write_concern – Tools for specifying write concern

Tools for working with write concerns.

class pymongo.write_concern.WriteConcern(w=None, wtimeout=None, j=None, fsync=None)

WriteConcern

Parameters:
  • w: (integer or string) Used with replication, write operations will block until they have been replicated to the specified number or tagged set of servers. w=<integer> always includes the replica set primary (e.g. w=3 means write to the primary and wait until replicated to two secondaries). w=0 disables acknowledgement of write operations and can not be used with other write concern options.
  • wtimeout: (integer) Used in conjunction with w. Specify a value in milliseconds to control how long to wait for write propagation to complete. If replication does not complete in the given timeframe, a timeout exception is raised.
  • j: If True block until write operations have been committed to the journal. Cannot be used in combination with fsync. Prior to MongoDB 2.6 this option was ignored if the server was running without journaling. Starting with MongoDB 2.6 write operations will fail with an exception if this option is used when the server is running without journaling.
  • fsync: If True and the server is running without journaling, blocks until the server has synced all data files to disk. If the server is running with journaling, this acts the same as the j option, blocking until write operations have been committed to the journal. Cannot be used in combination with j.
acknowledged

If True write operations will wait for acknowledgement before returning.

document

The document representation of this write concern.

Note

WriteConcern is immutable. Mutating the value of document does not mutate this WriteConcern.

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