On Thu, Aug 13, 2015 at 2:52 PM, Josh Elser <josh.el...@gmail.com> wrote:
> 1. Regarding the information above about accumulo tracing, if more than >> one server is listed in $ACCUMULO_HOME/conf/tracers how do the clients >> select the trace server to send their trace data to? >> > > Tracers register themselves in ZooKeepers and the client tracing libraries > know to look in ZooKeeper to find them. You as a user shouldn't have to > worry about it -- it should happen automagically for you. I wanted to know how well balanced the tracing data is processed. Is there a recommended system design with respect to the tracing servers? Should we dedicate a few nodes to being just tracing servers or is it best to have each tablet server also be a tracing server? If we make each tablet server also a tracing server will each tablet server just send its tracing data to the local tracing server? > 2. As an admin what is the best way to determine which tables have >> recently been traced? >> > > I'm not entirely sure what you mean by "[tables that have been recently > traced]". You can look at the "Recent Traces" page on the monitor to get a > list of the traces in the last X minutes. > > Many operations going on in Accumulo will be getting traced. If you have > an active system, you'll constantly see new traces for minor compactions > and major compactions. Sometimes a trace will cause very high system CPU utilization (90%) and system load on the tracing server. When this becomes detrimental to the server I would like to determine what table was being traced at that time (to get the user/developer to refine the trace).
