high severitySlack Bolt JS Socket Mode (@slack/bolt, @slack/socket-mode)
Logs show repeated reconnection INFO: \"[INFO] socket-mode:SocketModeClient:0 Reconnecting to Slack ...\" followed by crash/error: \"Unhandled event 'server explicit disconnect' in state 'connecting'.\" Missed events during disconnects; app unresponsive until restart. Seen in Docker/K8s.
Root cause
@slack/socket-mode 1.x state machine design flaw causes unhandled 'server explicit disconnect' events during race conditions in reconnects after expected Slack disconnects (refresh every few hours, reasons like 'refresh_requested', 'too_many_websockets'). Hanging connections from unclean shutdowns exceed 10-connection limit, triggering loops.
slackbolt-jssocket-modereconnectionwebsocketstate-machinetoo_many_websockets