SingleStore DB

Addressing Orphans by Attaching New Partitions

Look at the results of SHOW CLUSTER STATUS and SHOW PARTITIONS from the previous section. We are missing a master for partition 1, but we have an online orphan for partition 1. Assuming this orphan contains data we need, we will want to attach the master:

ATTACH PARTITION x_test:1 on '127.0.0.1':10002;
SHOW CLUSTER STATUS;
+-----------+-------+----------+-----------+-------------+----------+---------+
| Host      | Port  | Database | Role      | State       | Position | Details |
+-----------+-------+----------+-----------+-------------+----------+---------+
| 127.0.0.1 | 10001 | x_test   | Reference | replicating | 0:57     |         |
| 127.0.0.1 | 10001 | x_test_0 | Master    | online      | 0:10     |         |
| 127.0.0.1 | 10001 | x_test_1 | Slave     | replicating | 0:10     |         |
| 127.0.0.1 | 10002 | x_test   | Reference | replicating | 0:57     |         |
| 127.0.0.1 | 10002 | x_test_0 | Slave     | replicating | 0:10     |         |
| 127.0.0.1 | 10002 | x_test_1 | Master    | online      | 0:10     |         |
+-----------+-------+----------+-----------+-------------+----------+---------+
SHOW PARTITIONS;
+---------+-----------+-------+--------+--------+
| Ordinal | Host      | Port  | Role   | Locked |
+---------+-----------+-------+--------+--------+
| 0       | 127.0.0.1 | 10001 | Master | 0      |
| 0       | 127.0.0.1 | 10002 | Slave  | 0      |
| 1       | 127.0.0.1 | 10001 | Slave  | 0      |
| 1       | 127.0.0.1 | 10002 | Master | 0      |
+---------+-----------+-------+--------+--------+

Warning

Do not run high level commands (REBALANCE PARTITIONS, RESTORE REDUNDANCY, DETACH LEAF, etc.) to attach the orphan into the cluster. High level commands may drop the orphan.

If your cluster has many partitions, you may want to count its partitions by role to help identify any orphaned partitions.