accumulo-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Keith Turner <>
Subject Re: visibility constraint performance
Date Thu, 09 Jun 2016 19:18:41 GMT
On Thu, Jun 9, 2016 at 2:49 PM, Jonathan Wonders <>

> Hi All,
> I've been tracking down some performance issues on a few 1.6.x
> environments and noticed some interesting and potentially undesirable
> behavior in the visibility constraint.  When the associated visibility
> evaluator checks a token to see if the user has a matching authorization,
> it uses the security operations from the tablet server's constraint
> environment which ends up authenticating the user's credentials on each
> call.  This will end up flooding logs with Audit messages corresponding to
> these authentications if the Audit logging is enabled.  It also consumes a
> non-negligible amount of CPU, produces a lot of garbage (maybe 50-60% of
> that generated under a heavy streaming ingest load), and can cause some
> contention between client pool threads when accessing the ZooCache.
> My initial measurements indicate a 25-30% decrease in ingest rate
> (entries/s and MB/s) for my environement and workload when this constraint
> is enabled.  This is with the Audit logging disabled.
> Is this intended behavior?  It seems like the authentication is redundant
> with the authentication that is performed at the beginning of the update
> session.

No. It would be best to avoid that behavior.

> Thanks,
> --Jonathan

View raw message