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Subject: Re: [DISCUSSION] High-volume counters in Cassandra
From: Johan Oskarsson <johan@oskarsson.nu>
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Date: Fri, 24 Sep 2010 14:10:06 +0200
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To: dev@cassandra.apache.org

Here is an update to where we are at with the counters.

As promised we have published a new patch that adds a separate api =
method, marked experimental, for the counters in CASSANDRA-1072.

The discussion has now moved to CASSANDRA-1502, a ticket that suggests =
the internal IClock, reconciler and other classes essential for 1072 =
should be removed. Doing so would not only severely delay the addition =
of counters to Cassandra but force a grounds up redesign of 1072 that we =
believe would not improve the patch. This belief is based on the =
prototyping Kelvin did for the work that has been refined into 1072.

Since the overwhelming consensus of this discussion thread was that the =
patch is valuable to the community and worthy of going in, we feel that =
it should be committed in approximately its current form.

While we work with the Apache community to resolve this issue we=92ve =
decided to put up a temporary version of Cassandra that includes the =
counters on the Twitter Github account.
This is a step in releasing some of the systems we=92ve built on top of =
this patch to the open source community in the near future.

On 6 sep 2010, at 21.19, Jonathan Ellis wrote:

> Yes.
>=20
> On Mon, Sep 6, 2010 at 12:11 PM, Johan Oskarsson <johan@oskarsson.nu> =
wrote:
>> The consensus in this thread seems to be moving towards the following =
todos in order to get 1072 into trunk.
>>=20
>> * create separate api methods for increments
>> * mark functionality as experimental
>> * further code cleanup (please comment on jira with specific =
suggestions)
>>=20
>> Is this a reasonable summary? We'll keep this thread updated as the =
work progresses.
>>=20
>> /Johan
>>=20
>> On 6 sep 2010, at 16.47, Jonathan Ellis wrote:
>>=20
>>> On Thu, Sep 2, 2010 at 4:10 PM, Torsten Curdt <tcurdt@apache.org> =
wrote:
>>>> The feature could still be marked experimental.
>>>> That should loosen the contract a little. But at least it would be
>>>> something to work with.
>>>=20
>>> Maybe this is the best approach, post- code cleanup.  Although I'm
>>> reluctant to add code with known, significant limitations, the =
problem
>>> domain seems to be one with no silver bullets.
>>=20
>>=20
>=20
>=20
>=20
> --=20
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of Riptano, the source for professional Cassandra support
> http://riptano.com