@Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    SystemMemoryStatistics that = (SystemMemoryStatistics) o;

    return physicalMemoryBytes == that.physicalMemoryBytes;

  }
The physical memory used by the Samza container process (native + on heap) in bytes.
samza-core/src/main/java/org/apache/samza/container/host/SystemMemoryStatistics.java