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From Keith Turner <ke...@deenlo.com>
Subject Re: Large numbers of authorizations
Date Fri, 23 Mar 2018 17:22:10 GMT
This is the code that scans use to filter based on column visibility
and authorizations.  It has a cache of previously seen column
visibilities and the decision that was made for those.

  https://github.com/apache/accumulo/blob/2e171cdb8420f817ff9ebeb23f9d8a70b0878ca5/core/src/main/java/org/apache/accumulo/core/iterators/system/VisibilityFilter.java

The following code does the evaluation.

  https://github.com/apache/accumulo/blob/f81a8ec7410e789d11941351d5899b8894c6a322/core/src/main/java/org/apache/accumulo/core/security/VisibilityEvaluator.java

On Fri, Mar 23, 2018 at 1:10 PM, Michael Ladakos <mdladakos@gmail.com> wrote:
>
> ---------- Forwarded message ----------
> From: Michael Ladakos <mdladakos@gmail.com>
> Date: Fri, Mar 23, 2018 at 12:32 PM
> Subject: Large numbers of authorizations
> To: user@accumulo.apache.org
>
>
> I am somewhat new to Accumulo and was doing some experimentation on
> consequences for using large numbers of authorizations.
>
> I found that a user with a large set of authorizations would take a great
> deal of time to perform a scan. I tested at various increments up to 100,000
> authorizations. At that point, it would take at least 25 seconds to perform
> the scan, even if the table was newly created with no rows.
>
> Performing a scan with a small subset of authorizations is equivalent to
> performing a query with a user that only has a small number of
> authorizations.
>
> I attempted to find the place in the code where whatever is being done,
> because I wanted to understand what caused this, but I wasn't able to track
> down the exact class. Any chance I could get an explanation or pointed in
> the right direction?
>
> Thanks!
>

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