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From Jonathan Ellis <jbel...@gmail.com>
Subject Re: Truncate introspection
Date Mon, 27 Jun 2011 21:56:02 GMT
Each node (independently) has logic that guarantees that any writes
processed before the truncate, will be wiped out.

This does not mean that each node will wipe out the same data, or even
that each node will process the truncate (which would result in a
timedoutexception).

It also does not mean you can't have writes immediately after the
truncate that would race w/ a "truncate, check for zero sstables"
procedure.

On Mon, Jun 27, 2011 at 3:35 PM, Ethan Rowe <ethan@the-rowes.com> wrote:
> If those went to zero, it would certainly tell me something happened.  :)  I
> guess watching that would be a way of seeing something was going on.
> Is the truncate itself propagating a ring-wide marker or anything so the CF
> is logically "empty" before being physically removed?  That's the impression
> I got from the docs but it wasn't totally clear to me.
>
> On Mon, Jun 27, 2011 at 3:33 PM, Jonathan Ellis <jbellis@gmail.com> wrote:
>>
>> There's a JMX method to get the number of sstables in a CF, is that
>> what you're looking for?
>>
>> On Mon, Jun 27, 2011 at 1:04 PM, Ethan Rowe <ethan@the-rowes.com> wrote:
>> > Is there any straightforward means of seeing what's going on after
>> > issuing a
>> > truncate (on 0.7.5)?  I'm not seeing evidence that anything actually
>> > happened.  I've disabled read repair on the column family in question
>> > and
>> > don't have anything actively reading/writing at present, apart from my
>> > one-off tests to see if rows have disappeared.
>> > Thanks in advance.
>>
>>
>>
>> --
>> Jonathan Ellis
>> Project Chair, Apache Cassandra
>> co-founder of DataStax, the source for professional Cassandra support
>> http://www.datastax.com
>
>



-- 
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com

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