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From aaron morton <aa...@thelastpickle.com>
Subject Re: Memtable tuning in 1.0 and higher
Date Wed, 04 Jul 2012 08:30:13 GMT
Joost, 
	Part of Jonathans explanation for flushing every approx 5 minutes was to reduce the size
of the commit log, and reduce the replay time. 

	Even with the patch flushing memtables is necessary at some point to truncate the log. If
this is an issue consider disabling durable_writes on the KS to bypass the commit log. Obviously
there are some dangers involved, but it sounds like it may be acceptable to you.

	Hope that helps. 

-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com

On 2/07/2012, at 7:43 PM, Jonathan Ellis wrote:

> I'm afraid not. It's too much change for an oldstable release series,
> and the bulk of the change is to AtomicSortedColumns which doesn't
> exist in 1.0, so even if we wanted to take a "maybe it's okay if we
> release it first in 1.1.3 and then backport" approach it wouldn't
> improve our safety margin since you'd basically need to rewrite the
> patch.
> 
> On Sun, Jul 1, 2012 at 6:40 AM, Joost Van De Wijgerd <jwijgerd@gmail.com> wrote:
>> Hi Jonathan,
>> 
>> Looks good, any chance of porting this fix to the 1.0 branch?
>> 
>> Kind regards
>> 
>> Joost
>> 
>> Sent from my iPhone
>> 
>> 
>> On 1 jul. 2012, at 09:25, Jonathan Ellis <jbellis@gmail.com> wrote:
>> 
>>> On Thu, Jun 28, 2012 at 1:39 PM, Joost van de Wijgerd
>>> <jwijgerd@gmail.com> wrote:
>>>> the currentThoughput is increased even before the data is merged into the
>>>> memtable so it is actually measuring the throughput afaik.
>>> 
>>> You're right.  I've attached a patch to
>>> https://issues.apache.org/jira/browse/CASSANDRA-4399 to fix this.
>>> 
>>> --
>>> 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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