incubator-cassandra-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Paul Loy <ketera...@gmail.com>
Subject Re: caching change between 0.7.0 and 0.7.5
Date Fri, 06 May 2011 20:30:52 GMT
Ok, thanks.

On Fri, May 6, 2011 at 8:32 PM, Jonathan Ellis <jbellis@gmail.com> wrote:

> Column objects are treated as immutable so it's quite likely you'll
> get back the same Columns (and buffers) if your query hits a local
> memtable.  This was possible in 0.7.0 as well.
>

It's funny as this was a unit test that just put a set of columns and then
read them twice, back to back. It never failed in 0.7.0, but failed first
and every run in 0.7.5.



> (This only applies to the StorageProxy interface, if you're going over
> Thrift it will do a copy over the network.)
>
> On Thu, May 5, 2011 at 12:34 PM, Paul Loy <keteracel@gmail.com> wrote:
> > Hi all,
> >
> > so I just updated Cassandra from 0.7.0 to 0.7.5. I embed Cassandra in my
> app
> > and use StorageProxy for querying.
> >
> > In one of my unit tests I write a column to Cassandra and then read it
> out
> > again twice in quick succession. The second time I now get the same
> > ByteBuffer (i.e. same id - same 'physical' HeapByteBuffer) as the first
> > call. But as I have consumed this, the position == capacity.
> >
> > I have fixed this in my code by simply using ByteBuffer#duplicate,
> however
> > I'm concerned that caching may have changed between versions and want to
> > know what the implications of that change may be.
> >
> > So my questions are:
> >
> > 1) is the Row Cache now enabled by default?
> > 2) or is there now some other form of caching that is causing this to
> happen
> > that I should be aware of?
> >
> > We're pretty close to deploying into production when we came across a
> > critical bug in 0.7.0 (infinite loop in HashMap) which means we have to
> > upgrade but I'm concerned that the changes mean our load/stress tests
> will
> > not be valid so just need some info to put my mind at ease!
> >
> > Many thanks,
> >
> > Paul.
> >
> > --
> > ---------------------------------------------
> > Paul Loy
> > paul@keteracel.com
> > http://uk.linkedin.com/in/paulloy
> >
>
>
>
> --
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of DataStax, the source for professional Cassandra support
> http://www.datastax.com
>



-- 
---------------------------------------------
Paul Loy
paul@keteracel.com
http://uk.linkedin.com/in/paulloy

Mime
View raw message