pd-server v3.0.1

• Fix the issue that the scheduling limit is automatically adjusted to 0 when PD schedules hot Regions #1552
• Add the enable-grpc-gateway configuration option to enable the gRPC gateway feature of etcd #1596
• Add store-balance-rate, hot-region-schedule-limit and other statistics related to scheduler configuration #1601
• Optimize the hot Region scheduling strategy and skip the Regions that lack replicas during scheduling to prevent multiple replicas from being scheduled to the same IDC #1609
• Optimize the Region merge processing logic and support giving priority to merging the Regions with smaller sizes to speed up Region merging #1613
• Adjust the default limit of hot Region scheduling in a single time to 64 to prevent too many scheduling tasks from occupying system resources and impacting performance #1616
• Optimize the Region scheduling strategy and support giving high priority to scheduling Regions in the Pending status #1617
• Fix the issue that random-merge and admin-merge-region operators cannot be added #1634
• Adjust the format of the Region key in the log to hexadecimal notation to make it easier to view #1639