Add Queens release note

Change-Id: Ib28982138d7c2cef98a667307a6a2a9fd64ab3cd
This commit is contained in:
Brian Rosmaita 2018-01-18 00:56:16 -05:00
parent 73f0fca99c
commit 38d9bcb2aa
1 changed files with 52 additions and 0 deletions

View File

@ -0,0 +1,52 @@
---
prelude: >
This was a quiet development cycle for the ``glance_store`` library.
One new feature was added to the Swift store driver. Several bugs
were fixed and some code changes were committed to increase stability.
features:
- |
A `BufferedReader`_ has been added to the Swift store driver in
order to enable better recovery from errors during uploads of large
image files. Because this reader buffers image data, it could
cause Glance to use a much larger amount of disk space, and so the
Buffered Reader is *not* enabled by default.
To use the new reader with the Swift store, you must do the following:
* Set the ``glance_store`` configuration option ``swift_buffer_on_upload``
to ``True``
* Set the ``glance_store`` configuration option ``swift_upload_buffer_dir``
to a string value representing an absolute directory path. This
directory will be used to hold the buffered data.
The Buffered Reader works by taking advantage of the way Swift stores
large objects by segmenting them into discrete chunks. Thus, the amount
of disk space a Glance API node will require for buffering is a function
of the ``swift_store_large_object_chunk_size`` setting and the number of
worker threads (configured in **glance-api.conf** as the value of
``workers``). Disk utilization will cap at the following value
swift_store_large_object_chunk_size * workers * 1000
Be aware that depending upon how the file system is configured, the disk
space used for buffering may decrease the actual disk space available for
the Glance image cache, which may affect overall performance.
For more information, see the `Buffered Reader for Swift Driver`_ spec.
.. _BufferedReader: http://git.openstack.org/cgit/openstack/glance_store/commit/?id=2e0024c85ca2ddf380014e44213be4fb876f680e
.. _Buffered Reader for Swift Driver: http://specs.openstack.org/openstack/glance-specs/specs/mitaka/approved/buffered-reader-for-swift-driver.html
fixes:
- |
* Bug 1738331_: Fix BufferedReader writing zero size chunks
* Bug 1733502_: Use cached auth_ref instead of getting a new one each time
.. _1738331: https://code.launchpad.net/bugs/1738331
.. _1733502: https://code.launchpad.net/bugs/1733502
upgrade:
- |
Two new configuration options, ``swift_buffer_on_upload`` and
``swift_upload_buffer_dir`` have been introduced. These apply only to
users of the Swift store and their use is optional. See the New Features
section for more information.