occasions this has picked up oddities which in
    hindsight were obviously this bug.

    -- 
    David Carter                             Email: 
    University Computing Service,            Phone: (01223) 334502
    New Museums Site, Pembroke Street,       Fax:   (01223) 334679
    Cambridge UK. CB2 3QH.
    ----
    Cyrus Home Page: http://cyrusimap.web.cmu.edu/
    Cyrus Wiki/FAQ: http://cyrusimap.web.cmu.edu/twiki
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  • Next message: Ramprasad: "cyrus not able to delete files after migration"





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