Checks
Checks are defined in the [dbo].[sqlwatch_config_check] table. Code samples in this section must comply with the check_query requirement to always return a single numerical value in the @output variable. Thresholds can be set per individual requirements.
For example, a check for CPU utilisation, will always return the @output variable which will be compared to the set thresholds.
select @output=avg(pc.cntr_value_calculated)
from [dbo].[sqlwatch_logger_perf_os_performance_counters] pc
inner join [dbo].[sqlwatch_meta_performance_counter] mpc
on pc.sql_instance = mpc.sql_instance
and pc.performance_counter_id = mpc.performance_counter_id
where mpc.sql_instance = @@SERVERNAME
and object_name = 'win32_perfformatteddata_perfos_processor'
and counter_name = 'Processor Time %'
and snapshot_time > '{LAST_CHECK_DATE}'
To raise Warning when the CPU utilisation is above 60%, we will set the treshold to [check_threshold_warning] = '>60'. And to raise an Error (Critical) when it reaches 80%, we can set the critical treshold to: [check_threshold_critical] = '>80'