Php/docs/class.mongodb-driver-readpreference

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(mongodb >=1.0.0)

类摘要


final MongoDB\Driver\ReadPreference implements MongoDB\BSON\Serializable , Serializable {

/* Constants */

const int RP_PRIMARY = 1

const int RP_PRIMARY_PREFERRED = 5

const int RP_SECONDARY = 2

const int RP_SECONDARY_PREFERRED = 6

const int RP_NEAREST = 10

const string PRIMARY = primary

const string PRIMARY_PREFERRED = primaryPreferred

const string SECONDARY = secondary

const string SECONDARY_PREFERRED = secondaryPreferred

const string NEAREST = nearest

const int NO_MAX_STALENESS = -1

const int SMALLEST_MAX_STALENESS_SECONDS = 90

/* 方法 */

final public bsonSerialize ( ) : object

final public __construct ( string|int $mode [, array $tagSets = null [, array $options = array() ]] )

final public getHedge ( ) : object|null

final public getMaxStalenessSeconds ( ) : int

final public getMode ( ) : int

final public getModeString ( ) : string

final public getTagSets ( ) : array

final public serialize ( ) : string

final public unserialize ( string $serialized ) : void

}

预定义常量

MongoDB\Driver\ReadPreference::RP_PRIMARY
All operations read from the current replica set primary. This is the default read preference for MongoDB.
MongoDB\Driver\ReadPreference::RP_PRIMARY_PREFERRED
In most situations, operations read from the primary but if it is unavailable, operations read from secondary members.
MongoDB\Driver\ReadPreference::RP_SECONDARY
All operations read from the secondary members of the replica set.
MongoDB\Driver\ReadPreference::RP_SECONDARY_PREFERRED
In most situations, operations read from secondary members but if no secondary members are available, operations read from the primary.
MongoDB\Driver\ReadPreference::RP_NEAREST
Operations read from member of the replica set with the least network latency, irrespective of the member's type.
MongoDB\Driver\ReadPreference::PRIMARY
All operations read from the current replica set primary. This is the default read preference for MongoDB.
MongoDB\Driver\ReadPreference::PRIMARY_PREFERRED
In most situations, operations read from the primary but if it is unavailable, operations read from secondary members.
MongoDB\Driver\ReadPreference::SECONDARY
All operations read from the secondary members of the replica set.
MongoDB\Driver\ReadPreference::SECONDARY_PREFERRED
In most situations, operations read from secondary members but if no secondary members are available, operations read from the primary.
MongoDB\Driver\ReadPreference::NEAREST
Operations read from member of the replica set with the least network latency, irrespective of the member's type.
MongoDB\Driver\ReadPreference::NO_MAX_STALENESS
The default value for the "maxStalenessSeconds" option is to specify no limit on maximum staleness, which means that the driver will not consider a secondary's lag when choosing where to direct a read operation.
MongoDB\Driver\ReadPreference::SMALLEST_MAX_STALENESS_SECONDS
The minimum value for the "maxStalenessSeconds" option is 90 seconds. The driver estimates secondaries' staleness by periodically checking the latest write date of each replica set member. Since these checks are infrequent, the staleness estimate is coarse. Thus, the driver cannot enforce a max staleness value of less than 90 seconds.


更新日志

版本 说明
PECL mongodb 1.7.0

Added the MongoDB\Driver\ReadPreference::PRIMARY, MongoDB\Driver\ReadPreference::PRIMARY_PREFERRED, MongoDB\Driver\ReadPreference::SECONDARY, MongoDB\Driver\ReadPreference::SECONDARY_PREFERRED, MongoDB\Driver\ReadPreference::NEAREST constants.

Implements Serializable.

PECL mongodb 1.2.0

Added the MongoDB\Driver\ReadPreference::NO_MAX_STALENESS and MongoDB\Driver\ReadPreference::SMALLEST_MAX_STALENESS_SECONDS constants.

Implements MongoDB\BSON\Serializable.


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