Firstly. the proactive policy to ALM tree which is based on Chord DHT was extended and a back-path scheme with which each node pre-calculates a backup path for itself was proposed. When the non-leaf node leaves. all its child nodes can switch to the respective backup path immediately. https://www.bekindtopets.com/great-save-Gothic-Woman-and-Death-Moth-Butterflies-by-Sarah-Richter-Yeti-Colster-Can-Insulator-Skin-p57606-mega-find/