ceph/PendingReleaseNotes

14.2.1
------

* The default value for `mon_crush_min_required_version` has been
  changed from `firefly` to `hammer`, which means the cluster will
  issue a health warning if your CRUSH tunables are older than hammer.
  There is generally a small (but non-zero) amount of data that will
  move around by making the switch to hammer tunables; for more information,
  see :ref:`crush-map-tunables`.

  If possible, we recommend that you set the oldest allowed client to `hammer`
  or later.  You can tell what the current oldest allowed client is with::

    ceph osd dump | min_compat_client

  If the current value is older than hammer, you can tell whether it
  is safe to make this change by verifying that there are no clients
  older than hammer current connected to the cluster with::

    ceph features

  The newer `straw2` CRUSH bucket type was introduced in hammer, and
  ensuring that all clients are hammer or newer allows new features
  only supported for `straw2` buckets to be used, including the
  `crush-compat` mode for the :ref:`balancer`.


14.2.5
------

* Ceph will now issue a health warning if a RADOS pool as a ``pg_num``
  value that is not a power of two.  This can be fixed by adjusting
  the pool to a nearby power of two::

    ceph osd pool set <pool-name> pg_num <new-pg-num>

  Alternatively, the warning can be silenced with::

    ceph config set global mon_warn_on_pool_pg_num_not_power_of_two false


>=15.0.0
--------

* The RGW "num_rados_handles" has been removed.
  * If you were using a value of "num_rados_handles" greater than 1
    multiply your current "objecter_inflight_ops" and 
    "objecter_inflight_op_bytes" paramaeters by the old
    "num_rados_handles" to get the same throttle behavior.

* Ceph now packages python bindings for python3.6 instead of
  python3.4, because EPEL7 recently switched from python3.4 to
  python3.6 as the native python3. see the `announcement <https://lists.fedoraproject.org/archives/list/epel-announce@lists.fedoraproject.org/message/EGUMKAIMPK2UD5VSHXM53BH2MBDGDWMO/>_`
  for more details on the background of this change.

* librbd now uses a write-around cache policy be default,
  replacing the previous write-back cache policy default.
  This cache policy allows librbd to immediately complete
  write IOs while they are still in-flight to the OSDs.
  Subsequent flush requests will ensure all in-flight
  write IOs are completed prior to completing. The
  librbd cache policy can be controlled via a new
  "rbd_cache_policy" configuration option.

* librbd now includes a simple IO scheduler which attempts to
  batch together multiple IOs against the same backing RBD
  data block object. The librbd IO scheduler policy can be
  controlled via a new "rbd_io_scheduler" configuration
  option.

* RGW: radosgw-admin introduces two subcommands that allow the
  managing of expire-stale objects that might be left behind after a
  bucket reshard in earlier versions of RGW. One subcommand lists such
  objects and the other deletes them. Read the troubleshooting section
  of the dynamic resharding docs for details.

* RGW: Bucket naming restrictions have changed and likely to cause
  InvalidBucketName errors. We recommend to set ``rgw_relaxed_s3_bucket_names``
  option to true as a workaround.

* In the Zabbix Mgr Module there was a typo in the key being send
  to Zabbix for PGs in backfill_wait state. The key that was sent
  was 'wait_backfill' and the correct name is 'backfill_wait'.
  Update your Zabbix template accordingly so that it accepts the
  new key being send to Zabbix.

* zabbix plugin for ceph manager now includes osd and pool
  discovery. Update of zabbix_template.xml is needed
  to receive per-pool (read/write throughput, diskspace usage)
  and per-osd (latency, status, pgs) statistics

* The format of all date + time stamps has been modified to fully
  conform to ISO 8601.  The old format (``YYYY-MM-DD
  HH:MM:SS.ssssss``) excluded the ``T`` separator between the date and
  time and was rendered using the local time zone without any explicit
  indication.  The new format includes the separator as well as a
  ``+nnnn`` or ``-nnnn`` suffix to indicate the time zone, or a ``Z``
  suffix if the time is UTC.  For example,
  ``2019-04-26T18:40:06.225953+0100``.

  Any code or scripts that was previously parsing date and/or time
  values from the JSON or XML structure CLI output should be checked
  to ensure it can handle ISO 8601 conformant values.  Any code
  parsing date or time values from the unstructured human-readable
  output should be modified to parse the structured output instead, as
  the human-readable output may change without notice.

* The ``bluestore_no_per_pool_stats_tolerance`` config option has been
  replaced with ``bluestore_fsck_error_on_no_per_pool_stats``
  (default: false).  The overall default behavior has not changed:
  fsck will warn but not fail on legacy stores, and repair will
  convert to per-pool stats.

* The ``osd_recovery_max_active`` option now has
  ``osd_recovery_max_active_hdd`` and ``osd_recovery_max_active_ssd``
  variants, each with different default values for HDD and SSD-backed
  OSDs, respectively.  By default ``osd_recovery_max_active`` now
  defaults to zero, which means that the OSD will conditionally use
  the HDD or SSD option values.  Administrators who have customized
  this value may want to consider whether they have set this to a
  value similar to the new defaults (3 for HDDs and 10 for SSDs) and,
  if so, remove the option from their configuration entirely.

* monitors now have a `ceph osd info` command that will provide information
  on all osds, or provided osds, thus simplifying the process of having to
  parse `osd dump` for the same information.

* The structured output of ``ceph status`` or ``ceph -s`` is now more
  concise, particularly the `mgrmap` and `monmap` sections, and the
  structure of the `osdmap` section has been cleaned up.

* A health warning is now generated if the average osd heartbeat ping
  time exceeds a configurable threshold for any of the intervals
  computed.  The OSD computes 1 minute, 5 minute and 15 minute
  intervals with average, minimum and maximum values.  New configuration
  option ``mon_warn_on_slow_ping_ratio`` specifies a percentage of
  ``osd_heartbeat_grace`` to determine the threshold.  A value of zero
  disables the warning.  New configuration option
 ``mon_warn_on_slow_ping_time`` specified in milliseconds over-rides the
  computed value, causes a warning
  when OSD heartbeat pings take longer than the specified amount.
  New admin command ``ceph daemon mgr.# dump_osd_network [threshold]`` command will
  list all connections with a ping time longer than the specified threshold or
  value determined by the config options, for the average for any of the 3 intervals.
  New admin command ``ceph daemon osd.# dump_osd_network [threshold]`` will
  do the same but only including heartbeats initiated by the specified OSD.

* Inline data support for CephFS has been deprecated. When setting the flag,
  users will see a warning to that effect, and enabling it now requires the
  ``--yes-i-really-really-mean-it`` flag. If the MDS is started on a
  filesystem that has it enabled, a health warning is generated. Support for
  this feature will be removed in a future release.

* ``ceph {set,unset} full`` is not supported anymore. We have been using
  ``full`` and ``nearfull`` flags in OSD map for tracking the fullness status
  of a cluster back since the Hammer release, if the OSD map is marked ``full``
  all write operations will be blocked until this flag is removed. In the
  Infernalis release and Linux kernel 4.7 client, we introduced the per-pool
  full/nearfull flags to track the status for a finer-grained control, so the
  clients will hold the write operations if either the cluster-wide ``full``
  flag or the per-pool ``full`` flag is set. This was a compromise, as we
  needed to support the cluster with and without per-pool ``full`` flags
  support. But this practically defeated the purpose of introducing the
  per-pool flags. So, in the Mimic release, the new flags finally took the
  place of their cluster-wide counterparts, as the monitor started removing
  these two flags from OSD map. So the clients of Infernalis and up can benefit
  from this change, as they won't be blocked by the full pools which they are
  not writing to. In this release, ``ceph {set,unset} full`` is now considered
  as an invalid command. And the clients will continue honoring both the
  cluster-wide and per-pool flags to be backward comaptible with pre-infernalis
  clusters.

* Following invalid settings now are not tolerated anymore
  for the command `ceph osd erasure-code-profile set xxx`.
  * invalid `m` for "reed_sol_r6_op" erasure technique
  * invalid `m` and invalid `w` for "liber8tion" erasure technique

* New OSD daemon command dump_recovery_reservations which reveals the
  recovery locks held (in_progress) and waiting in priority queues.

* New OSD daemon command dump_scrub_reservations which reveals the
  scrub reservations that are held for local (primary) and remote (replica) PGs.

* Ceph will now issue a health warning if a RADOS pool as a ``pg_num``
  value that is not a power of two.  This can be fixed by adjusting
  the pool to a nearby power of two::

    ceph osd pool set <pool-name> pg_num <new-pg-num>

  Alternatively, the warning can be silenced with::

    ceph config set global mon_warn_on_pool_pg_num_not_power_of_two false

* The ``pg_autoscale_mode`` is now set to ``on`` by default for newly
  created pools, which means that Ceph will automatically manage the
  number of PGs.  To change this behavior, or to learn more about PG
  autoscaling, see :ref:`pg-autoscaler`.  Note that existing pools in
  upgraded clusters will still be set to ``warn`` by default.

* The ``upmap_max_iterations`` config option of mgr/balancer has been
  renamed to ``upmap_max_optimizations`` to better match its behaviour.