The requirements and recommendations for running the Rhino statistics-gathering tool (
rhino-stats) are as follows.
Rhino’s statistics-gathering tool (
rhino-stats) should be run only on a workstation (not a cluster node).
Impact on CPU usage
Executing the statistics client on the production cluster node is not recommended. The statistics client’s GUI can impact CPU usage, such that a cluster may drop calls. (The exact impact depends on the number of distinct parameter sets monitored, the number of simultaneous users and the sample frequency.)
The host running the
rhino-stats client requires a direct TCP connection to each of the Rhino cluster nodes it get statistics from.
Moreover, the client asks each node to create a TCP connection back to it, for the express purpose of sending it statistics data.
Therefore, any intermediary firewalls between the client host and the Rhino cluster must be configured to allow these connections.
Versions of the statistics client, before the release of Rhino 1.4.4, retrieved statistics by creating a single outgoing JMX connection to one of the cluster nodes.
This statistics-retrieval method was deprecated in favour of the newer direct-connection method, since the old method had a greater performance impact on the Rhino cluster.
The single-connection method is still available however, through the use of the
Performance implications (minimal impact)
Rhino’s statistics subsystem is designed to have minimal impact on performance. Gathering counter- or gauge-type statistics should not have any noticeable impact on CPU usage or latency. Gathering sample-type statistics is more costly, and will usually result in a 1-2% impact on CPU usage when several parameter sets are monitored.
rhino-stats includes the following options:
$ ./rhino-stats One (and only one) of -g (Start GUI), -m (Monitor Parameter Set), -l (List Available Parameter Sets) required. Available command line format: -h <argument> : hostname -p <argument> : port -u <argument> : username -w <argument> : password -D : display connection debugging messages -g : gui mode -l <argument> : query available statistics parameter sets -m <argument> : monitor a statistics parameter set on the console -s <argument> : sample period in milliseconds -i <argument> : internal polling period in milliseconds -d : display actual value in addition to deltas for counter stats -n <argument> : name a tab for display of subsequent graph configuration files -f <argument> : full path name of a saved graph configuration .xml file to redisplay -j : use JMX remote option for statistics download in place of direct statistics download -t <argument> : runtime in seconds (console mode only) -q : quiet mode - suppresses informational messages -T : disable display of timestamps (console mode only) -R : display raw timestamps (console mode only) -C : use comma separated output format (console mode only) -S : no per second conversion of counter deltas -k <argument> : number of hours samples to keep in gui mode (default=6) -r : output one row per node (console mode only) -o : write output to rolling CSV files (console mode only)