Restart the cluster nodes

This page is the entry point for restarts and recovery when nodes are managed directly (systemd, bare metal, or VMs). In PXC 8.4, Clone SST (wsrep_sst_method=clone) is the default rejoin path—set it once and most restarts are “clear port/process, start the service, let Clone run.” For Kubernetes, use the Percona Operator for MySQL (PXC-based); it automates bootstrap and recovery. For full-cluster down (all nodes stopped, bootstrap from scratch), see Crash recovery.

Which problem do you have?

Scenario	Topic
Nodes are up but traffic is blocked — Cluster accepts connections but refuses every SQL query (WSREP has not yet prepared node for application use). Quorum or primary component lost.	Emergency quorum recovery
Nodes refuse to join — Joiner won’t sync, SST/Clone fails, or node never reaches Synced.	SST/Clone failure recovery
Environmental blockers — AppArmor, systemd killing the process mid-SST, or firewalls blocking SST/GCOMM.	Environmental blockers

Each topic is a separate page with step-by-step procedures. Start with the one that matches your situation; the pages cross-link where needed (for example, SST/Clone failure recovery points to Environmental blockers when the cause is AppArmor or systemd).