Kinto

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**Operational concerns**

- *The schema for the Postgres storage backend has changed.* This
changes some more ID columns to use the "C" collation, which fixes a
bug where the ``bump_timestamps`` trigger was very slow.

------------------

**Internal changes**

- Update the Docker compose configuration to use memcache for the cache backend (1405)
- Refactor the way postgresql.storage.create_from_settings ignores settings (1410)

**Operational concerns**

- *The schema for the Postgres storage backend has changed.* This
changes some ID columns to use the "C" collation, which will make
``delete_all`` queries faster. (See
e.g. https://www.postgresql.org/docs/9.6/static/indexes-opclass.html,
which says "If you do use the C locale, you do not need the
xxx_pattern_ops operator classes, because an index with the default
operator class is usable for pattern-matching queries in the C
locale.") This may change the default sort order and grouping of
record IDs.

**New features**

- New setting ``kinto.backoff_percentage`` to only set the backoff header a portion of the time.
- ``make tdd`` allows development in a TDD style by rerunning tests every time a file is changed.

**Bug fixes**

- Optimize the Postgres collection_timestamp method by one query. It
now only makes two queries instead of three.
- Update other dependencies: newrelic to 2.98.0.81 (1409), setuptools
to 38.4.0 (1411, 1429, 1438, 1440), pytest to 3.3.2 (1412,
1437), raven to 6.4.0 (1421), werkzeug to 0.14.1 (1418, 1434),
python-memcached to 1.59 (1423), zest.releaser to 6.13.3 (1427),
bravado_core to 4.11.2 (1426, 1441), statsd to 3.2.2 (1422),
jsonpatch to 1.21 (1432), sqlalchemy to 1.2.0 (1430), sphinx to
1.6.6 (1442).

------------------

**Breaking changes**

- Storage backends no longer support the ``ignore_conflict``
argument (1401). Instead of using this argument, consider catching the
``UnicityError`` and handling it. ``ignore_conflict`` was only ever
used in one place, in the ``default_bucket`` plugin, and was
eventually backed out in favor of catching and handling a
``UnicityError``.

**Bug fixes**

- Fix a TOCTOU bug in the Postgres storage backend where a transaction
doing a `create()` would fail because a row had been inserted after
the transaction had checked for it (1376).

------------------

**Operational concerns**

- *The schema for the Postgres ``storage`` backend has changed.* This
lets us prevent a race condition where deleting and creating a thing
at the same time can leave it in an inconsistent state (1386). You
will have to run the ``kinto migrate`` command in order to migrate
the schema.

**Bug fixes**

- Document how to create an account using the ``POST /accounts`` endpoint (1385).

**Internal changes**

- Update dependency on pytest to move to 3.3.0 (1403).
- Update other dependencies: setuptools to 38.2.1 (1380, 1381,
1392, 1395), jsonpatch to 1.20 (1393), zest.releaser to 6.13.2
(1397), paste-deploy to 0.4.2 (1384), webob to 1.7.4 (1383),
simplejson to 3.13.2 (1389, 1390).
- Undo workaround for broken kinto-http.js in the kinto-admin plugin
(1382).

------------------

**Bug fixes**

- Fix kinto-admin loading.

------------------

**Protocol**

- When a record is pushed with an older timestamp, the collection
timestamps is not bumped anymore. (1361)

**New features**

- A new custom logging formatter is available in ``kinto.core``. It fixes the issues of
`mozilla-cloud-services-logger <https://github.com/mozilla/mozilla-cloud-services-logger>`_.
Consider migrating your logging settings to :

::

[formatter_json]
class = kinto.core.JsonLogFormatter

**Bug fixes**

- Do not log empty context values (ref 1363)
- Fixed some attributes in logging of errors (ref 1363)
- Fixed logging of method/path of batch subrequests (ref 1363)
- Fix removing permissions with Json Merge (1322).


**Internal changes**

- Moved PostgreSQL helper function to Python code (ref 1358)