/p>
                            <p>
                                <a data-type="indexterm" data-primary="dependency hierarchies" id="id-9nCjSOtmcj"></a>Google SRE has experienced only limited success with complex dependency hierarchies. We seldom use rules such as, &#34;If I know the database is slow, alert for a slow database; otherwise, alert for the website being generally slow.&#34; Dependency-reliant rules usually pertain to very stable parts of our system, such as our system for draining user traffi