1. Database Reference
  2. Initialization Parameters
  3. Initialization Parameters
  4. CONNECTION_BROKERS

1.49 CONNECTION_BROKERS

CONNECTION_BROKERS is used to specify connection broker types, the number of connection brokers of each type, and the maximum number of connections per broker.

Property Description

Parameter type

String

Syntax

CONNECTION_BROKERS = broker_description[,...]

Syntax

broker_description::=

((type_clause)(brokers_clause)[(broker_options)])

Syntax

type_clause::=

TYPE={ DEDICATED | EMON | POOLED }

Indicates the broker type. This is a mandatory parameter.

Syntax

brokers_clause::=

BROKERS=integer

Indicates the number of brokers of the specified type. This is a mandatory parameter. The specified integer value must be greater than or equal to 0. If set to 0, brokers will not accept new connections, but existing connections will continue as normal.

Syntax

broker_options::=

CONNECTIONS=integer

The maximum number of connections per broker. This is an optional parameter. If the specified integer value is greater than the maximum allowed for the platform, the maximum allowed for the platform is used.

Default value

The default value for the initialization parameter will contain the DEDICATED and EMON broker types. Certain types of brokers are only started when certain features are enabled, so their configuration will only apply if the broker is needed.

Modifiable

ALTER SYSTEM

Modifiable in a PDB

No

Basic

No

Oracle RAC

The same value should be set on all instances

The connection brokers are used in these cases:

  • DEDICATED brokers are used by the multiprocess and multithreaded Oracle features. See Oracle Database Concepts for more information about these features.

    DEDICATED brokers are also used when the USE_DEDICATED_BROKER initialization parameter is set to true. See "USE_DEDICATED_BROKER" for more information about the USE_DEDICATED_BROKER initialization parameter.

  • EMON brokers are used when there is a client registered for notification over 12c AQ queues. It is not on by default. See Oracle Database Advanced Queuing User's Guide for more information about AQ queues.

  • POOLED brokers are used whenever a Database Resident Connection Pooling (DRCP) pool is active. See Oracle Database Concepts for more information about DRCP pooling.

    The POOLED broker does not appear in the parameter by default. In this case, the DRCP fields are used. If you specify the POOLED broker in the parameter, then that specification will override the DRCP fields, and further attempts to set the DRCP fields will then throw an error. Oracle recommends that the parameter be used instead of the DRCP fields.

To make it easier to modify the list, individual entries are indexed using the TYPE so it is not necessary to re-specify the entire list. For example, to adjust the number of DEDICATED brokers:

alter system set connection_brokers = '((TYPE=DEDICATED)(BROKERS=2))'