String values may appear in the Expression or
the Thresholds text boxes. In both cases,
they must be enclosed within quotation marks. For example, the
expression for the “Slave I/O Thread Not Running”
rule is:
(%Slave_running% == "ON") && (%Slave_IO_Running% != THRESHOLD)
In similar fashion the Critical Alerts
threshold text box is set to a value of
"Yes".
When the expression is evaluated, either
"OFF" or "ON" will be
substituted for %Slave_running%, and
"Yes" or "No" for
%Slave_IO_Running%, depending on the state of
your system. If the slave is running but the I/O thread is not,
the expression then becomes:
("ON" == "ON") && ("No" != "Yes")
Without quotation marks this expression would not evaluate to
TRUE as it should.
Note
So that it is interpreted properly, the ==
operator is converted to = before being
passed to the MySQL expression parser.
