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

FoundationDB Alpha 5

Language support

• FoundationDB now supports :doc:Ruby </api-ruby>

• FoundationDB now supports Node.js

• FoundationDB now supports Java </javadoc/index.html>_ and other JVM languages.

.. _alpha-5-rel-notes-features:

Features

• A new :doc:backup </backups> system allows scheduled backups of a snapshot of the FoundationDB database to an external filesystem.

• :doc:Integrated HTML documentation </index>

• :ref:Snapshot reads <snapshot isolation> allow API clients to selectively relax FoundationDB's strong isolation guarantee. Appropriate use can of them can reduce :ref:conflict-ranges but makes reasoning about concurrency harder.

• :ref:Streaming modes <streaming-mode-python> allow API clients to adjust how FoundationDB transfers data for range reads for improved performance.

• Client APIs automatically detect the appropriate network interface (local address) when connecting to a cluster, and will look for a :ref:default-cluster-file.

Compatibility

• Tuples encoded with prior alpha versions are incompatible with the tuple layer in Alpha 5.

• Databases created with Alpha 4 will be compatible. (See :ref:Upgrading from older versions <upgrading-from-older-versions> for upgrade instructions)

• Databases created before Alpha 4 will be incompatible. (See :ref:Upgrading from older versions <upgrading-from-older-versions> for details)

Changes to all APIs

• The API version has been updated to 14.

• :ref:Snapshot reads <snapshot isolation> (see :ref:Features <alpha-5-rel-notes-features>, above).

• :ref:Streaming modes <streaming-mode-python> (see :ref:Features <alpha-5-rel-notes-features>, above).

• Automatic network interface detection (see :ref:Features <alpha-5-rel-notes-features>, above).

• The tuple layer supports unicode strings (encoded as UTF-8), has a more compact encoding, and is not compatible with data from prior versions.

• Reversed range reads are now exposed through a separate parameter rather than via a negative limit.

• Extensible options are now exposed at the network, cluster, database and transaction levels. The parameters to :c:func:fdb_setup_network and :py:func:fdb.init have been replaced by network options.

• Option enumerations are available in a machine-readable format for the benefit of third-party language binding developers.

Python API changes

• :py:func:fdb.open can be called with no parameters to use the :ref:default-cluster-file.

• Waiting on a Future object has changed from .get() to :py:meth:.wait() <fdb.Future.wait>

• Reversed range reads can by specified by passing a slice object with a -1 step.

• The convenience read methods on :py:class:fdb.Database are now transactional.

C API changes

• Byte limits exposed in :c:func:fdb_transaction_get_range. These are not currently exposed by any of the higher level clients (and usually streaming modes should be preferred).

• :c:func:fdb_future_get_keyvalue_array returns an explicit flag indicating whether there is more data in the range beyond the limits passed to :c:func:fdb_transaction_get_range.

• fdb_transaction_get_range_selector has been eliminated - :c:func:fdb_transaction_get_range always takes key selectors.