Default Write Concern Change
These release notes outline a change to all driver interfaces released in November 2012. See release notes for specific drivers for additional information.
Changes
As of the releases listed below, there are two major changes to all drivers:
All drivers will add a new top-level connection class that will increase consistency for all MongoDB client interfaces.
This change is non-backward breaking: existing connection classes will remain in all drivers for a time, and will continue to operate as expected. However, those previous connection classes are now deprecated as of these releases, and will eventually be removed from the driver interfaces.
The new top-level connection class is named
MongoClient
, or similar depending on how host languages handle namespacing.The default write concern on the new
MongoClient
class will be to acknowledge all write operations [1]. This will allow your application to receive acknowledgment of all write operations.See the documentation of Write Concern for more information about write concern in MongoDB.
Please migrate to the new
MongoClient
class expeditiously.
[1] | The drivers will call getLastError without
arguments, which is logically equivalent to the w: 1 option.However, this operation allows replica set users to override
the default write concern with the
settings.getLastErrorDefaults setting in the
Self-Managed Replica Set Configuration.getLastError is removed starting in MongoDB 5.1. See
Write Concern Specification for alternatives. |
Releases
The following driver releases will include the changes outlined in Changes. See each driver's release notes for a full account of each release as well as other related driver-specific changes.
C#, version 1.7
Java, version 2.10.0
Node.js, version 1.2
Perl, version 0.501.1
Legacy PHP, version 1.4
Python, version 2.4
Ruby, version 1.8