In the family of cgroup test there is "TestCgroupMetrics.java" which fail with some probability here and then.

The failures are more frequent on older JVMs (e.g. 8) where G1 is not a default GC yet. But the failure can be easily reproduced with G1 as well.

*How to reproduce*
Run TestCgroupMetrics.java, but modify it a bit. In method testAll() of class MetricsTestser, run "tester.testMemoryUsage();" in a loop:
```
-        tester.testMemoryUsage();
+        for (int i = 0; i < 1000; i++)
+        {
+            tester.testMemoryUsage();
+        }
```