CANCEL_DRAIN_SUBCLUSTER

Cancels the draining of a subcluster or subclusters.

Eon Mode only

Cancels the draining of a subcluster or subclusters. This function can cancel draining operations that were started by either START_DRAIN_SUBCLUSTER or the draining portion of the SHUTDOWN_WITH_DRAIN function. CANCEL_DRAIN_SUBCLUSTER marks all nodes in the designated subclusters as not draining. The previously draining nodes again accept new client connections and connections redirected from load-balancing.

This is a meta-function. You must call meta-functions in a top-level SELECT statement.

Behavior type

Volatile

Syntax

CANCEL_DRAIN_SUBCLUSTER( 'subcluster-name' )

Arguments

subcluster-name: Name of the subcluster whose draining operation to cancel. Enter an empty string to cancel the draining operation on all subclusters.

Privileges

Superuser

Examples

The following example demonstrates how to cancel a draining operation on a subcluster.

First, you can query the DRAINING_STATUS system table to view which subclusters are currently draining:


=> SELECT node_name, subcluster_name, is_draining FROM draining_status ORDER BY 1;
node_name          | subcluster_name    | is_draining
-------------------+--------------------+-------
verticadb_node0001 | default_subcluster | f
verticadb_node0002 | default_subcluster | f
verticadb_node0003 | default_subcluster | f
verticadb_node0004 | analytics          | t
verticadb_node0005 | analytics          | t
verticadb_node0006 | analytics          | t

The following function call cancels the draining of the analytics subcluster:


=> SELECT CANCEL_DRAIN_SUBCLUSTER('analytics');
             CANCEL_DRAIN_SUBCLUSTER
--------------------------------------------------------
Targeted subcluster: 'analytics'
Action: CANCEL DRAIN

(1 row)

To confirm that the subcluster is no longer draining, you can again query the DRAINING_STATUS system table:


=> SELECT node_name, subcluster_name, is_draining FROM draining_status ORDER BY 1;
node_name          | subcluster_name    | is_draining
-------------------+--------------------+-------
verticadb_node0001 | default_subcluster | f
verticadb_node0002 | default_subcluster | f
verticadb_node0003 | default_subcluster | f
verticadb_node0004 | analytics          | f
verticadb_node0005 | analytics          | f
verticadb_node0006 | analytics          | f
(6 rows)