We are happy to announce that MongoDB version 4.4 has passed our tests and is generally available on the ObjectRocket platform.
What’s New in MongoDB 4.4
You can get the complete list of what is available in the MongoDB 4.4 release notes. Here are some of the updates and changes we wanted to highlight:
Sharding
Refinable Shard keys: This new feature allows users to add suffix fields to a collection shard key. Refining a shard key helps with situations where the existing shard key has poor cardinality.
Hedge Reads: With hedged reads, the mongos process can route read operations to multiple members per each queried shard and return results from the first respondent per shard.
Compound Hashed Shard Keys: This feature allows users to shard a collection using a compound shard key with a single hashed field.
You can read more about the changes related to sharded clusters here.
Replication
Resumable Initial Sync: MongoDB 4.4 will attempt to resume a failed initial sync (rather than re-initiate it) which can reduce the time for a Secondary to catch up
Minimum Oplog Retention Period: Users can specify the minimum number of hours to preserve an oplog entry, which helps to meet compliance requirements.
You can read more about the changes related to replica sets here.
Bug Fixes
As with every major version, 4.4 fixes bugs that aren’t backported. Put simply, this means that some bugs affecting older versions are fixed in 4.4 but never backported for different reasons in previous versions, like 4.2 and 4.0.
General Enhancements
Aggregation improvements: $out and $merge can output to a collection in a different database.
Compound hashed indexes: MongoDB 4.4 adds support for creating compound indexes with a single hashed field.
Hidden Indexes: MongoDB gives users the ability to hide/unhide indexes from the planner. Hiding an index can help us evaluate the database performance, before completely dropping it.
Blocking Sort Limit Increased: Its always a good idea to use an index for operations that have a sort stage. In the case, using an index is not feasible, MongoDB will perform an in-memory sort, that can use a buffer of 100MiB (was 32MiB in previous versions). Find command can now use allowDiskUse, to handle sorts that exceed the 100MiB buffer.
Namespace size increased from 120 bytes to 255 bytes, which allows longer <database>.<collection> names in your database.
You can read more about General Improvements here
What Happens Next?
Set up a call with our support team and we’ll put an upgrade plan in place that fits your needs. We can help you get ahead of potential problems, avoid unplanned maintenance, and help you figure out development updates, driver settings, and/or set up maintenance windows.