Views
| View | Description |
|---|---|
| DBA_OB_TABLE_LOCATIONS/CDB_OB_TABLE_LOCATIONS | Displays the distribution of partition replicas, including the partition details. This is one of the most commonly used views. |
| DBA_OB_LS_LOCATIONS/CDB_OB_LS_LOCATIONS | Displays the distribution of log stream (LS) replicas. |
| DBA_OB_BALANCE_JOBS/CDB_OB_BALANCE_JOBS | Displays the ongoing load balancing jobs, such as scaling jobs and partition balancing jobs. |
| DBAOB_BALANCE_JOBS_HISTORY/CDB_OB_BALANCE_JOBS_HISTORY | Displays the history of load balancing jobs. |
| DBA_OB_BALANCE_TASKS/CDB_OB_BALANCE_TASKS | Displays the ongoing LS balancing tasks, such as LS splitting tasks and LS merging tasks. |
| DBA_OB_BALANCE_TASK_HISTORY/CDB_OB_BALANCE_TASK_HISTORY | Displays the history of LS balancing tasks. |
| DBA_OB_TRANSFER_TASKS/CDB_OB_TRANSFER_TASKS | Displays the ongoing transfer tasks. |
| DBA_OB_TRANSFER_TASK_HISTORY/CDB_OB_TRANSFER_TASK_HISTORY | Displays the history of transfer tasks. |
| GV$OB_UNITS | Displays the expected distribution and persisted resources of units. |
| GV$OB_SERVERS | Displays the actual distribution and persisted resources of units on each server. |
Parameters
| Parameter | Level | Default value | Description | Affected balancing strategy |
|---|---|---|---|---|
| enable_rebalance | Tenant level | true | Specifies whether to enable load balancing. In the sys tenant, this parameter controls unit balancing. In a user tenant, this parameter controls LS balancing and partition balancing. | Intra-tenant balancing and inter-tenant balancing |
| enable_transfer | Tenant level | true | Specifies whether to enable transfer. If this parameter is set to false, all transfer actions are prohibited. If enable_rebalance is set to true and enable_transfer is set to false, a special strategy is used to achieve balancing, with the LS quantity unchanged. |
Intra-tenant balancing |
| balancer_idle_time | Tenant level | 10s | The interval at which the load balancing background thread performs a scan. | Intra-tenant balancing |
| partition_balance_schedule_interval | Tenant level | 2h | The interval for scheduling partition balancing, which starts from the point in time when the tenant is created or the cluster is restarted.
NoticeIf a cluster is already balanced, no partition balancing task will be generated even if partition balancing is scheduled. |
Partition balancing |
| server_balance_disk_tolerance_percent | Cluster level | 10 | The tolerance in percentage of disk usage at the LS level for triggering partition disk balancing. The partitions are considered balanced when the disk usage difference between each two LSs does not exceed this percentage. | Partition disk balancing |
| server_balance_cpu_mem_tolerance_percent | Cluster level | 5 | The threshold in percentage that triggers unit balancing. If the difference between the unit load on any node and the average unit load is greater than this threshold, unit balancing is triggered. The balancing is achieved when the difference between the unit load on all nodes and the average unit load is smaller than this threshold. | Unit balancing |
| server_balance_critical_disk_waterlevel | Cluster level | 80 | The disk usage threshold in percentage. Unit balancing is triggered when the disk usage exceeds this threshold. | Unit balancing |