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From Josh Elser <josh.el...@gmail.com>
Subject Re: Planning for (eventual) removal of instance.dfs.{uri,dir}
Date Thu, 11 Dec 2014 16:30:21 GMT
To be clear -- if you want to address actual problems you've seen WRT 
compatibility, start up a new thread and we can work through the issues 
you have seen and what you are fearful of.

I'm not seeing the relevance to this discussion and don't want it to get 
derailed because dealing with the removal of the instance.dfs.* stuff is 
important for us to handle properly.

Josh Elser wrote:
> You're building functions over the location of files in HDFS? Automated
> configuration of instances?
>
> Jeremy Kepner wrote:
>> When we remove functions, do we have any official guidance to our
>> users who may
>> have built applications that use those functions?
>>
>> Right now, the official position is that the Accumulo developers can
>> remove
>> as they see fit. However, this provides no guidance to users as to what
>> they are suppose to do? As it stands, our guidance is that they have
>> the following choices:
>>
>> (0) Diligently watch the Accumulo e-mail list and aggressively weigh
>> in on
>> any vote to remove functions that may impact them.
>>
>> (1) Find someone to modify the original source code of their
>> applications,
>> build it, and *re-verify* the application. I emphasise the re-verify
>> because
>> that is usually the most costly part of the process that often won't
>> get approved
>> by management.
>>
>> (2) Don't upgrade Accumulo.
>>
>>
>>
>>
>>
>> On Thu, Dec 11, 2014 at 10:03:56AM -0500, Christopher wrote:
>>> Well, no, the database will start if we rely on instance.volumes, but we
>>> may be unable to find files that have relative paths, if we incorrectly
>>> assume /accumulo. Making it required is annoying if users don't have
>>> relative paths.
>>>
>>>
>>> --
>>> Christopher L Tubbs II
>>> http://gravatar.com/ctubbsii
>>>
>>> On Thu, Dec 11, 2014 at 8:15 AM,<dlmarion@comcast.net> wrote:
>>>
>>>> How so? If someone upgrades from another version and is using a
>>>> different
>>>> dir, doesn't specify it in the configuration, and we assume
>>>> /accumulo, then
>>>> their database won't start. The other option, which may be safer than
>>>> making any assumptions, is to make instance.volumes a required
>>>> parameter
>>>> with no defaults.
>>>>
>>>> ----- Original Message -----
>>>>
>>>> From: "Christopher"<ctubbsii@apache.org>
>>>> To: "Accumulo Dev List"<dev@accumulo.apache.org>
>>>> Sent: Wednesday, December 10, 2014 11:51:39 PM
>>>> Subject: Re: Planning for (eventual) removal of instance.dfs.{uri,dir}
>>>>
>>>> The URI is probably reasonable, but the dir is potentially
>>>> problematic if
>>>> you weren't using the default.
>>>>
>>>>
>>>> --
>>>> Christopher L Tubbs II
>>>> http://gravatar.com/ctubbsii
>>>>
>>>> On Wed, Dec 10, 2014 at 10:03 PM, dlmarion<dlmarion@comcast.net> wrote:
>>>>
>>>>> Looks like VolumeConfiguration falls back to fs.defaultFS for the
>>>>> uri and
>>>>> /accumulo for the dir. You could remove both properties and still keep
>>>> this
>>>>> as the documented default behavior if instance.volumes is not
>>>>> specified.
>>>>>
>>>>>
>>>>>
>>>>> <div>-------- Original message --------</div><div>From:
Christopher<
>>>>> ctubbsii@apache.org> </div><div>Date:12/10/2014 9:13 PM
(GMT-05:00)
>>>>> </div><div>To: Accumulo Dev List<dev@accumulo.apache.org>
>>>>> </div><div>Cc:</div><div>Subject: Re: Planning
for (eventual)
>>>>> removal of
>>>>> instance.dfs.{uri,dir}</div><div>
>>>>> </div>My ACCUMULO-2589 branch in github (
>>>>> https://github.com/ctubbsii/accumulo/tree/ACCUMULO-2589) does have a
>>>>> commit
>>>>> that drops a bunch of stuff (which may or may not be accepted as is
>>>>> for
>>>>> 2.0). The instance.dfs.{uri,dir} properties aren't so easy and require
>>>> more
>>>>> planning, because it's not just removing a property... it's also
>>>>> dealing
>>>>> with updating internal data by making relative paths absolute.
>>>>>
>>>>> For what it's worth, I'm also looking at what changes if we drop
>>>>> Hadoop 1
>>>>> support.
>>>>>
>>>>> As for the validation of config, I think we do a sanity check on
>>>>> startup
>>>>> already, which we can always extend. Doesn't solve this issue, though.
>>>>>
>>>>>
>>>>> --
>>>>> Christopher L Tubbs II
>>>>> http://gravatar.com/ctubbsii
>>>>>
>>>>> On Wed, Dec 10, 2014 at 8:59 PM, dlmarion<dlmarion@comcast.net>
wrote:
>>>>>
>>>>>> We should schedule a bunch of deprecated things for removal in 2.0
to
>>>>> ease
>>>>>> maintenance. Do we have a way to validate the site.xml and zookeeper
>>>>>> settings before startup and fail with appropriate error message.
>>>>>>
>>>>>>
>>>>>>
>>>>>> <div>-------- Original message --------</div><div>From:
Christopher<
>>>>>> ctubbsii@apache.org> </div><div>Date:12/10/2014 8:44
PM (GMT-05:00)
>>>>>> </div><div>To: Accumulo Dev List<dev@accumulo.apache.org>
>>>>>> </div><div>Cc:</div><div>Subject: Planning
for (eventual) removal of
>>>>>> instance.dfs.{uri,dir}</div><div>
>>>>>> </div>So,
>>>>>>
>>>>>> instance.volumes replaces instance.dfs.uri and instance.dfs.dir in
>>>>>> 1.6.
>>>>>> But, what's our long-term plan for these? I ask, because we still
>>>>>> have
>>>>>> internal code that uses instance.dfs.uri to resolve relative paths.
>>>>>>
>>>>>> Should we force these to be re-written at some point (maybe on
>>>>>> upgrade
>>>> to
>>>>>> 1.7)? Should we continue to support the deprecated properties
>>>>> indefinitely
>>>>>> and continue the lazy re-write-on-compact? Do we transition by
>>>> requiring
>>>>>> instance.volumes to specify the volumes, and only use the old
>>>> properties
>>>>> to
>>>>>> resolve relative paths?
>>>>>>
>>>>>> My personal view is that we should provide an upgrade-prep/check
tool
>>>>> prior
>>>>>> to upgrade to 2.0, which checks and/or re-writes paths and verifies
>>>> that
>>>>>> instance.volumes is set.
>>>>>>
>>>>>> Does anybody have a different opinion on this?
>>>>>>
>>>>>> --
>>>>>> Christopher L Tubbs II
>>>>>> http://gravatar.com/ctubbsii
>>>>>>
>>>>

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