Stress Testing

The metrics:stress Karaf Shell command can be used to simulate load on the active persistence strategy, whether it be RRDtool, JRobin, or Newts.

The tool works by generating collection sets, similar to those built when performing data collection, and sending these to the active persistence layer. By using the active persistence layer, we ensure that we use the same write path which is used by the actual data collection services.

To get started, log into the Karaf Shell on your system:

ssh -p 8101 admin@localhost

Generate samples for 10 nodes every 15 seconds and printing the statistic report every 30 seconds:

metrics:stress -n 10 -i 15 -r 30

While active, the command will continue to generate and persist collection sets. During this time you can monitor the system I/O and other relevant statistics.

When your done, use CTRL+C to stop the stress tool.

A complete list of options is available using:

metrics:stress --help

Interpreting the output

The statistics output by the tool can be be interpreted as follows:

numeric-attributes-generated

The number of numeric attributes that were sent to the persistence layer. We have no guarantee as to whether or not these were actually persisted.

string-attributes-generated

The number of string attributes that were sent to the persistence layer. We have no guarantee as to whether or not these were actually persisted.

batches

The count is used to indicate how many batches of collection sets (one at every interval) were sent to the persistence layer. The timers show how much time was spent generating the batch, and sending the batch to the persistence layer.