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From Josh Elser <josh.el...@gmail.com>
Subject Re: [VOTE] ACCUMULO-3176
Date Tue, 25 Nov 2014 19:08:44 GMT
If a tl;dr helps here, Accumulo servers merge data from ZooKeeper with 
the accumulo-site.xml file to determine the "configuration". When a user 
updates the configuration, one (or potentially zero) servers will be 
aware of this change (the one who actually performed the property update).

All other servers in the Accumulo cluster get an asynchronous update. 
Presently, it is impossible to know when all servers have seen that 
asynchronous update. Additionally, it is not technically infeasible to 
implement this -- we just haven't done it.

Sean Busbey wrote:
> Sure David. All of the comments on ACCUMULO-3176 prior to Christopher's
> assertion go over the issue, where it impacts operations, and a current
> mitigation.
>
> https://issues.apache.org/jira/browse/ACCUMULO-3176
>
> On Tue, Nov 25, 2014 at 12:29 PM, David Medinets<david.medinets@gmail.com>
> wrote:
>
>> Sean, can you please provide a pointer to the discussion of race
>> conditions in property updates?
>>
>> On Tue, Nov 25, 2014 at 1:10 PM, Sean Busbey<busbey@cloudera.com>  wrote:
>>> -1
>>>
>>> This change alters our public API while not solving the underlying issue
>> of
>>> race conditions in property updates.
>>>
>>> On Tue, Nov 25, 2014 at 11:14 AM, Christopher<ctubbsii@apache.org>
>> wrote:
>>>> Committers, this is a consensus vote on whether or not to include
>> Jenna's
>>>> patch for ACCUMULO-3176 to the 1.7.0-SNAPSHOT (master) branch.
>>>>
>>>> This patch improves the table creation API with the introduction of a
>>>> NewTableConfiguration object (similar to the pattern for
>>>> BatchWriterConfig), which allows us to be flexible on improving table
>>>> creation options in the future without creating many overloaded methods
>> (as
>>>> the table creation API has been plagued by in the past). The main goal
>> of
>>>> the patch is to allow table properties to be set on a table at the time
>> of
>>>> creation, before any tablets are assigned, but it also lays the
>> foundation
>>>> for future table creation improvements. Creating initial table
>> properties
>>>> was already present in the RPC calls, but not exposed in the API. This
>> can
>>>> support a number of use cases.
>>>>
>>>> Since an objection was raised by Sean Busbey (and a veto expected), I've
>>>> initiated this vote in lieu of applying the patch under lazy consensus
>> so
>>>> that any veto votes can be justified and addressed here.
>>>>
>>>> Note: there are a few bugs in the Mock implementation of this that I've
>>>> fixed, as well as some minor deprecation warnings and javadoc
>> improvements
>>>> I'm adding, please apply your vote under the assumption that those will
>> be
>>>> fixed before it will be applied.
>>>>
>>>> Please vote in accordance with the bylaws for consensus voting.
>>>> My vote is +1.
>>>>
>>>> Thanks.
>>>>
>>>> --
>>>> Christopher L Tubbs II
>>>> http://gravatar.com/ctubbsii
>>>>
>>>
>>>
>>> --
>>> Sean
>
>
>

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