Release Notes
===============
+v0.94.1 Hammer
+==============
+
+This bug fix release fixes a few critical issues with CRUSH. The most
+important addresses a bug in feature bit enforcement that may prevent
+pre-hammer clients from communicating with the cluster during an
+upgrade. This only manifests in some cases (for example, when the
+'rack' type is in use in the CRUSH map, and possibly other cases), but for
+safety we strongly recommend that all users use 0.94.1 instead of 0.94 when
+upgrading.
+
+There is also a fix in the new straw2 buckets when OSD weights are 0.
+
+We recommend that all v0.94 users upgrade.
+
+Notable changes
+---------------
+
+* crush: fix divide-by-0 in straw2 (#11357 Sage Weil)
+* crush: fix has_v4_buckets (#11364 Sage Weil)
+* osd: fix negative degraded objects during backfilling (#7737 Guang Yang)
+
+For more detailed information, see :download:`the complete changelog <changelog/v0.94.1.txt>`.
+
+
+v0.94 Hammer
+============
+
+This major release is expected to form the basis of the next long-term
+stable series. It is intended to supersede v0.80.x Firefly.
+
+Highlights since Giant include:
+
+* *RADOS Performance*: a range of improvements have been made in the
+ OSD and client-side librados code that improve the throughput on
+ flash backends and improve parallelism and scaling on fast machines.
+* *Simplified RGW deployment*: the ceph-deploy tool now has a new
+ 'ceph-deploy rgw create HOST' command that quickly deploys a
+ instance of the S3/Swift gateway using the embedded Civetweb server.
+ This is vastly simpler than the previous Apache-based deployment.
+ There are a few rough edges (e.g., around SSL support) but we
+ encourage users to try `the new method`_.
+* *RGW object versioning*: RGW now supports the S3 object versioning
+ API, which preserves old version of objects instead of overwriting
+ them.
+* *RGW bucket sharding*: RGW can now shard the bucket index for large
+ buckets across, improving performance for very large buckets.
+* *RBD object maps*: RBD now has an object map function that tracks
+ which parts of the image are allocating, improving performance for
+ clones and for commands like export and delete.
+* *RBD mandatory locking*: RBD has a new mandatory locking framework
+ (still disabled by default) that adds additional safeguards to
+ prevent multiple clients from using the same image at the same time.
+* *RBD copy-on-read*: RBD now supports copy-on-read for image clones,
+ improving performance for some workloads.
+* *CephFS snapshot improvements*: Many many bugs have been fixed with
+ CephFS snapshots. Although they are still disabled by default,
+ stability has improved significantly.
+* *CephFS Recovery tools*: We have built some journal recovery and
+ diagnostic tools. Stability and performance of single-MDS systems is
+ vastly improved in Giant, and more improvements have been made now
+ in Hammer. Although we still recommend caution when storing
+ important data in CephFS, we do encourage testing for non-critical
+ workloads so that we can better guage the feature, usability,
+ performance, and stability gaps.
+* *CRUSH improvements*: We have added a new straw2 bucket algorithm
+ that reduces the amount of data migration required when changes are
+ made to the cluster.
+* *Shingled erasure codes (SHEC)*: The OSDs now have experimental
+ support for shingled erasure codes, which allow a small amount of
+ additional storage to be traded for improved recovery performance.
+* *RADOS cache tiering*: A series of changes have been made in the
+ cache tiering code that improve performance and reduce latency.
+* *RDMA support*: There is now experimental support the RDMA via the
+ Accelio (libxio) library.
+* *New administrator commands*: The 'ceph osd df' command shows
+ pertinent details on OSD disk utilizations. The 'ceph pg ls ...'
+ command makes it much simpler to query PG states while diagnosing
+ cluster issues.
+
+.. _the new method: ../start/quick-ceph-deploy/#add-an-rgw-instance
+
+Other highlights since Firefly include:
+
+* *CephFS*: we have fixed a raft of bugs in CephFS and built some
+ basic journal recovery and diagnostic tools. Stability and
+ performance of single-MDS systems is vastly improved in Giant.
+ Although we do not yet recommend CephFS for production deployments,
+ we do encourage testing for non-critical workloads so that we can
+ better guage the feature, usability, performance, and stability
+ gaps.
+* *Local Recovery Codes*: the OSDs now support an erasure-coding scheme
+ that stores some additional data blocks to reduce the IO required to
+ recover from single OSD failures.
+* *Degraded vs misplaced*: the Ceph health reports from 'ceph -s' and
+ related commands now make a distinction between data that is
+ degraded (there are fewer than the desired number of copies) and
+ data that is misplaced (stored in the wrong location in the
+ cluster). The distinction is important because the latter does not
+ compromise data safety.
+* *Tiering improvements*: we have made several improvements to the
+ cache tiering implementation that improve performance. Most
+ notably, objects are not promoted into the cache tier by a single
+ read; they must be found to be sufficiently hot before that happens.
+* *Monitor performance*: the monitors now perform writes to the local
+ data store asynchronously, improving overall responsiveness.
+* *Recovery tools*: the ceph-objectstore-tool is greatly expanded to
+ allow manipulation of an individual OSDs data store for debugging
+ and repair purposes. This is most heavily used by our QA
+ infrastructure to exercise recovery code.
+
+I would like to take this opportunity to call out the amazing growth
+in contributors to Ceph beyond the core development team from Inktank.
+Hammer features major new features and improvements from Intel, Fujitsu,
+UnitedStack, Yahoo, UbuntuKylin, CohortFS, Mellanox, CERN, Deutsche
+Telekom, Mirantis, and SanDisk.
+
+Dedication
+----------
+
+This release is dedicated in memoriam to Sandon Van Ness, aka
+Houkouonchi, who unexpectedly passed away a few weeks ago. Sandon was
+responsible for maintaining the large and complex Sepia lab that
+houses the Ceph project's build and test infrastructure. His efforts
+have made an important impact on our ability to reliably test Ceph
+with a relatively small group of people. He was a valued member of
+the team and we will miss him. H is also for Houkouonchi.
+
+Upgrading
+---------
+
+* If your existing cluster is running a version older than v0.80.x
+ Firefly, please first upgrade to the latest Firefly release before
+ moving on to Giant. We have not tested upgrades directly from
+ Emperor, Dumpling, or older releases.
+
+ We *have* tested:
+
+ * Firefly to Hammer
+ * Giant to Hammer
+ * Dumpling to Firefly to Hammer
+
+* Please upgrade daemons in the following order:
+
+ #. Monitors
+ #. OSDs
+ #. MDSs and/or radosgw
+
+ Note that the relative ordering of OSDs and monitors should not matter, but
+ we primarily tested upgrading monitors first.
+
+* The ceph-osd daemons will perform a disk-format upgrade improve the
+ PG metadata layout and to repair a minor bug in the on-disk format.
+ It may take a minute or two for this to complete, depending on how
+ many objects are stored on the node; do not be alarmed if they do
+ not marked "up" by the cluster immediately after starting.
+
+* If upgrading from v0.93, set
+ osd enable degraded writes = false
+
+ on all osds prior to upgrading. The degraded writes feature has
+ been reverted due to 11155.
+
+* The LTTNG tracing in librbd and librados is disabled in the release packages
+ until we find a way to avoid violating distro security policies when linking
+ libust.
+
v0.92
=====
projects / ceph.git / commitdiff