.. Licensed under the Apache License, Version 2.0 (the "License"); you may not
.. use this file except in compliance with the License. You may obtain a copy of
.. the License at
..
..   http://www.apache.org/licenses/LICENSE-2.0
..
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.. distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
.. WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
.. License for the specific language governing permissions and limitations under
.. the License.

.. _release/3.2.x:

============
3.2.x Branch
============

.. contents::
    :depth: 1
    :local:

.. _release/3.2.1:

Version 3.2.1
=============

Features and Enhancements
-------------------------

* :ghissue:`3746`: ``couch_icu_driver`` collation driver has been
  removed. ICU collation functionality is consolidated in the single
  ``couch_ejson_compare`` module. View performance might slighty
  increase as there are less corner cases when the C collation driver
  fails and falls back to Erlang.

* :ghissue:`3787`: Update sequences generated from DB info and
  ``_changes?since=now&limit=0`` now contain shard uuids as part of
  their internal, opaque, representation. As a result, there should be
  less chance of experiencing changes feed rewinds with these
  sequences.

* :ghissue:`3798`: ICU driver and collator algorithm versions are
  returned in the ``_node/$node/_versions`` result.

* :ghissue:`3801`: Users with the ``_metrics`` role can now read
  ``_prometheus`` metrics.

Bugfixes
--------

* :ghissue:`3780`: Avoid changes feed rewinds after shard moves.

* :ghissue:`3779`, :ghissue:`3785`: Prevent deleted view file cleanup
  from crashing when database is deleted while the cleanup process is
  running.

* :ghissue:`3789`: Fix ``badarith`` 500 errors when ``[fabric]
  request_timeout`` is set to ``infinity``.

* :ghissue:`3786`: Fix off-by-one ``limit`` error for
  ``_all_dbs``. Also, the auto-injected shard ``_dbs`` design doc is
  removed and replaced with an Erlang module.

* :ghissue:`3788`: Minimize changes feeds rewinds when a node is down.

* :ghissue:`3807`: Enable ``custodian`` application
  reporting. Previously, ``custodian`` was accidentally left disabled
  as it used a hard-coded shards db name different than ``_dbs``.

* :ghissue:`3805`: Cluster setup correctly syncs admin passwords and
  uses the new (since 3.2.0) ``[chttpd_auth]`` config section instead
  of the previous ``[couch_httpd_auth]`` section.

* :ghissue:`3810`: Local development ``dev/run`` script now uses the
  ``[chttpd_auth]`` section in ``local.ini`` instead of
  ``[couch_httpd_auth]``.

* :ghissue:`3773`: Fix reduce view collation results for unicode
  equivalent keys.

.. _release/3.2.0:

Version 3.2.0
=============

Features and Enhancements
-------------------------

* :ghissue:`3364`: CouchDB's replicator now implements a Fair Share replication
  scheduler. Rather than using a round-robin scheduling mechanism, this update allows
  specifying the relative priority of jobs via different ``_replicator`` databases.
  More information is available in the :ref:`_replicator DB docs <replicator>`.

.. figure:: ../../images/fair-enough.png
  :align: center
  :alt: Robert Downey, Jr., thinks that's fair enough for him.

* :ghissue:`3166`: Allow custom JWT claims for roles, via the ``[jwt_auth]
  roles_claim_name`` config setting.

* :ghissue:`3296`, :ghissue:`3312`: CouchDB now includes ``weatherreport`` and its
  dependency ``custodian``, a diagnostic app forked from Basho's ``riaknostic`` tool.
  More documentation is available in the :ref:`Cluster Troubleshooting
  <cluster/troubleshooting>` section.

* :ghissue:`2911`, :ghissue:`3298`, :ghissue:`3425`: CouchDB now returns the version of
  SpiderMonkey to administrators in the ``GET /_node/{node-name}/_versions`` response.

* :ghissue:`3303`: CouchDB now treats a ``408`` response received by the replicator
  similar to any ``5xx`` error (by retrying, as opposed to a permanent error). CouchDB
  will never return a ``408``, but some reverse proxies in front of CouchDB may return
  this code.

* :ghissue:`3322`: ``_session`` now accepts gzip encoding.

* :ghissue:`3254`: The new ``$keyMapMatch`` operator allows Mango to query on the keys
  of a map. It is similar to the ``$elemMatch`` operator, but instead of operating on
  the elements of array, it operates on the keys of a map.

* :ghissue:`3336`: Developers now have access to a ``.devcontainer`` configuration for
  the 3.x version of CouchDB, right in the source code repository.

* :ghissue:`3347`: The default maximum attachment size has been reduced from
  ``infinity`` to 1 GiB.

* :ghissue:`3361`: Compaction process suspension now appears in the ``active_tasks``
  output, allowing administrators to verify that the ``strict_window`` value is being
  respected.

* :ghissue:`3378`: The ``[admins]`` section and the ``[replicator] password`` are now
  redacted from all logs. In addition, :ghissue:`3380` removes user credentials,
  user documents and design documents from logfiles as much as possible. Further,
  :ghissue:`3489` no longer logs all of the messages received by a terminated internal
  Erlang process.

* :ghissue:`3421`, :ghissue:`3500`: CouchDB now supports SpiderMonkey 78 and 86.

* :ghissue:`3422`: CouchDB now supports Erlang/OTP 23 and ``error_logger`` reports
  for Erlang/OTP >= 21.

* :ghissue:`3566`: CouchDB now also supports Erlang/OTP 24.

* :ghissue:`3571`: CouchDB *no longer supports Erlang/OTP 19*.

* :ghissue:`3643`: Contribute a custom Erlang network protocol to CouchDB,
  users can specify nodes to use TCP or TLS.

.. figure:: ../../images/TLS-Handshake.png
  :align: center
  :alt: The SSL/TLS handshake enables the TLS client and server to establish
        the secret keys with which they communicate.

* :ghissue:`3472`, :ghissue:`3473`, :ghissue:`3609`: Migrate some config options from
  ``[httpd]`` to ``[chttpd]``, migrate some from ``[couch_httpd_auth]`` to
  ``[chttpd_auth]``, and comment all out in the ``default.ini``.

  * Config options moved from ``[httpd]`` to ``[chttpd]``:
    ``allow_jsonp``, ``changes_timeout``, ``config_whitelist``,
    ``enable_cors``, ``secure_rewrites``, ``x_forwarded_host``,
    ``x_forwarded_proto``, ``x_forwarded_ssl``,
    ``enable_xframe_options``, ``max_http_request_size``.

  * Config options moved from ``[couch_httpd_auth]`` to ``[chttpd_auth]``:
    ``authentication_redirect``, ``require_valid_user``, ``timeout``, ``auth_cache_size``,
    ``allow_persistent_cookies``, ``iterations``, ``min_iterations``, ``max_iterations``,
    ``password_scheme``, ``proxy_use_secret``, ``public_fields``, ``secret``,
    ``users_db_public``, ``x_auth_roles``, ``x_auth_token``, ``x_auth_username``,
    ``cookie_domain``, ``same_site``

* :ghissue:`3586`: We added a new way of specifying basic auth credentials
  which can include various characters previously not allowed to be included
  in the url info part of endpoint urls.

* :ghissue:`3483`: We added a way of specifying requirements for new user passwords
  using a list of regular expressions.

* :ghissue:`3506`, :ghissue:`3416`, :ghissue:`3377`: CouchDB now provides a Prometheus
  compatible endpoint at ``GET /_node/{node-name}/_prometheus``. A configuration option
  allows for scraping via a different port (17986) that does not require authentication,
  if desired. More information is available at the :ref:`Prometheus API endpoint
  <api/server/prometheus>` summary.

* :ghissue:`3697`, :issue:`883` (JIRA): As an opt-in policy, CouchDB can now stop
  encoding the plus sign ``+`` in non-query parts of URLs, in compliance with the
  original CouchDB standards. The opt-in is via the ``[chttpd] decode_plus_to_space =
  true`` setting. *In CouchDB 4.x, this is going to be an opt-out policy.*

* :ghissue:`3724`: CouchDB now has new CSP settings for attachments and show/list
  functions. This deprecates the old ``[csp] enable`` and ``[csp] header_value``
  settings, replacing them with the new ``[csp] utils_enable`` and ``[csp]
  utils_header_value`` settings respectively. In addition, new settings for
  ``attachments_enable``, ``attachments_header_value``, ``showlist_enable`` and
  ``showlist_header_value`` now are available. Documentation is in the ``default.ini``
  file.

* :ghissue:`3734`, :ghissue:`3733`: Users with databases that have low ``q`` and ``n``
  values would often receive the ``No DB shards could be opened`` error when the cluster
  is overloaded, due to a hard-coded 100ms timeout. CouchDB now calculates a more
  reasonable timeout, based on the number of shards and the overall maximum fabric
  request timeout limit, using a geometric series.

Performance
-----------

* :ghissue:`3337`: Developer nodes now start faster when using the ``dev/run`` script.

* :ghissue:`3366`: The monolithic ``couch_server`` process has been sharded for
  performance. Previously, as a single ``gen_server``, the process would
  have a finite throughput that, in busy clusters, is easily breached -- causing a
  sizeable backlog in the message queue, ultimately leading to failure and errors. No
  more! The aggregate message queue info is still available in the ``_system`` output.
  ( :ghissue:`3370` )

* :ghissue:`3208`: CouchDB now uses the latest ibrowse 4.4.2 client for the replicator.

* :ghissue:`3600`, :ghissue:`3047`, :ghissue:`3019`: The default ``slack`` channel for
  smoosh auto-compaction has been increased to a more reasonable value, reducing load
  on systems that would have normally been idle in CouchDB 2.x (where no auto-compaction
  daemon exists).

* :ghissue:`3711`: Changes feeds may no longer rewind after shard moves, assuming the
  node and range specified by the changes feed nonce can still match an existing node's
  shard.

Bugfixes
--------

* Complete retirement of the JavaScript test suite - replaced by Elixir. Hooray!
* :ghissue:`3165`: Allow configurability of JWT claims that require a value. Also fixes
  :ghissue:`3232`. Further, :ghissue:`3392` no longer validates claims provided that
  CouchDB does not require.
* :ghissue:`3160`, :ghissue:`3161`: The ``run_queue`` statistic now returns valid
  information even when using Erlang BEAM dirty CPU and IO queues.
* :ghissue:`3162`: Makefiles updated to include local configs & clean configs when
  running ``make devclean``.
* :ghissue:`3195`: The ``max_document_size`` parameter now has a clearer explanation in
  ``default.ini``.
* :ghissue:`3207`, :ghissue:`2536`: Improve the ``INSTALL.Unix.md`` file.
* :ghissue:`3212`: Base and extra headers are properly combined when making replicator
  requests that contain duplicate headers.
* :ghissue:`3201`: When using a POST with request body to pass parameters to a view-like
  request, the boolean parameters are accepting only JSON strings, but not booleans.
  Now, CouchDB accepts ``true`` and ``false`` for the ``stable`` parameter, in addition
  to ``"true"`` and ``"false"``.
  comment in
* :ghissue:`1988`: Attachment operations ``PUT /db/doc`` and ``POST /db`` now perform
  consistent attachment name validation.
* :ghissue:`3249`: Documents with lots of conflicts no longer blow up couchjs if the
  user calls ``_changes`` with a JS filter and with ``style=all_docs``.
* :ghissue:`3144`: Respawning compaction jobs to catch up with intervening changes are
  now handled correctly by the smoosh monitor.
* :ghissue:`3252`: CouchDB now exports the ``couch_util:json_decode/2`` function to
  support maps instead of the default data structure.
* :ghissue:`3255`, :ghissue:`2558`: View files that have incorrect ``db_headers``
  now reset the index forcing a rebuild.
* :ghissue:`3271`: Attachments that are stored uncompressed but later replicated to
  nodes that compress the attachment no longer fail an internal md5 check that would
  break eventual consistency between nodes.
* :ghissue:`3277`: ``req_body`` requests that have ``req_body`` set already now
  properly return the field without parsing.
* :ghissue:`3279`: Some default headers were missing from some responses in replication,
  including ``X-CouchDB-Body-Time`` and ``X-Couch-Request-ID``.
* :ghissue:`3329`, :ghissue:`2962`: CouchDB no longer returns broken couchjs processes
  to the internal viewserver process pool.
* :ghissue:`3340`, :ghissue:`1943`: ``PUTs`` of ``multipart/related`` attachments now
  support a ``Transfer-Encoding`` value of ``chunked``. Hooray!
* :ghissue:`2858`, :ghissue:`3359`: The cluster setup wizard no longer fails when a
  request to ``/`` is not made before a request to ``finish_cluster``.
* :ghissue:`3368`: Changing the ``max_dbs_open`` configuration setting correctly
  ensures that each new ``couch_server_X`` property receives ``1/num_servers()`` of it.
* :ghissue:`3373`: Requests to ``{db}/_changes`` with a custom filter no longer result
  in a fabric request timeout if the request body is not available to additional cluster
  nodes, resulting in a more descriptive exit message and proper JSON object validation
  in the payload.
* :ghissue:`3409`: The internal ``chttpd_external:json_req_obj/2`` function now reads
  the cached ``peer`` before falling back to a socket read operation.
* :ghissue:`3335`, :ghissue:`3617`, :ghissue:`3708`: The ``COUCHDB_FAUXTON_DOCROOT``
  environment variable is now introduced to allow its explicit overriding at startup.
* :ghissue:`3471`: http clients should no longer receive stacktraces unexpectedly.
* :ghissue:`3491`: libicu tests no longer fail on older OS releases such as CentOS 6
  and 7.
* :ghissue:`3541`: Usernames and passwords can now contain `@` and not break the
  CouchDB replicator.
* :ghissue:`3545`: The ``dreyfus_index_manager`` process now supports offheap message
  queues.
* :ghissue:`3551`: The replication worker pool now properly cleans up worker processes
  as they are done via the ``worker_trap_exits = false`` setting.
* :ghissue:`3633`, :ghissue:`3631`: All code paths for creating databases now fully
  respect db creation options, including partitioning options.
* :ghissue:`3424`, :ghissue:`3362`: When using ``latest=true`` and an old revision with
  conflicting children as rev is specified, CouchDB no longer returns an ``"error":
  "case_clause"`` response.
* :ghissue:`3673`: Non-existent attachments now return a ``404`` when the attachment
  is missing.
* :ghissue:`3698`: The ``dev/run`` development script now allows clusters where ``n >
  5``.
* :ghissue:`3700`: The ``maybe_close`` message is now sent to the correct internal
  process.
* :ghissue:`3183`: The smoosh operator guide now recommends to use the ``rpc:multicall``
  function.
* :ghissue:`3712`: Including a payload within a ``DELETE`` operation no longer hangs
  the next request made to the same mochiweb acceptor.
* :ghissue:`3715`: For clusters with databases where ``n > [cluster] n``, attachments
  chunks are longer dropped on quorum writes.
* :ghissue:`3507`: If a file is truncated underneath CouchDB, CouchDB will now log
  the filename if it finds this situation with a ``file_truncate_error``.
* :ghissue:`3739`: Shards with large purge sequences no longer fail to split in a
  shard splitting job.
* :ghissue:`3754`: Always return views meta info when ``limit=0`` and
  ``sorted=true``.
* :ghissue:`3757`: Properly sort ``descending=true`` view results with a ``keys``
  list.
* :ghissue:`3763`: Stabilize view row sorting order when they are merged by the
  coordinator.

Other
-----

* Donuts for everyone! Er, not really - thank you for reading the 3.2 release notes.