mongoc_write_concern_t man page

mongoc_write_concern_t — Write Concern abstraction

Synopsis

mongoc_write_concern_t tells the driver what level of acknowledgment to await from the server. The default, MONGOC_WRITE_CONCERN_W_DEFAULT, is right for the great majority of applications.

You can specify a write concern on connection objects, database objects, collection objects, or per‐operation. Data‐modifying operations typically use the write concern of the object they operate on, and check the server response for a write concern error or write concern timeout. For example, mongoc_collection_drop_index uses the collection's write concern, and a write concern error or timeout in the response is considered a failure.

Exceptions to this principle are the generic command functions:

·
mongoc_client_command
·
mongoc_client_command_simple
·
mongoc_database_command
·
mongoc_database_command_simple
·
mongoc_collection_command
·

mongoc_collection_command_simple

These generic command functions do not automatically apply a write concern, and they do not check the server response for a write concern error or write concern timeout.

See Write Concern on the MongoDB website for more information.

Write Concern Levels

MONGOC_WRITE_CONCERN_W_DEFAULT (1)
By default, writes block awaiting acknowledgment from MongoDB. Acknowledged write concern allows clients to catch network, duplicate key, and other errors.
MONGOC_WRITE_CONCERN_W_UNACKNOWLEDGED (0)
With this write concern, MongoDB does not acknowledge the receipt of write operation. Unacknowledged is similar to errors ignored; however, mongoc attempts to receive and handle network errors when possible.
MONGOC_WRITE_CONCERN_W_MAJORITY (majority)
Block until a write has been propagated to a majority of the nodes in the replica set.
n
Block until a write has been propagated to at least n nodes in the replica set.
journal
Block until the node receiving the write has committed the journal.

Deprecation

The write concern MONGOC_WRITE_CONCERN_W_ERRORS_IGNORED (value ‐1) is a deprecated synonym for MONGOC_WRITE_CONCERN_W_UNACKNOWLEDGED (value 0), and will be removed in the next major release.

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This page is part of MongoDB C Driver. Please report any bugs at https://jira.mongodb.org/browse/CDRIVER.

Info

2016‐11‐07 MongoDB C Driver