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Oracle 参数 CONNECTION_BROKERS 官方解释，作用，如何配置最优化建议

本站中文解释

CONNECTION_BROKERS参数定义集群中TNS监听器之间的可用状态跟踪保持器（Connection Broker）的总数。它是控制可用状态跟踪保持器的系统参数，也可以是服务的一部分，易于SQL语句更新。

CONNECTION_BROKERS 可以用来配置默认会话路由，这里指的是在Oracle Real Application Clusters (RAC) 环境下，当用户访问特定会话时，必须指定节点 upstream 或 downstream 方向会话路由将要去往的节点。此外，CONNECTION_BROKERS 也可以用来配置在客户端/服务器环境下，当用户访问特定会话时，必须指定特定节点访问数据库会话负载均衡流量上行或下行到服务器。

正确设置CONNECTION_BROKERS参数需要根据当前环境来进行，一般情况下可以设置为预分配的最大值。

官方英文解释

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))'


数据运维技术 » Oracle 参数 CONNECTION_BROKERS 官方解释，作用，如何配置最优化建议
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