mongoDB v2.2.2 and pymongo v2.4 released

mongodb-2.2.2

This is a bugfix release of mongoDB, there is nothing major to note about it so just have a look at the changelog.

pymongo-2.4

Ok here’s a bigger cake we’ll have to focus on as you will have to adapt your code to use it properly. Don’t be scared, upgrading will not instantly break your current apps but…

Connection / ReplicaSetConnection deprecation

Those classes are still available and provide the old safe=False behavior meaning that by default, operations are not acknowledged. They are being replaced by MongoClient and MongoReplicaSetClient classes which on the contrary do acknowledge operations by default. So yes, now your operations will run with a safe=True by default !

Write concern

In the mongoDB talks we never hear about safe writes but about write concerns. A new API now handles these operations’ behavior such as fsync / journal committing / write acknowledgment which is in line with the internals of mongoDB. I think it’s more clear and straightforward to handle this that way so it’s a good job done by upstream even if it means we have to adapt our code for it. They come in the number of four options which are applied on a database or collection level :

  • w = integer : A value of 0 means we don’t care so it’s the fire-and-forget behavior we knew as safe=False. A value > 0 is the equivalent of the safe=True but with a more fine tuning on how many servers should confirm the operation.
  • wtimeout = integer : Adds a timeout on the w parameter.
  • j = bool : Wait until the operation has been committed to the journal.
  • fsync = bool : Wait until the database to fsync all files to disk.

 Highlights

  • Cursor can be copied with functions from the copy module
  • The set_profiling_level() method now supports a slow_ms option

See the rest in the full changelog.

 

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