.. _4.0.4-1:

================================================================================
|PSMDB| |release|
================================================================================

:Date: |date|
:Download: `Percona website`_
:Installation: :ref:`install`

Percona announces the GA release of |PSMDB| |release| on |date|. Download the
latest version from the `Percona website`_ or the `Percona software repositories`_.

|PSMDB| is an enhanced, open source, and highly-scalable database that is a
fully-compatible, drop-in replacement for |mongodb-ce|.  It supports |mongodb|
4.0 protocols and drivers.

|PSMDB| extends the functionality of the |mongodb-ce| by including the
:ref:`inmemory` storage engine, :ref:`encrypted WiredTiger storage
engine <psmdb.data-at-rest-encryption>`, :ref:`audit logging
<audit-log>`, :ref:`External LDAP Authentication with SASL
<ext-auth>`, :ref:`hot backups <hot-backup>`, and :ref:`enhanced query
profiling <rate-limit>`. |PSMDB| requires no changes to |mongodb|
applications or code.

This release `includes all features
<https://docs.mongodb.com/manual/release-notes/4.0>`_ of |mongodb-ce|
4.0. Most notable among these are:

- `Multi-Document ACID transactions
  <https://docs.mongodb.com/manual/release-notes/4.0/#multi-document-transactions>`_
- `Type conversion through the new aggregation operators
  <https://docs.mongodb.com/manual/release-notes/4.0/#new-type-conversion-operators>`_
- `Enhancements to the Change Streams support
  <https://docs.mongodb.com/manual/release-notes/4.0/#database-and-deployment-change-streams>`_

Note that the `MMAPv1 storage engine is deprecated
<https://docs.mongodb.com/manual/release-notes/4.0/#deprecate-mmapv1>`_
in |mongodb-ce| 4.0.

In |PSMDB| |release|, *data at rest encryption* is considered **BETA**
quality. Do not use this feature in a production environment.


 
Bugs Fixed
================================================================================

- :psmdb-bug:`235`: In some cases, hot backup did not back up the
  :dir:`keydb` directory; |mongod| could crash after restore.
- :psmdb-bug:`233`: When starting |PSMDB| with WiredTiger
  encryption options but using a different storage engine, the server started
  normally and produced no warnings that these options had been ignored
- :psmdb-bug:`239`: The WiredTiger encryption was not disabled when using the
  `Percona Memory Engine
  <https://www.percona.com/doc/percona-server-for-mongodb/4.0/inmemory.html#inmemory>`_
  storage engine.
- :psmdb-bug:`241`: WiredTiger per database encryption keys were not
  purged when the database was deleted
- :psmdb-bug:`243`: A log message was added to indicate that the
  server is running with encryption
- :psmdb-bug:`245`: KeyDB’s WiredTiger logs were not properly rotated
  without restarting the server.
- :psmdb-bug:`266`: When running the server with the `directoryperdb`
  option, the user could add arbitrary collections to the ``keydb``
  directory which is designated for data encryption.

.. important::

   Due to the fix of bug :psmdb-bug:`266`, it is not possible to downgrade from
   release |release| to 3.6.8-2.0 of |PSMDB| *if using data at rest encryption*
   (it will be possible to downgrade to |PSMDB| 3.6 as soon as :psmdb-bug:`266`
   is ported to that version).

.. |release| replace:: 4.0.4-1
.. |date| replace:: December 18, 2018
.. |mongodb-ce| replace:: MongoDB 4.0 Community Edition
.. |mongodb| replace:: MongoDB

.. include:: ../.res/url.txt
.. include:: ../.res/replace.program.txt