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Replication set management

Replication set management#

bdr.create_replication_set#

This function creates a replication set.

Replication of this command is affected by DDL replication configuration including DDL filtering settings.

Synopsis#

bdr.create_replication_set(set_name name,
                           replicate_insert boolean DEFAULT true,
                           replicate_update boolean DEFAULT true,
                           replicate_delete boolean DEFAULT true,
                           replicate_truncate boolean DEFAULT true,
                           autoadd_tables boolean DEFAULT false,
                           autoadd_existing boolean DEFAULT true)

Parameters#

  • set_name — Name of the new replication set. Must be unique across the PGD group.

  • replicate_insert — Indicates whether to replicate inserts into tables in this replication set.

  • replicate_update — Indicates whether to replicate updates of tables in this replication set.

  • replicate_delete — Indicates whether to replicate deletes from tables in this replication set.

  • replicate_truncate — Indicates whether to replicate truncates of tables in this replication set.

  • autoadd_tables — Indicates whether to replicate newly created (future) tables to this replication set

  • autoadd_existing — Indicates whether to add all existing user tables to this replication set. This parameter has an effect only if autoadd_tables is set to true .

Notes#

By default, new replication sets don’t replicate DDL or PGD administration function calls. See ddl filters for how to set up DDL replication for replication sets. A preexisting DDL filter is set up for the default group replication set that replicates all DDL and admin function calls. It’s created when the group is created but can be dropped in case you don’t want the PGD group default replication set to replicate DDL or the PGD administration function calls.

This function uses the same replication mechanism as DDL statements. This means that the replication is affected by the ddl filters

configuration.

The function takes a DDL global lock.

This function is transactional. You can roll back the effects with the ROLLBACK of the transaction. The changes are visible to the current transaction.

bdr.alter_replication_set#

This function modifies the options of an existing replication set.

Replication of this command is affected by DDL replication configuration, including DDL filtering settings.

Synopsis#

bdr.alter_replication_set(set_name name,
                          replicate_insert boolean DEFAULT NULL,
                          replicate_update boolean DEFAULT NULL,
                          replicate_delete boolean DEFAULT NULL,
                          replicate_truncate boolean DEFAULT NULL,
                          autoadd_tables boolean DEFAULT NULL)

Parameters#

  • set_name — Name of an existing replication set.

  • replicate_insert — Indicates whether to replicate inserts into tables in this replication set.

  • replicate_update — Indicates whether to replicate updates of tables in this replication set.

  • replicate_delete — Indicates whether to replicate deletes from tables in this replication set.

  • replicate_truncate — Indicates whether to replicate truncates of tables in this replication set.

  • autoadd_tables — Indicates whether to add newly created (future) tables to this replication set.

Any of the options that are set to NULL (the default) remain the same as before.

Notes#

This function uses the same replication mechanism as DDL statements. This means the replication is affected by the ddl filters

configuration.

The function takes a DDL global lock.

This function is transactional. You can roll back the effects with the ROLLBACK of the transaction. The changes are visible to the current transaction.

bdr.drop_replication_set#

This function removes an existing replication set.

Replication of this command is affected by DDL replication configuration, including DDL filtering settings.

Synopsis#

bdr.drop_replication_set(set_name name)

Parameters#

  • set_name — Name of an existing replication set.

Notes#

This function uses the same replication mechanism as DDL statements. This means the replication is affected by the ddl filters

configuration.

The function takes a DDL global lock.

This function is transactional. You can roll back the effects with the ROLLBACK of the transaction. The changes are visible to the current transaction.

Warning

Don't drop a replication set that's being used by at least another node, because doing so stops replication on that node. If that happens, unsubscribe the affected node from that replication set. For the same reason, don't drop a replication set with a join operation in progress when the node being joined is a member of that replication set. Replication set membership is checked only at the beginning of the join. This happens because the information on replication set usage is local to each node, so that you can configure it on a node before it joins the group.

You can manage replication set subscription for a node using alter_node_replication_sets .

bdr.alter_node_replication_sets#

This function changes the replication sets a node publishes and is subscribed to.

Synopsis#

bdr.alter_node_replication_sets(node_name name,
                                set_names text[])

Parameters#

  • node_name — The node to modify. Currently has to be local node.

  • set_names — Array of replication sets to replicate to the specified node. An empty array results in the use of the group default replication set.

Notes#

This function is executed only on the local node and isn’t replicated in any manner.

The replication sets listed aren’t checked for existence, since this function is designed to execute before the node joins. Be careful to specify replication set names correctly to avoid errors.

This allows for calling the function not only on the node that’s part of the PGD group but also on a node that hasn’t joined any group yet. This approach limits the data synchronized during the join. However, the schema is always fully synchronized without regard to the replication sets setting. All tables are copied across, not just the ones specified in the replication set. You can drop unwanted tables by referring to the bdr.tables catalog table. These might be removed automatically in later versions of PGD. This is currently true even if the ddl filters

configuration otherwise prevent replication of DDL.

The replication sets that the node subscribes to after this call are published by the other nodes for actually replicating the changes from those nodes to the node where this function is executed.

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