REBALANCE_SHARDS

Rebalances shard assignments across a cluster in Eon Mode. If the current session ends, the operation immediately aborts.

Run REBALANCE_SHARDS after you modify your cluster using ALTER NODE.

Syntax

REBALANCE_SHARDS()

Privileges

Superuser

Examples

The following example rebalances the shards of all the nodes in the database:

=> SELECT REBALANCE_SHARDS();
 REBALANCE_SHARDS  
-------------------
 REBALANCED SHARDS
(1 row)

After running REBALANCE_SHARDS check the subscription status by querying the SESSION_SUBSCRIPTIONS table, for example:

=> SELECT * from session_subscriptions where is_participating='t' order by node_name, shard_name;

node_oid           | node_name  | shard_oid          |  shard_name     | is_participating
-------------------+------------+--------------------+-----------------+-----------
45035996273704978  |  node01    | 45035996273704980  | replica         | t
45035996273704978  |  node01    | 45035996273704992  | segment003      | t
45035996273705124  |  node02    | 45035996273704980  | replica         | t
45035996273705124  |  node02    | 45035996273704988  | segment002      | t
45035996273946332  |  node04    | 45035996273704984  | segment001      | t

See Also