• [CHANGE] [amtool] Remove default assignment of environment variables. #2161
• [CHANGE] [PagerDuty] Enforce 512KB event size limit. #2225
• [ENHANCEMENT] [amtool] Add cluster command to show cluster and peer statuses. #2256
• [ENHANCEMENT] Add redirection from / to the routes prefix when it isn't empty. #2235
• [ENHANCEMENT] [Webhook] Add max_alerts option to limit the number of alerts included in the payload. #2274
• [ENHANCEMENT] Improve logs for API v2, notifications and clustering. #2177 #2188 #2260 #2261 #2273
• [BUGFIX] Fix child routes not inheriting their parent route's grouping when group_by: [...]. #2154
• [BUGFIX] [UI] Fix the receiver selector in the Alerts page when the receiver name contains regular expression metacharacters such as +. #2090
• [BUGFIX] Fix error message about start and end time validation. #2173
• [BUGFIX] Fix a potential race condition in dispatcher. #2208
• [BUGFIX] [API v2] Return an empty array of peers when the clustering is disabled. #2203
• [BUGFIX] Fix the registration of alertmanager_dispatcher_aggregation_groups and alertmanager_dispatcher_alert_processing_duration_seconds metrics. #2200