############# Release Notes #############

4.1.1

Fixes

Significantly improved cluster performance in a wide variety of machine failure scenarios.

Clients can now load multiple versions of the client library, and will gracefully switch to the appropriate version when the server is upgraded.
A new operating mode for fdbbackup writes backup data files into the blob store.
Transactions no longer automatically reset after a successful commit.
Added ability to set network options with environment variables.
Added a new API function for determining the value to which atomic versionstamp operations in a transaction were transformed or would have been transformed.
Improved logic for integrating manually-assigned machine classes with other constraints on role locations.
Added a new machine class stateless which is the top priority location for resolvers, proxies, and masters.
Added a new machine class log which is the top priority location for transaction logs.
Trace events are now event metrics that are exposed in Scope.

A log could attempt to recover from a partially recovered set of logs when fast recovery was enabled.
A rare scenario could cause a crash when a master is recovering metadata from the previous generation of logs.
Streaming mode EXACT was ignoring the target_bytes parameter.

API version updated to 410. See the :ref:API version upgrade guide <api-version-upgrade-guide-410> for upgrade details.