NetXMS Support Forum

Hello,
I'm experiencing this error after implementing MTBF (Mean Time Between Failures) and MTTR (Mean Time To Repair) Calculation

This is related to the "Node availability (percentage)" DCI only (other DCIs are OK):
See attached Capture1.PNG

Here's the error msg:
See attached Capture3.PNG

Here's the line of code being referred to:
See attached Capture2.PNG

Here's the full script:
// This script calculates MTTR, MTBF and perAvailability parameters and stores them in custom attributes
// Initialize some custom attributes the first time.
// Undefined attributes are created by SetCustomAttribute function automatically
CurrentStatus = GetDCIValue($node, FindDCIByName($node, "Status"));
PreviousState = GetCustomAttribute($node, "PreviousState");
if (PreviousState == null)
{ // In the first time, previous state is null
SetCustomAttribute($node, "PreviousState", CurrentStatus);
SetCustomAttribute($node, "TimeStamp", time());   
SetCustomAttribute($node, "NumFailures", 0);
SetCustomAttribute($node, "TotalUptime", 0);
SetCustomAttribute($node, "TotalDowntime", 0);
return 100;
}

// From here the 2nd and subsequent times
NumFailures = GetCustomAttribute($node, "NumFailures");
LastTime = time() - GetCustomAttribute($node, "TimeStamp");

// Status is up
if (CurrentStatus == 0)
{
if (PreviousState != CurrentStatus)
{   // just changed to up
// update mttr
TotalDowntime = GetCustomAttribute($node, "TotalDowntime") + LastTime;
mttr = TotalDowntime / ((NumFailures == 0) ? 1 : NumFailures) / 3600;   // to prevent division by ze
SetCustomAttribute($node, "TotalDowntime", TotalDowntime);
SetCustomAttribute($node, "mttr", mttr);
}
else
{      // still up
// update mtbf
TotalUptime = GetCustomAttribute($node, "TotalUptime") + LastTime;
mtbf = TotalUptime / ((NumFailures == 0) ? 1 : NumFailures) / 3600;   // to prevent division by zero
SetCustomAttribute($node, "TotalUptime", TotalUptime);
SetCustomAttribute($node, "mtbf", mtbf);
}
}

// Status is down
if (CurrentStatus == 4)
{
if (PreviousState != CurrentStatus)
{   // just changed to down
// update mtbf
NumFailures++;
TotalUptime = GetCustomAttribute($node, "TotalUptime") + LastTime;
mtbf = TotalUptime / NumFailures / 3600;
SetCustomAttribute($node, "NumFailures", NumFailures);
SetCustomAttribute($node, "TotalUptime", TotalUptime);
SetCustomAttribute($node, "mtbf", mtbf);
}
else
{   // still down
// update mttr
TotalDowntime = GetCustomAttribute($node, "TotalDowntime") + LastTime;
mttr = TotalDowntime / NumFailures / 3600;
SetCustomAttribute($node, "TotalDowntime", TotalDowntime);
SetCustomAttribute($node, "mttr", mttr);
}
}

if (CurrentStatus == 0 || CurrentStatus == 4)
{
// Save previous state and timestamp
SetCustomAttribute($node, "PreviousState", CurrentStatus);
SetCustomAttribute($node, "TimeStamp", time());   

// perAvailability section
TotalUptime = GetCustomAttribute($node, "TotalUptime");
TotalDowntime = GetCustomAttribute($node, "TotalDowntime");
perAvailability = TotalUptime / (TotalUptime + TotalDowntime) * 100;
SetCustomAttribute($node, "perAvailability", perAvailability);

return perAvailability;
}

Appreciate any help.
Thanks