>>> [!note] Migrated issue <!-- Drupal.org comment --> <!-- Migrated from issue #2902494. --> Reported by: [larowlan](https://www.drupal.org/user/395439) >>> <h3 id="summary-problem-motivation">Problem/Motivation</h3> <p>We load nested set Node objects from the tree and then use these to inform decisions about updating the tree.<br> In a high volume environment, when multiple processes are trying to write to the tree, the left/right/depth values in the node objects may be stale by the time we get to update the nested set.</p> <h3 id="summary-proposed-resolution">Proposed resolution</h3> <p>Acquire a lock before updating.</p> <h3 id="summary-remaining-tasks">Remaining tasks</h3> <h3 id="summary-ui-changes">User interface changes</h3> <h3 id="summary-api-changes">API changes</h3> <h3 id="summary-data-model-changes">Data model changes</h3>