diff --git a/source/plugins/ruby/kubernetes_container_inventory.rb b/source/plugins/ruby/kubernetes_container_inventory.rb
index 4fe728579..ba6a9af42 100644
--- a/source/plugins/ruby/kubernetes_container_inventory.rb
+++ b/source/plugins/ruby/kubernetes_container_inventory.rb
@@ -193,25 +193,41 @@ def obtainContainerEnvironmentVars(containerId)
       $log.info("KubernetesContainerInventory::obtainContainerEnvironmentVars @ #{Time.now.utc.iso8601}")
       envValueString = ""
       begin
-        unless @@containerCGroupCache.has_key?(containerId)
+        isCGroupPidFetchRequired = false 
+        if !@@containerCGroupCache.has_key?(containerId)
+          isCGroupPidFetchRequired = true 
+        else
+          cGroupPid = @@containerCGroupCache[containerId]
+          if cGroupPid.nil? || cGroupPid.empty?            
+            isCGroupPidFetchRequired = true
+            @@containerCGroupCache.delete(containerId)
+          elsif !File.exist?("/hostfs/proc/#{cGroupPid}/environ")              
+            isCGroupPidFetchRequired = true
+            @@containerCGroupCache.delete(containerId)                       
+          end        
+        end
+
+        if isCGroupPidFetchRequired
           $log.info("KubernetesContainerInventory::obtainContainerEnvironmentVars fetching cGroup parent pid @ #{Time.now.utc.iso8601} for containerId: #{containerId}")
           Dir["/hostfs/proc/*/cgroup"].each do |filename|
             begin
-              if File.file?(filename) && File.foreach(filename).grep(/#{containerId}/).any?
+              if File.file?(filename) && File.exist?(filename) && File.foreach(filename).grep(/#{containerId}/).any?
                 # file full path is /hostfs/proc/<cGroupPid>/cgroup
-                cGroupPid = filename.split("/")[3]
-                if @@containerCGroupCache.has_key?(containerId)
-                  tempCGroupPid = @@containerCGroupCache[containerId]
-                  if tempCGroupPid > cGroupPid
+                cGroupPid = filename.split("/")[3]  
+                if is_number?(cGroupPid)                              
+                  if @@containerCGroupCache.has_key?(containerId)
+                    tempCGroupPid = @@containerCGroupCache[containerId]                  
+                    if tempCGroupPid.to_i > cGroupPid.to_i
+                      @@containerCGroupCache[containerId] = cGroupPid
+                    end
+                  else
                     @@containerCGroupCache[containerId] = cGroupPid
-                  end
-                else
-                  @@containerCGroupCache[containerId] = cGroupPid
+                  end                        
                 end
               end
-            rescue SystemCallError # ignore Error::ENOENT,Errno::ESRCH which is expected if any of the container gone while we read
-            end
-          end
+            rescue SystemCallError # ignore Error::ENOENT,Errno::ESRCH which is expected if any of the container gone while we read              
+            end          
+          end        
         end
         cGroupPid = @@containerCGroupCache[containerId]
         if !cGroupPid.nil? && !cGroupPid.empty?
@@ -341,5 +357,8 @@ def deleteCGroupCacheEntryForDeletedContainer(containerId)
         ApplicationInsightsUtility.sendExceptionTelemetry(error)
       end
     end
+    def is_number?(value)
+      true if Integer(value) rescue false
+    end
   end
 end