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From Tyler Hobbs <ty...@datastax.com>
Subject Re: Updates lost
Date Tue, 30 Aug 2011 04:14:19 GMT
On Mon, Aug 29, 2011 at 4:56 PM, Peter Schuller <peter.schuller@infidyne.com
> wrote:

> > If the client sleeps for a few ms at each loop, the success rate
> > increases. At 15 ms, the script always succeeds so far. Interestingly,
> > the problem seems to be sensitive to alphabetical order. Updating the
> > value from 'aaa' to 'bbb' never has problem. No pause needed.
>
> Is it possible the version of pycassa you're using does not guarantee
> that successive queries use non-identical and monotonically increasing
> timestamps?
>

By default, pycassa uses microsecond-precision timestamps.
ColumnFamily.insert() returns the timestamp used for the insert, so you
could always check that it was different.  However, I doubt that you're
getting more than one insert per microsecond, unless you have VM issues with
the system clock.

-- 
Tyler Hobbs
Software Engineer, DataStax <http://datastax.com/>
Maintainer of the pycassa <http://github.com/pycassa/pycassa> Cassandra
Python client library

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