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From Thibaut Britz <thibaut.br...@trendiction.com>
Subject Re: cassandra 0.8.7 + hector 0.8.3: All Quorum reads result in writes?
Date Wed, 11 Apr 2012 17:07:28 GMT
I will disable read repair for slice requests fully (we can handle those on
the application side) until we upgrade to 1.0.8.

Thanks,
Thibaut


On Wed, Apr 11, 2012 at 7:04 PM, Jeremy Hanna <jeremy.hanna1234@gmail.com>wrote:

> I backported this to 0.8.4 and it didn't fix the problem we were seeing
> (as I outlined in my parallel post) but if it fixes it for you, then
> beautiful.  Just wanted to let you know our experience with similar
> symptoms.
>
> On Apr 11, 2012, at 11:56 AM, Thibaut Britz wrote:
>
> > Fixed in  https://issues.apache.org/jira/browse/CASSANDRA-3843
> >
> >
> >
> > On Wed, Apr 11, 2012 at 5:58 PM, Thibaut Britz <
> thibaut.britz@trendiction.com> wrote:
> > We have read repair disabled (0.0).
> >
> > Even if this would be the case, this also doesn't explain why the writes
> are executed again and again when going over the same range again and again.
> >
> > The keyspace is new, it doesn't contain any thumbstones and only 10000
> keys.
> >
> >
> >
> > On Wed, Apr 11, 2012 at 5:52 PM, R. Verlangen <robin@us2.nl> wrote:
> > Are you sure this isn't read-repair?
> http://wiki.apache.org/cassandra/ReadRepair
> >
> >
> > 2012/4/11 Thibaut Britz <thibaut.britz@trendiction.com>
> > Also executing the same multiget rangeslice query over the same range
> again will trigger the same writes again and again.
> >
> > On Wed, Apr 11, 2012 at 5:41 PM, Thibaut Britz <
> thibaut.britz@trendiction.com> wrote:
> > Hi,
> >
> > I just diagnosted this strange behavior:
> >
> > When I fetch a rangeslice through hector and set the consistency level
> to quorum, according to cfstats (and also to the output files on the hd),
> cassandra seems to execute a write request for each read I execute. The
> write count in cfstats is increased when I execute the rangeslice function
> over the same range again and again (without saving anything at all).
> >
> > If I set the consitency level to ONE, no writes are executed.
> >
> > How can I disable this? Why are the records rewritten each time, even
> though I don't want them to be rewritten?
> >
> > Thanks,
> > Thibaut.
> >
> >
> > Code:
> >                                 Keyspace ks = getConnection(cluster,
> consistencylevel);
> >
> >                               RangeSlicesQuery<String, String, V>
> rangeSlicesQuery = HFactory.createRangeSlicesQuery(ks,
> StringSerializer.get(), StringSerializer.get(), s);
> >
> >
> rangeSlicesQuery.setColumnFamily(columnFamily);
> >                               rangeSlicesQuery.setColumnNames(column);
> >
> >                               rangeSlicesQuery.setKeys(start, end);
> >                               rangeSlicesQuery.setRowCount(maxrows);
> >
> >                               QueryResult<OrderedRows<String, String,
> V>> result = rangeSlicesQuery.execute();
> >                               return result.get();
> >
> >
> >
> >
> >
> >
> >
> > --
> > With kind regards,
> >
> > Robin Verlangen
> > www.robinverlangen.nl
> >
> >
> >
>
>

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