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From Christopher <ctubb...@apache.org>
Subject Re: Namespaces & Application Classpath interplay
Date Tue, 16 Dec 2014 05:59:22 GMT
I'd imagine you can set the context classpath for the entire namespace with:

# this in the accumulo-site.xml
general.vfs.context.classpath.mycontext=jar1,jar2,jar3,etc.
and
# this in the namespace config
table.classpath.context=mycontext


--
Christopher L Tubbs II
http://gravatar.com/ctubbsii

On Mon, Dec 15, 2014 at 11:46 PM, Josh Elser <josh.elser@gmail.com> wrote:
>
> In essence, you're asking to apply some context classloader to a namespace
> and have it propagate down to each table in that namespace as opposed to
> setting it on each table? By doing so, you wouldn't have to ensure that
> each table for your logical "application" is configured with the same
> context classloader.
>
> If that's the case, +1 for the change -- nearly all of our properties
> already "delegate" in that fashion: per-table inherits from namespace which
> inherits from system. I'm a little sad if it doesn't actually already do it
> (because that means classloader configuration is an edge case internally),
> but happy that you'd like to work on it :)
>
>
> Chris Bennight wrote:
>
>> (Note - my assumption here is that I can't currently assign an isolated
>> classpath as "default" for a particular namespace;  if I missed something
>> apologies)
>>
>> So I get the ability to assign an application specific classpath on a per
>> table basis.  In my case I create (and sometimes remove) tables via the
>> API
>> (as opposed to the shell) - which scope normally mediated by a namespace.
>>
>> I can attach an application classpath at creation to each table, but this
>> requires sharing information (name of application classpath somehow
>> configured/set for application), or convention (always call it "xyz")
>> between the accumulo config and client application.
>>
>> I think a cleaner solution in this part would be to let the classpath be
>> tied through accumulo configuration to the namespace (this would also make
>> classpath isolation easier for other programs - they don't have to add in
>> hooks in the case of programatically creating tables).
>>
>> So my questions:
>> -- Is this something that is already in the works?  (I swear, I looked in
>> JIRA)
>> -- Is it a terrible idea (why?)
>> -- If it's not already done, and not a bad idea, should I create a ticket,
>> propose a design, and start coding after vetting?
>>
>> Thanks,
>> Chris
>>
>>

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