Writing more complex rules

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In addition to numbers and keywords, you can use mathematical and Boolean operators, and you can use user-defined variables to specify rules.

  • The keywords of Predefined keywords
  • Decimal numbers
  • The mathematical operators
    +
    addition
    -
    subtraction
    *
    multiplication
    /
    division
    <
    less than
    >
    greater than
  • Parentheses ( and ) to group mathematical expressions
  • The Boolean operators
    &
    and
    |
    or
    !
    not
  • User-defined variables

    You can specify complex calculations as user-defined variables, which can then be used in expressions. User-defined variables are case-sensitive and must not match a pre-defined variable or keyword. In the configuration file, definitions for user-defined variables must precede their use in expressions.

    Variable names consist of alphanumeric characters and the underscore (_) character. An individual variable name must not exceed 128 characters. All user-defined variable names and values, in total, must not exceed 4096 characters.

Examples

  • HOTPLUG = "loadavg > onumcpus + 0.75"
  • HOTPLUG = "(loadavg > onumcpus + 0.75) & (idle < 10.0)"
  • my_idle_rate = "(cpustat.idle - cpustat.idle[5]) / (cpustat.total_ticks - cpustat.total_ticks[5])"
my_idle_percent_total = "my_idle_rate * 100 * onumcpus"
...
HOTPLUG = "(loadavg > onumcpus + 0.75) & (my_idle_percent_total < 10.0)"