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From Thibaut Britz <thibaut.br...@trendiction.com>
Subject Re: Accessing expired data
Date Tue, 03 Jan 2012 09:02:20 GMT
Thanks Sylvain!

That's exactly what I needed to know.



On Mon, Jan 2, 2012 at 12:49 PM, Sylvain Lebresne <sylvain@datastax.com>wrote:

> On Mon, Jan 2, 2012 at 11:51 AM, Thibaut Britz
> <thibaut.britz@trendiction.com> wrote:
> > Hi,
> >
> > due to a misconfiguration on our site, some parts of our data got saved
> with
> > a wrong expiration date, which expired just recently.
> >
> > How can I recover the data?
> > Is it sufficient to copy over a backup of the tables into the table
> > directory and iterate over the table (e.g. Read.ALL). Does cassandra
> return
> > expired data in this case?
>
> It won't, unless you trick the nodes by setting their clocks in the
> past. But that is
> not something I would recommend you to do (unless you do that in some
> specific
> test cluster for that purpose only).
>
> > Or will they be silently dropped? Will the
> > sstable2jason output expired data?
>
> It will (if used on sstable that contains the data obviously). In the
> sstable2json
> output, expiring columns should look like:
>  [ column_name, column_value, column_timestamp, "e", column_ttl,
> local_expiration_time ]
> where column_ttl is the ttl you've set on the column and
> local_expiration_time is a timestamp
> of when that data will expire on the node (it's a timestamp in
> milliseconds).
>
> Using this is probably the simplest way to recover from that. A fairly
> simple option could
> be to filter that output by changing the local_expiration_time to
> whatever you want and
> use that as input for json2sstable.
>
> --
> Sylvain
>
> >
> >
> > Thanks,
> > Thibaut
> >
> >
>

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