yYCASpFxsr"></a>Different aspects of a system should be measured with different levels of granularity. For example:
                            </p>
                            <ul>
                                <li>Observing CPU load over the time span of a minute won’t reveal even quite long-lived spikes that drive high tail latencies.
                                </li>
                                <li>On the other hand, for a web service targeting no more than 9 hours aggregate downtime per yea