Custom monitor scripts use exit codes to let VCS know the status of the resource or process that is being monitored. The values that VCS expects as return values are:
1 or 100 - indicates that the resource is offline.
101 to 109 - indicates that the resource is online and has a confidence level of less than 100.
0 or 110 - indicates that the resource is online and has a confidence level of 100.
If the exit value returned is not one of the values listed above, then the status is considered unknown (typically a value of 99 is used).