[ceph.git] / ceph / doc / rados / configuration / mon-osd-interaction.rst

=====================================
 Configuring Monitor/OSD Interaction
=====================================

.. index:: heartbeat

After you have completed your initial Ceph configuration, you may deploy and run
Ceph.  When you execute a command such as ``ceph health`` or ``ceph -s``,  the
:term:`Ceph Monitor` reports on the current state of the :term:`Ceph Storage
Cluster`. The Ceph Monitor knows about the Ceph Storage Cluster by requiring
reports from each :term:`Ceph OSD Daemon`, and by receiving reports from Ceph
OSD Daemons about the status of their neighboring Ceph OSD Daemons. If the Ceph
Monitor doesn't receive reports, or if it receives reports of changes in the
Ceph Storage Cluster, the Ceph Monitor updates the status of the :term:`Ceph
Cluster Map`.

Ceph provides reasonable default settings for Ceph Monitor/Ceph OSD Daemon
interaction. However, you may override the defaults. The following sections
describe how Ceph Monitors and Ceph OSD Daemons interact for the purposes of
monitoring the Ceph Storage Cluster.

.. index:: heartbeat interval

OSDs Check Heartbeats
=====================

Each Ceph OSD Daemon checks the heartbeat of other Ceph OSD Daemons every 6
seconds. You can change the heartbeat interval by adding an ``osd heartbeat
interval`` setting under the ``[osd]`` section of your Ceph configuration file,
or by setting the value at runtime. If a neighboring Ceph OSD Daemon doesn't
show a heartbeat within a 20 second grace period, the Ceph OSD Daemon may
consider the neighboring Ceph OSD Daemon ``down`` and report it back to a Ceph
Monitor, which will update the Ceph Cluster Map. You may change this grace
period by adding an ``osd heartbeat grace`` setting under the ``[mon]``
and ``[osd]`` or ``[global]`` section of your Ceph configuration file,
or by setting the value at runtime.


.. ditaa:: +---------+          +---------+
           |  OSD 1  |          |  OSD 2  |
           +---------+          +---------+
                |                    |
                |----+ Heartbeat     |
                |    | Interval      |
                |<---+ Exceeded      |
                |                    |
                |       Check        |
                |     Heartbeat      |
                |------------------->|
                |                    |
                |<-------------------|
                |   Heart Beating    |
                |                    |
                |----+ Heartbeat     |
                |    | Interval      |
                |<---+ Exceeded      |
                |                    |
                |       Check        |
                |     Heartbeat      |
                |------------------->|
                |                    |
                |----+ Grace         |
                |    | Period        |
                |<---+ Exceeded      |
                |                    |
                |----+ Mark          |
                |    | OSD 2         |
                |<---+ Down          |


.. index:: OSD down report

OSDs Report Down OSDs
=====================

By default, two Ceph OSD Daemons from different hosts must report to the Ceph
Monitors that another Ceph OSD Daemon is ``down`` before the Ceph Monitors
acknowledge that the reported Ceph OSD Daemon is ``down``. But there is chance
that all the OSDs reporting the failure are hosted in a rack with a bad switch
which has trouble connecting to another OSD. To avoid this sort of false alarm,
we consider the peers reporting a failure a proxy for a potential "subcluster"
over the overall cluster that is similarly laggy. This is clearly not true in
all cases, but will sometimes help us localize the grace correction to a subset
of the system that is unhappy. ``mon osd reporter subtree level`` is used to
group the peers into the "subcluster" by their common ancestor type in CRUSH
map. By default, only two reports from different subtree are required to report
another Ceph OSD Daemon ``down``. You can change the number of reporters from
unique subtrees and the common ancestor type required to report a Ceph OSD
Daemon ``down`` to a Ceph Monitor by adding an ``mon osd min down reporters``
and ``mon osd reporter subtree level`` settings  under the ``[mon]`` section of
your Ceph configuration file, or by setting the value at runtime.


.. ditaa:: +---------+     +---------+      +---------+
           |  OSD 1  |     |  OSD 2  |      | Monitor |
           +---------+     +---------+      +---------+
                |               |                |
                | OSD 3 Is Down |                |
                |---------------+--------------->|
                |               |                |
                |               |                |
                |               | OSD 3 Is Down  |
                |               |--------------->|
                |               |                |
                |               |                |
                |               |                |---------+ Mark
                |               |                |         | OSD 3
                |               |                |<--------+ Down


.. index:: peering failure

OSDs Report Peering Failure
===========================

If a Ceph OSD Daemon cannot peer with any of the Ceph OSD Daemons defined in its
Ceph configuration file (or the cluster map), it will ping a Ceph Monitor for
the most recent copy of the cluster map every 30 seconds. You can change the
Ceph Monitor heartbeat interval by adding an ``osd mon heartbeat interval``
setting under the ``[osd]`` section of your Ceph configuration file, or by
setting the value at runtime.

.. ditaa:: +---------+     +---------+     +-------+     +---------+
           |  OSD 1  |     |  OSD 2  |     | OSD 3 |     | Monitor |
           +---------+     +---------+     +-------+     +---------+
                |               |              |              |
                |  Request To   |              |              |
                |     Peer      |              |              |
                |-------------->|              |              |
                |<--------------|              |              |
                |    Peering                   |              |
                |                              |              |
                |  Request To                  |              |
                |     Peer                     |              |
                |----------------------------->|              |
                |                                             |
                |----+ OSD Monitor                            |
                |    | Heartbeat                              |
                |<---+ Interval Exceeded                      |
                |                                             |
                |         Failed to Peer with OSD 3           |
                |-------------------------------------------->|
                |<--------------------------------------------|
                |          Receive New Cluster Map            |


.. index:: OSD status

OSDs Report Their Status
========================

If an Ceph OSD Daemon doesn't report to a Ceph Monitor, the Ceph Monitor will
consider the Ceph OSD Daemon ``down`` after the  ``mon osd report timeout``
elapses. A Ceph OSD Daemon sends a report to a Ceph Monitor when a reportable
event such as a failure, a change in placement group stats, a change in
``up_thru`` or when it boots within 5 seconds. You can change the Ceph OSD
Daemon minimum report interval by adding an ``osd mon report interval min``
setting under the ``[osd]`` section of your Ceph configuration file, or by
setting the value at runtime. A Ceph OSD Daemon sends a report to a Ceph
Monitor every 120 seconds irrespective of whether any notable changes occur.
You can change the Ceph Monitor report interval by adding an ``osd mon report
interval max`` setting under the ``[osd]`` section of your Ceph configuration
file, or by setting the value at runtime.


.. ditaa:: +---------+          +---------+
           |  OSD 1  |          | Monitor |
           +---------+          +---------+
                |                    |
                |----+ Report Min    |
                |    | Interval      |
                |<---+ Exceeded      |
                |                    |
                |----+ Reportable    |
                |    | Event         |
                |<---+ Occurs        |
                |                    |
                |     Report To      |
                |      Monitor       |
                |------------------->|
                |                    |
                |----+ Report Max    |
                |    | Interval      |
                |<---+ Exceeded      |
                |                    |
                |     Report To      |
                |      Monitor       |
                |------------------->|
                |                    |
                |----+ Monitor       |
                |    | Fails         |
                |<---+               |
                                     +----+ Monitor OSD
                                     |    | Report Timeout
                                     |<---+ Exceeded
                                     |
                                     +----+ Mark
                                     |    | OSD 1
                                     |<---+ Down


Configuration Settings
======================

When modifying heartbeat settings, you should include them in the ``[global]``
section of your configuration file.

.. index:: monitor heartbeat

Monitor Settings
----------------

``mon osd min up ratio``

:Description: The minimum ratio of ``up`` Ceph OSD Daemons before Ceph will
              mark Ceph OSD Daemons ``down``.

:Type: Double
:Default: ``.3``


``mon osd min in ratio``

:Description: The minimum ratio of ``in`` Ceph OSD Daemons before Ceph will
              mark Ceph OSD Daemons ``out``.

:Type: Double
:Default: ``.75``


``mon osd laggy halflife``

:Description: The number of seconds laggy estimates will decay.
:Type: Integer
:Default: ``60*60``


``mon osd laggy weight``

:Description: The weight for new samples in laggy estimation decay.
:Type: Double
:Default: ``0.3``


``mon osd laggy max interval``

:Description: Maximum value of ``laggy_interval`` in laggy estimations (in seconds).
              Monitor uses an adaptive approach to evaluate the ``laggy_interval`` of
              a certain OSD. This value will be used to calculate the grace time for
              that OSD.
:Type: Integer
:Default: 300

``mon osd adjust heartbeat grace``

:Description: If set to ``true``, Ceph will scale based on laggy estimations.
:Type: Boolean
:Default: ``true``


``mon osd adjust down out interval``

:Description: If set to ``true``, Ceph will scaled based on laggy estimations.
:Type: Boolean
:Default: ``true``


``mon osd auto mark in``

:Description: Ceph will mark any booting Ceph OSD Daemons as ``in``
              the Ceph Storage Cluster.

:Type: Boolean
:Default: ``false``


``mon osd auto mark auto out in``

:Description: Ceph will mark booting Ceph OSD Daemons auto marked ``out``
              of the Ceph Storage Cluster as ``in`` the cluster.

:Type: Boolean
:Default: ``true``


``mon osd auto mark new in``

:Description: Ceph will mark booting new Ceph OSD Daemons as ``in`` the
              Ceph Storage Cluster.

:Type: Boolean
:Default: ``true``


``mon osd down out interval``

:Description: The number of seconds Ceph waits before marking a Ceph OSD Daemon
              ``down`` and ``out`` if it doesn't respond.

:Type: 32-bit Integer
:Default: ``600``


``mon osd down out subtree limit``

:Description: The smallest :term:`CRUSH` unit type that Ceph will **not**
              automatically mark out. For instance, if set to ``host`` and if
              all OSDs of a host are down, Ceph will not automatically mark out
              these OSDs.

:Type: String
:Default: ``rack``


``mon osd report timeout``

:Description: The grace period in seconds before declaring
              unresponsive Ceph OSD Daemons ``down``.

:Type: 32-bit Integer
:Default: ``900``

``mon osd min down reporters``

:Description: The minimum number of Ceph OSD Daemons required to report a
              ``down`` Ceph OSD Daemon.

:Type: 32-bit Integer
:Default: ``2``


``mon osd reporter subtree level``

:Description: In which level of parent bucket the reporters are counted. The OSDs
              send failure reports to monitor if they find its peer is not responsive.
              And monitor mark the reported OSD out and then down after a grace period.
:Type: String
:Default: ``host``


.. index:: OSD hearbeat

OSD Settings
------------

``osd heartbeat address``

:Description: An Ceph OSD Daemon's network address for heartbeats.
:Type: Address
:Default: The host address.


``osd heartbeat interval``

:Description: How often an Ceph OSD Daemon pings its peers (in seconds).
:Type: 32-bit Integer
:Default: ``6``


``osd heartbeat grace``

:Description: The elapsed time when a Ceph OSD Daemon hasn't shown a heartbeat
              that the Ceph Storage Cluster considers it ``down``.
              This setting has to be set in both the [mon] and [osd] or [global]
              section so that it is read by both the MON and OSD daemons.
:Type: 32-bit Integer
:Default: ``20``


``osd mon heartbeat interval``

:Description: How often the Ceph OSD Daemon pings a Ceph Monitor if it has no
              Ceph OSD Daemon peers.

:Type: 32-bit Integer
:Default: ``30``


``osd mon report interval max``

:Description: The maximum time in seconds that a Ceph OSD Daemon can wait before
              it must report to a Ceph Monitor.

:Type: 32-bit Integer
:Default: ``120``


``osd mon report interval min``

:Description: The minimum number of seconds a Ceph OSD Daemon may wait
              from startup or another reportable event before reporting
              to a Ceph Monitor.

:Type: 32-bit Integer
:Default: ``5``
:Valid Range: Should be less than ``osd mon report interval max``


``osd mon ack timeout``

:Description: The number of seconds to wait for a Ceph Monitor to acknowledge a
              request for statistics.

:Type: 32-bit Integer
:Default: ``30``
Commit	Line	Data
7c673cae FG	1	=====================================
	2	Configuring Monitor/OSD Interaction
	3	=====================================
	4
	5	.. index:: heartbeat
	6
	7	After you have completed your initial Ceph configuration, you may deploy and run
	8	Ceph. When you execute a command such as ``ceph health`` or ``ceph -s``, the
	9	:term:`Ceph Monitor` reports on the current state of the :term:`Ceph Storage
	10	Cluster`. The Ceph Monitor knows about the Ceph Storage Cluster by requiring
	11	reports from each :term:`Ceph OSD Daemon`, and by receiving reports from Ceph
	12	OSD Daemons about the status of their neighboring Ceph OSD Daemons. If the Ceph
	13	Monitor doesn't receive reports, or if it receives reports of changes in the
	14	Ceph Storage Cluster, the Ceph Monitor updates the status of the :term:`Ceph
	15	Cluster Map`.
	16
	17	Ceph provides reasonable default settings for Ceph Monitor/Ceph OSD Daemon
	18	interaction. However, you may override the defaults. The following sections
	19	describe how Ceph Monitors and Ceph OSD Daemons interact for the purposes of
	20	monitoring the Ceph Storage Cluster.
	21
	22	.. index:: heartbeat interval
	23
	24	OSDs Check Heartbeats
	25	=====================
	26
	27	Each Ceph OSD Daemon checks the heartbeat of other Ceph OSD Daemons every 6
	28	seconds. You can change the heartbeat interval by adding an ``osd heartbeat
	29	interval`` setting under the ``[osd]`` section of your Ceph configuration file,
	30	or by setting the value at runtime. If a neighboring Ceph OSD Daemon doesn't
	31	show a heartbeat within a 20 second grace period, the Ceph OSD Daemon may
	32	consider the neighboring Ceph OSD Daemon ``down`` and report it back to a Ceph
	33	Monitor, which will update the Ceph Cluster Map. You may change this grace
	34	period by adding an ``osd heartbeat grace`` setting under the ``[mon]``
	35	and ``[osd]`` or ``[global]`` section of your Ceph configuration file,
	36	or by setting the value at runtime.
	37
	38
	39	.. ditaa:: +---------+ +---------+
	40	\| OSD 1 \| \| OSD 2 \|
	41	+---------+ +---------+
	42	\| \|
	43	\|----+ Heartbeat \|
	44	\| \| Interval \|
	45	\|<---+ Exceeded \|
	46	\| \|
	47	\| Check \|
	48	\| Heartbeat \|
	49	\|------------------->\|
	50	\| \|
	51	\|<-------------------\|
	52	\| Heart Beating \|
	53	\| \|
	54	\|----+ Heartbeat \|
	55	\| \| Interval \|
	56	\|<---+ Exceeded \|
	57	\| \|
	58	\| Check \|
	59	\| Heartbeat \|
	60	\|------------------->\|
	61	\| \|
	62	\|----+ Grace \|
	63	\| \| Period \|
	64	\|<---+ Exceeded \|
65	\| \|
66	\|----+ Mark \|
67	\| \| OSD 2 \|
68	\|<---+ Down \|
31f18b77	69
7c673cae FG	70
	71	.. index:: OSD down report
	72
	73	OSDs Report Down OSDs
	74	=====================
	75
31f18b77 FG	76	By default, two Ceph OSD Daemons from different hosts must report to the Ceph
	77	Monitors that another Ceph OSD Daemon is ``down`` before the Ceph Monitors
	78	acknowledge that the reported Ceph OSD Daemon is ``down``. But there is chance
	79	that all the OSDs reporting the failure are hosted in a rack with a bad switch
	80	which has trouble connecting to another OSD. To avoid this sort of false alarm,
	81	we consider the peers reporting a failure a proxy for a potential "subcluster"
	82	over the overall cluster that is similarly laggy. This is clearly not true in
	83	all cases, but will sometimes help us localize the grace correction to a subset
	84	of the system that is unhappy. ``mon osd reporter subtree level`` is used to
	85	group the peers into the "subcluster" by their common ancestor type in CRUSH
	86	map. By default, only two reports from different subtree are required to report
	87	another Ceph OSD Daemon ``down``. You can change the number of reporters from
	88	unique subtrees and the common ancestor type required to report a Ceph OSD
	89	Daemon ``down`` to a Ceph Monitor by adding an ``mon osd min down reporters``
	90	and ``mon osd reporter subtree level`` settings under the ``[mon]`` section of
	91	your Ceph configuration file, or by setting the value at runtime.
	92
	93
	94	.. ditaa:: +---------+ +---------+ +---------+
	95	\| OSD 1 \| \| OSD 2 \| \| Monitor \|
	96	+---------+ +---------+ +---------+
	97	\| \| \|
	98	\| OSD 3 Is Down \| \|
	99	\|---------------+--------------->\|
	100	\| \| \|
	101	\| \| \|
	102	\| \| OSD 3 Is Down \|
	103	\| \|--------------->\|
	104	\| \| \|
	105	\| \| \|
	106	\| \| \|---------+ Mark
	107	\| \| \| \| OSD 3
	108	\| \| \|<--------+ Down
7c673cae FG	109
	110
	111	.. index:: peering failure
	112
	113	OSDs Report Peering Failure
	114	===========================
	115
	116	If a Ceph OSD Daemon cannot peer with any of the Ceph OSD Daemons defined in its
	117	Ceph configuration file (or the cluster map), it will ping a Ceph Monitor for
	118	the most recent copy of the cluster map every 30 seconds. You can change the
	119	Ceph Monitor heartbeat interval by adding an ``osd mon heartbeat interval``
	120	setting under the ``[osd]`` section of your Ceph configuration file, or by
	121	setting the value at runtime.
	122
	123	.. ditaa:: +---------+ +---------+ +-------+ +---------+
	124	\| OSD 1 \| \| OSD 2 \| \| OSD 3 \| \| Monitor \|
	125	+---------+ +---------+ +-------+ +---------+
	126	\| \| \| \|
	127	\| Request To \| \| \|
31f18b77	128	\| Peer \| \| \|
7c673cae FG	129	\|-------------->\| \| \|
	130	\|<--------------\| \| \|
	131	\| Peering \| \|
	132	\| \| \|
	133	\| Request To \| \|
31f18b77	134	\| Peer \| \|
7c673cae FG	135	\|----------------------------->\| \|
	136	\| \|
	137	\|----+ OSD Monitor \|
	138	\| \| Heartbeat \|
	139	\|<---+ Interval Exceeded \|
	140	\| \|
	141	\| Failed to Peer with OSD 3 \|
	142	\|-------------------------------------------->\|
	143	\|<--------------------------------------------\|
	144	\| Receive New Cluster Map \|
31f18b77	145
7c673cae FG	146
	147	.. index:: OSD status
	148
	149	OSDs Report Their Status
	150	========================
	151
	152	If an Ceph OSD Daemon doesn't report to a Ceph Monitor, the Ceph Monitor will
	153	consider the Ceph OSD Daemon ``down`` after the ``mon osd report timeout``
	154	elapses. A Ceph OSD Daemon sends a report to a Ceph Monitor when a reportable
	155	event such as a failure, a change in placement group stats, a change in
	156	``up_thru`` or when it boots within 5 seconds. You can change the Ceph OSD
	157	Daemon minimum report interval by adding an ``osd mon report interval min``
	158	setting under the ``[osd]`` section of your Ceph configuration file, or by
31f18b77 FG	159	setting the value at runtime. A Ceph OSD Daemon sends a report to a Ceph
	160	Monitor every 120 seconds irrespective of whether any notable changes occur.
	161	You can change the Ceph Monitor report interval by adding an ``osd mon report
	162	interval max`` setting under the ``[osd]`` section of your Ceph configuration
7c673cae FG	163	file, or by setting the value at runtime.
	164
	165
	166	.. ditaa:: +---------+ +---------+
	167	\| OSD 1 \| \| Monitor \|
	168	+---------+ +---------+
	169	\| \|
	170	\|----+ Report Min \|
	171	\| \| Interval \|
	172	\|<---+ Exceeded \|
	173	\| \|
	174	\|----+ Reportable \|
	175	\| \| Event \|
	176	\|<---+ Occurs \|
	177	\| \|
	178	\| Report To \|
	179	\| Monitor \|
	180	\|------------------->\|
	181	\| \|
	182	\|----+ Report Max \|
	183	\| \| Interval \|
	184	\|<---+ Exceeded \|
	185	\| \|
	186	\| Report To \|
	187	\| Monitor \|
	188	\|------------------->\|
	189	\| \|
	190	\|----+ Monitor \|
	191	\| \| Fails \|
	192	\|<---+ \|
	193	+----+ Monitor OSD
	194	\| \| Report Timeout
	195	\|<---+ Exceeded
	196	\|
	197	+----+ Mark
	198	\| \| OSD 1
	199	\|<---+ Down
	200
	201
	202
	203
	204	Configuration Settings
	205	======================
	206
	207	When modifying heartbeat settings, you should include them in the ``[global]``
	208	section of your configuration file.
	209
	210	.. index:: monitor heartbeat
	211
	212	Monitor Settings
	213	----------------
	214
	215	``mon osd min up ratio``
	216
31f18b77	217	:Description: The minimum ratio of ``up`` Ceph OSD Daemons before Ceph will
7c673cae	218	mark Ceph OSD Daemons ``down``.
31f18b77	219
7c673cae FG	220	:Type: Double
	221	:Default: ``.3``
	222
	223
	224	``mon osd min in ratio``
	225
31f18b77	226	:Description: The minimum ratio of ``in`` Ceph OSD Daemons before Ceph will
7c673cae	227	mark Ceph OSD Daemons ``out``.
31f18b77	228
7c673cae FG	229	:Type: Double
	230	:Default: ``.75``
	231
	232
	233	``mon osd laggy halflife``
	234
	235	:Description: The number of seconds laggy estimates will decay.
	236	:Type: Integer
	237	:Default: ``60*60``
	238
	239
	240	``mon osd laggy weight``
	241
	242	:Description: The weight for new samples in laggy estimation decay.
	243	:Type: Double
	244	:Default: ``0.3``
	245
	246
31f18b77 FG	247
31f18b77 FG	248	``mon osd laggy max interval``
224ce89b	249
31f18b77 FG	250	:Description: Maximum value of ``laggy_interval`` in laggy estimations (in seconds).
	251	Monitor uses an adaptive approach to evaluate the ``laggy_interval`` of
	252	a certain OSD. This value will be used to calculate the grace time for
	253	that OSD.
	254	:Type: Integer
	255	:Default: 300
	256
7c673cae FG	257	``mon osd adjust heartbeat grace``
	258
	259	:Description: If set to ``true``, Ceph will scale based on laggy estimations.
	260	:Type: Boolean
	261	:Default: ``true``
	262
	263
	264	``mon osd adjust down out interval``
	265
	266	:Description: If set to ``true``, Ceph will scaled based on laggy estimations.
	267	:Type: Boolean
	268	:Default: ``true``
	269
	270
31f18b77	271	``mon osd auto mark in``
7c673cae	272
31f18b77	273	:Description: Ceph will mark any booting Ceph OSD Daemons as ``in``
7c673cae FG	274	the Ceph Storage Cluster.
	275
	276	:Type: Boolean
	277	:Default: ``false``
	278
	279
31f18b77	280	``mon osd auto mark auto out in``
7c673cae	281
31f18b77	282	:Description: Ceph will mark booting Ceph OSD Daemons auto marked ``out``
7c673cae	283	of the Ceph Storage Cluster as ``in`` the cluster.
31f18b77	284
7c673cae	285	:Type: Boolean
31f18b77	286	:Default: ``true``
7c673cae FG	287
7c673cae FG	288
31f18b77	289	``mon osd auto mark new in``
7c673cae	290
31f18b77	291	:Description: Ceph will mark booting new Ceph OSD Daemons as ``in`` the
7c673cae	292	Ceph Storage Cluster.
31f18b77	293
7c673cae	294	:Type: Boolean
31f18b77	295	:Default: ``true``
7c673cae FG	296
7c673cae FG	297
31f18b77	298	``mon osd down out interval``
7c673cae FG	299
	300	:Description: The number of seconds Ceph waits before marking a Ceph OSD Daemon
	301	``down`` and ``out`` if it doesn't respond.
31f18b77	302
7c673cae FG	303	:Type: 32-bit Integer
	304	:Default: ``600``
	305
	306
	307	``mon osd down out subtree limit``
	308
	309	:Description: The smallest :term:`CRUSH` unit type that Ceph will not
	310	automatically mark out. For instance, if set to ``host`` and if
	311	all OSDs of a host are down, Ceph will not automatically mark out
	312	these OSDs.
	313
	314	:Type: String
	315	:Default: ``rack``
	316
	317
31f18b77	318	``mon osd report timeout``
7c673cae	319
31f18b77	320	:Description: The grace period in seconds before declaring
7c673cae FG	321	unresponsive Ceph OSD Daemons ``down``.
	322
	323	:Type: 32-bit Integer
	324	:Default: ``900``
	325
31f18b77	326	``mon osd min down reporters``
7c673cae	327
31f18b77	328	:Description: The minimum number of Ceph OSD Daemons required to report a
7c673cae FG	329	``down`` Ceph OSD Daemon.
	330
	331	:Type: 32-bit Integer
31f18b77 FG	332	:Default: ``2``
	333
	334
	335	``mon osd reporter subtree level``
	336
	337	:Description: In which level of parent bucket the reporters are counted. The OSDs
	338	send failure reports to monitor if they find its peer is not responsive.
	339	And monitor mark the reported OSD out and then down after a grace period.
	340	:Type: String
	341	:Default: ``host``
7c673cae FG	342
	343
	344	.. index:: OSD hearbeat
	345
	346	OSD Settings
	347	------------
	348
	349	``osd heartbeat address``
	350
31f18b77	351	:Description: An Ceph OSD Daemon's network address for heartbeats.
7c673cae FG	352	:Type: Address
	353	:Default: The host address.
	354
	355
31f18b77	356	``osd heartbeat interval``
7c673cae FG	357
	358	:Description: How often an Ceph OSD Daemon pings its peers (in seconds).
	359	:Type: 32-bit Integer
	360	:Default: ``6``
	361
	362
31f18b77	363	``osd heartbeat grace``
7c673cae FG	364
	365	:Description: The elapsed time when a Ceph OSD Daemon hasn't shown a heartbeat
	366	that the Ceph Storage Cluster considers it ``down``.
	367	This setting has to be set in both the [mon] and [osd] or [global]
	368	section so that it is read by both the MON and OSD daemons.
7c673cae FG	369	:Type: 32-bit Integer
	370	:Default: ``20``
	371
	372
31f18b77	373	``osd mon heartbeat interval``
7c673cae	374
31f18b77	375	:Description: How often the Ceph OSD Daemon pings a Ceph Monitor if it has no
7c673cae FG	376	Ceph OSD Daemon peers.
	377
	378	:Type: 32-bit Integer
31f18b77	379	:Default: ``30``
7c673cae FG	380
7c673cae FG	381
31f18b77	382	``osd mon report interval max``
7c673cae FG	383
	384	:Description: The maximum time in seconds that a Ceph OSD Daemon can wait before
	385	it must report to a Ceph Monitor.
	386
	387	:Type: 32-bit Integer
31f18b77	388	:Default: ``120``
7c673cae FG	389
7c673cae FG	390
31f18b77	391	``osd mon report interval min``
7c673cae FG	392
7c673cae FG	393	:Description: The minimum number of seconds a Ceph OSD Daemon may wait
31f18b77	394	from startup or another reportable event before reporting
7c673cae FG	395	to a Ceph Monitor.
	396
	397	:Type: 32-bit Integer
	398	:Default: ``5``
31f18b77	399	:Valid Range: Should be less than ``osd mon report interval max``
7c673cae FG	400
7c673cae FG	401
31f18b77	402	``osd mon ack timeout``
7c673cae	403
31f18b77	404	:Description: The number of seconds to wait for a Ceph Monitor to acknowledge a
7c673cae FG	405	request for statistics.
	406
	407	:Type: 32-bit Integer
31f18b77	408	:Default: ``30``