src/docs/src/whatsnew/2.0.rst
.. 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 .. .. Unless required by applicable law or agreed to in writing, software .. 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/2.0.x:
.. contents:: :depth: 1 :local:
.. _release/2.0.0:
Native clustering is now supported. Rather than use CouchDB replication
between multiple, distinct CouchDB servers, configure a cluster of CouchDB
nodes. These nodes will use an optimized Erlang-driven 'internal replication'
to ensure data durability and accessibility. Combine a clustered CouchDB with
a load balancer (such as haproxy) to scale CouchDB out horizontally. More
details of the clustering feature are available in the :ref:cluster.
Futon replaced by brand-new, completely re-engineered Fauxton interface.
URL remains the same.
The new Mango Query Server provides a simple JSON-based way to perform CouchDB
queries without JavaScript or MapReduce. Mango Queries have a similar indexing
speed advantage over JavaScript Queries than the Erlang Queries have (2x-10x
faster indexing depending on doc size and system configuration). We recommend
all new apps start using Mango as a default. Further details are available
in the :ref:_find, _index and _explain API <api/db/_find>.
Mango :ref:selectors <changes/filter/selector> can be used in _changes
feeds instead of JavaScript MapReduce filters. Mango has been tested to be
up to an order of magnitude (10x) faster than JavaScript in this application.
:ref:Rewrite rules <api/ddoc/rewrite> for URLs can be performed using
JavaScript functions.
:ref:Multiple queries <api/ddoc/view/multiple_queries> can be made of a
view with a single HTTP request.
Views can be queried with sorting turned off ( sorted=false) for a
performance boost.
The global changes feed has been enhanced. It is now resumable and persistent.
New endpoints added (documentation forthcoming):
api/server/membership shows all nodes in a cluster/_bulk_get speeds up the replication protocol over low-latency
connections/_node/ api to access individual nodes' configuration and compaction
features/_cluster_setup api to set up a cluster from scratch./_up api to signal health of a node to a load-balancer/db/_local_docs and /db/_design_docs (similar to /db/_all_docs)The /_log endpoint was removed.
"Backend" interface on port 5986 used for specific cluster admin tasks. Of
interest are the _nodes and _dbs databases visible only through this
interface.
Support added for Erlang/OTP 17.x, 18.x and 19
New streamlined build system written for Unix-like systems and Microsoft Windows
:ref:Configuration <api/config> has moved from /_config to
/_node/{node-name}/_config
instance_start_time now always reports "0".
.. _release/2.0.x/upgrade:
api/db/changes feed are no longer
integers. They can be any JSON value. Applications should treat them as opaque
values and return them to CouchDB as-is.replicator/db config option has been removed.
Instead _replicator and any database names ending
with the /_replicator suffix will be recognized as
replicator databases by the system.201 and a 202 when storing a document.all_or_nothing is no longer supported by the :ref:bulk_docs <api/db/bulk_docs> APIshow, an immediate GET to
that same show function may still return results from the previous
definition. This is due to design document caching, which may take a few
seconds to fully evict, or longer (up to ~30s) for a clustered installation... _release/2.0.x/knownissues:
All known issues_ filed against the 2.0 release are contained within the
official CouchDB JIRA instance or CouchDB GitHub Issues.
The following are some highlights of known issues for which fixes did not land in time for the 2.0.0 release:
:issue:2980: The replicator (whether invoked via _replicate or a
document stored in the _replicator database) understands two kinds of
source and target:
#. A URL (e.g., https://foo:[email protected]/db1), called a "remote" source or
target
#. A database name (e.g., db1), called a "local" source or target.
Whenever the latter type is used, this refers to a local unclustered database, not a clustered one.
In a future release we hope to support "local" source or target specs to clustered databases. For now, we recommend always using the URL format for both source and target specifications.
:issue:3034: CouchDB will occasionally return 500 errors when multiple
clients attempt to PUT or DELETE the same database concurrently.
:issue:3119: Adding nodes to a cluster fails if the Erlang node name
is not couchdb (of the form couchdb@hostname.)
:issue:3050: Occasionally the dev/run script used for development
purposes to start a local 3-node cluster will fail to start one or more
nodes.
:issue:2817: The compaction daemon will only compact views for shards
that contain the design document.
:issue:2804: The fast_view optimization is not enabled on the clustered
interface.
:ghissue:656: The OAuth 1.0 support is broken and deprecated. It will be
removed in a future version of CouchDB.
.. _known issues: https://s.apache.org/couchdb-2.0-known-issues .. _CouchDB JIRA instance: https://issues.apache.org/jira/browse/COUCHDB .. _CouchDB GitHub Issues: https://github.com/apache/couchdb/issues
.. _release/2.0.x/breakingchanges:
The following changes in 2.0 represent a significant deviation from CouchDB 1.x and may alter behaviour of systems designed to work with older versions of CouchDB:
620: POST /dbname no longer returns an ETag response header,
in compliance with RFC 7231, Section 7.2.