MongoCommandCursor::setReadPreference
(PECL mongo >=1.6.0)
MongoCommandCursor::setReadPreference — Set the read preference for this command
説明
public MongoCommandCursor::setReadPreference
( string $read_preference
[, array $tags
] ) : MongoCommandCursor
パラメータ
read_preference
- 読み込みの優先モード。
MongoClient::RP_PRIMARY
、MongoClient::RP_PRIMARY_PREFERRED
、MongoClient::RP_SECONDARY
、MongoClient::RP_SECONDARY_PREFERRED
あるいはMongoClient::RP_NEAREST
のいずれか。 tags
- ゼロ個以上のタグセットの配列。各タグセット自体も配列で、レプリカセットのメンバーのタグにマッチさせる条件として使います。
返り値
Returns this cursor.
エラー / 例外
パラメータが無効な場合、あるいは優先読み込みモードが MongoClient::RP_PRIMARY
のときにタグセットを指定した場合に E_WARNING
が発生します。
例
例1 MongoCommandCursor::setReadPreference() tag set array syntax example
<?php$m = new MongoClient('mongodb://rs1.example.com:27017', array('replicaSet' => 'myReplSetName'));$collection = $m->selectCollection('test', 'people');$cursor = $collection->aggregateCursor( [ [ '$group' => [ '_id' => '$name', 'points' => [ '$sum' => '$points' ] ] ], [ '$sort' => [ 'points' => -1 ] ],] );// Prefer the nearest server in the "east" data center also used for reporting,// but fall back to a server in the "west" data center$cursor->setReadPreference(MongoClient::RP_NEAREST, [ [ 'dc' => 'east', 'use' => 'reporting' ], [ 'dc' => 'west' ],] );foreach ($cursor as $person) { // ...}// If the read preference is changed, it will be used the next time the cursor// is rewound and the command is re-executed.$cursor->setReadPreference(MongoClient::RP_PRIMARY);foreach ($cursor as $person) { // ...}?>
参考
- The read preferences documentation.
- MongoCommandCursor::getReadPreference() - Get the read preference for this command
- MongoCursorInterface::setReadPreference() - Set the read preference for this query