Troubleshooting node resource utilization problems

Overview

The values displayed on the Administration -> Node Administration tab for memory, CPU, and disk utilization give a general indication of a node's resource usage. This information is product and platform (operating system and hardware) specific.

Application considerations

The parameters and values for the various Workbench panels can be used during application development, verification and monitoring of the node's resource usage. The general rule is that the larger the application, in terms of projects, triggers, devices, transports, listeners, etc, then the greater the use of the node's resources. The application definitions and features to review when investigating resource utilization include:

  • The number of Started triggers, the frequency of execution of the triggers.
    Using an individual project's tab
  • The execution of triggers and work items in the runtime component's Thread Pool.
    Runtime thread pool configuration
  • For Data trigger event types, the Priority (ms) parameter value controls the frequency of reading the data event variable to determine if the event condition has been met.
    Defining a Data event trigger
  • The number of triggers that have their Settings Reporting parameter set to a value other than Off.
    Trigger settings
  • The System administration > Diagnostics tab has a trigger reporting mode toggle to disable all trigger reporting. This can be used to see if the memory or CPU utilization changes when trigger reporting is disabled. If trigger reporting is impacting resource utilization in a negative manner, then all trigger settings should be reviewed and reporting set to off where not essential.
  • The number of Started devices, the size of the variables (tags, registers, coils, data blocks, user defined types, etc) in the started devices.
    Defining, viewing, and controlling devices
    Enabling per device variable security
  • The number of transports and listeners, the Connection Pool Size parameter for transports.
    Transports
    Listeners
    Connection Pool size
  • The use of transaction Mapping Logs for transports and listeners
    Mapping Logs
    Mapping Log tab
    Listener Mapping Log tab
  • The use of the Store and Forward feature of the Transaction Server
    Store & Forward tab
    Extended Transport Map Status
  • In addition to reviewing these features, review the execution characteristics of your triggers and whether there are Exceptions Log messages indicating problems with the triggers executing, problems communicating with devices, problems communicating with external enterprise applications or other application behaviors that might indicate what is happening in the system.

Your application logic (in triggers and other items) needs to be designed and implemented to recognize system conditions that may arise, such as the inability to communicate with a device or external database. This logic should be implemented in an efficient manner so that the node's resources, especially for nodes with limited system resources, are not needlessly wasted.

Application problem scenarios

Several of the sections for the individual features have a page for troubleshooting problems. Those pages contain common application problem scenarios for the feature and the steps to take to help diagnose and resolve those problems. For example: