SHOW REBALANCE STATUS

Warning

SingleStore 9.0 gives you the opportunity to preview, evaluate, and provide feedback on new and upcoming features prior to their general availability. In the interim, SingleStore 8.9 is recommended for production workloads, which can later be upgraded to SingleStore 9.0.

Syntax

SQL

SHOW REBALANCE STATUS ON db_name

Remarks

db_name - name of a SingleStore database.
This command must be run on the master aggregator node (see Node Requirements for SingleStore Commands ).
Alternatively, you can query the information schema view MV_REBALANCE_STATUS . The following query returns the same output as the SHOW REBALANCE STATUS ON db_name command:
SQL
```
SELECT * FROM information_schema.MV_REBALANCE_STATUS
WHERE database_name = 'db_name';
```
Refer to the Permission Matrix for the required permission.

The Ordinal is the target partition’s ordinal, and the Target_Host and Target_Port correspond to the destination leaf. Any two operations in the same Phase can be run in parallel and phases are run in order. For example, the aggregator can run COPY PARTITION on partitions test:1 and test:3 in parallel. The exact meaning of what each phase means is arbitrary and depends on the particular rebalance operation. The Estimated_Time_Remaining_Ms is the estimated total time (in milliseconds) that each low-level command will take to complete.

Example

Run the following command to rebalance partitions:

SQL

REBALANCE PARTITIONS ON mydb;

View the status of REBALANCE PARTITIONS while it is still running:

SQL

SHOW REBALANCE STATUS ON mydb;

+-----------------------------------+---------+-------------+-------------+-------+-----------+--------------+-----------------------------+
| Action                            | Ordinal | Target_Host | Target_Port | Phase | Status    | Running_Time | Estimated_Time_Remaining_Ms |
+-----------------------------------+---------+-------------+-------------+-------+-----------+--------------+-----------------------------+
| COPY PARTITION                    | 13      | 127.0.0.1   | 10002       | 3     | success   | 4009         | 0                           |
| COPY PARTITION                    | 2       | 127.0.0.1   | 10003       | 4     | success   | 5109         | 0                           |
| COPY PARTITION                    | 2       | 127.0.0.1   | 10004       | 4     | success   | 5112         | 0                           |
| PROMOTE PARTITION WITH DROP FORCE | 2       | 127.0.0.1   | 10003       | 5     | running   | 405          | 1130                        |
| DROP PARTITION                    | 2       | 127.0.0.1   | 10002       | 6     | scheduled | NULL         | 1002                        |
| DROP PARTITION                    | 13      | 127.0.0.1   | 10004       | 6     | scheduled | NULL         | 1002                        |
+-----------------------------------+---------+-------------+-------------+-------+-----------+--------------+-----------------------------+

Note: The Status displays success for the activities that are already complete. The Estimated_Time_Remaining_Ms displays the estimated remaining time (in milliseconds) for each low-level command to complete.