System Statistics Application

The System Statistics application in Usage Engine collects and consolidates execution information automatically. When the system is active, resource utilization and workflow processing is continuously monitored, and the statistics is saved in the internal database. Graphs can be viewed in the Desktop, DROnline, and – if installed – Grafana. 


Using the System Statistics UI, a user can select statistics for hosts, pico instances, and workflows for periods dating back two months. Available metrics: 


Pico Instance 


  • CPU User Time (%) 
  • Context Switch (/s) 
  • Swapped To Disk (blocks/s) 
  • Swapped In From Disk (blocks/s) 
  • Processes Waiting For Run (#) 
  • Processes In Sleep (#) 
  • Used Memory (bytes) 
  • Maximum Memory (bytes) 
  • Process CPU Time (%) 
  • Open File Descriptors 
  • Garbage Collection Count (#) 
  • Garbage Collection Time (ms) 
  • Thread Count (#) 
  • Throughput (/s) 
  • Queue Throughput (/s) 
  • Simultaneous (#) 
  • Queue Size (%) 

Example of Dashboard view in the Desktop: 

System Statistics Dashboard in Desktop 


The Dashboard view in DROnline, contains the following standard graphs: 

  • Pico Heap Memory Usage (%) for the last 5 minutes. 
  • Pico Process CPU Usage (%) for the last 5 minutes. 
  • Aborted Workflows. 
  • Unreachable Picos. 
  • System Log, number of messages per category and time. 
  • Pico Response Time (ms). 
  • Workflow Uptime. 
  • Workflow Throughput. 

System Statistics in WebUI 


Grafana can be used to create customized dashboards. Usage Engine includes a set of example dashboards to display System Statistics in a similar fashion to the Desktop view. Please refer to section 7.2 for more monitoring options using Grafana.