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.
EXPLAIN REBALANCE PARTITIONS
On this page
Returns the set of steps that REBALANCE PARTITIONS would run if you executed it now.
Syntax
EXPLAIN REBALANCE PARTITIONS ON db_name
Remarks
-
db_
- name of a SingleStore database.name -
See MV_
REBALANCE_ STATUS for the column definitions in the result set.
The Ordinal is the target partition’s ordinal, and the Target_COPY PARTITION
on partitions test:1
and test:3
in parallel.Estimated_
is the estimated total time (in milliseconds) that each low-level command will take to complete.
Example
EXPLAIN REBALANCE PARTITIONS ON memsql_demo;
+-----------------------------+---------+-------------+-------------+-------+-----------------------------+
| Action | Ordinal | Target_Host | Target_Port | Phase | Estimated_Time_Remaining_Ms |
+-----------------------------+---------+-------------+-------------+-------+-----------------------------+
| COPY PARTITION | 13 | 127.0.0.1 | 10002 | 3 | 7821 |
| COPY PARTITION | 2 | 127.0.0.1 | 10003 | 4 | 7821 |
| COPY PARTITION | 2 | 127.0.0.1 | 10004 | 4 | 7821 |
| PROMOTE PARTITION WITH DROP | 2 | 127.0.0.1 | 10003 | 5 | 1351 |
| DROP PARTITION | 2 | 127.0.0.1 | 10002 | 6 | 1002 |
| DROP PARTITION | 13 | 127.0.0.1 | 10004 | 6 | 1002 |
+-----------------------------+---------+-------------+-------------+-------+-----------------------------+
Note: The Estimated_
is the estimated total time (in milliseconds) that each low-level command will take to complete.
Understanding the Rebalance Actions
Each action occurs on a single partition.
Action |
Definition |
---|---|
|
Copies a partition and sets up replication to keep the copy in sync. |
|
Promotes a replica partition into a master partition. |
|
Drops a partition. |
Last modified: May 24, 2023