Merge pull request #747 from Icinga:fix/performance_counter_null_values

Fix: Performance counter results sometimes reporting null instead of 0

Fixes an issue with performance counters, sometimes reporting empty values instead of at least 0

Author: LordHepipud

doc/100-General/10-Changelog.md

@@ -22,6 +22,7 @@ This beta release has reworked the entire handling on how thresholds and the che
 * [#735](https://github.com/Icinga/icinga-powershell-framework/pull/735) Fixes an issue with filter for EventLog events, which did not properly handle multiple event id includes, causing empty results
 * [#743](https://github.com/Icinga/icinga-powershell-framework/pull/743) In the REST API response header `Server`, tell the software version, not the machine name (RFC 9110)
 * [#745](https://github.com/Icinga/icinga-powershell-framework/pull/745) Fixes an issue for service provider with service names not interpreted correctly in case it contains `[]`
+* [#746](https://github.com/Icinga/icinga-powershell-framework/issues/746) Fixes an issue with performance counters, sometimes reporting empty values instead of at least 0
 
 ### Enhancements
 

lib/core/perfcounter/New-IcingaPerformanceCounterObject.psm1

@@ -82,6 +82,7 @@ function New-IcingaPerformanceCounterObject()
         # Initialise the counter
         try {
             $this.PerfCounter.NextValue() | Out-Null;
+            $this.PerfCounter.NextSample() | Out-Null;
         } catch {
             # Nothing to do here, will be handled later
         }
@@ -110,17 +111,23 @@ function New-IcingaPerformanceCounterObject()
     $pc_instance | Add-Member -MemberType ScriptMethod -Name 'Value' -Value {
         [hashtable]$CounterData = @{ };
 
+        $CounterValue = $this.PerfCounter.NextValue();
+
+        if ($null -eq $CounterValue) {
+            $CounterValue = 0;
+        }
+
         try {
             [string]$CounterType = $this.PerfCounter.CounterType;
-            $CounterData.Add('value', ([math]::Round([decimal]$this.PerfCounter.NextValue(), 6)));
+            $CounterData.Add('value', ([math]::Round([decimal]$CounterValue, 6)));
             $CounterData.Add('sample', $this.PerfCounter.NextSample());
             $CounterData.Add('help', $this.PerfCounter.CounterHelp);
             $CounterData.Add('type', $CounterType);
             $CounterData.Add('error', $null);
         } catch {
             $CounterData = @{ };
-            $CounterData.Add('value', $null);
-            $CounterData.Add('sample', $null);
+            $CounterData.Add('value', 0); # Set the value to 0 in case of an error
+            $CounterData.Add('sample', 0);
             $CounterData.Add('help', $null);
             $CounterData.Add('type', $null);
             $CounterData.Add('error', $_.Exception.Message);

lib/icinga/plugin/New-IcingaCheck.psm1

@@ -198,7 +198,7 @@ function New-IcingaCheck()
 
         [string]$LabelName      = (Format-IcingaPerfDataLabel -PerfData $this.Name);
         [string]$MultiLabelName = (Format-IcingaPerfDataLabel -PerfData $this.Name -MultiOutput);
-        $value                  = ConvertTo-Integer -Value $this.__ThresholdObject.Value -NullAsEmpty;
+        $value                  = ConvertTo-Integer -Value $this.__ThresholdObject.Value;
         $warning                = '';
         $critical               = '';