PHP - Manual: MongoDB\Driver\ReadPreference
2024-11-13
(mongodb >=1.0.0)
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.
版本 | 说明 |
---|---|
PECL mongodb 1.7.0 |
Added the
Implements Serializable. |
PECL mongodb 1.2.0 |
Added the
Implements MongoDB\BSON\Serializable. |
官方地址:https://www.php.net/manual/en/class.mongodb-driver-readpreference.php