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
-monitor reports on the current state of the cluster. The monitor knows about the
-cluster by requiring reports from each OSD, and by receiving reports from OSDs
-about the status of their neighboring OSDs. If the monitor doesn't receive
-reports, or if it receives reports of changes in the cluster, the monitor
-updates the status of the cluster.
+: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 monitor/OSD interaction. However,
-you may override the defaults. The following sections describe how Ceph monitors
-and OSDs interact for the purposes of monitoring.
+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 OSD checks the heartbeat of other OSDs 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 an OSD doesn't show a heartbeat within a 20 second grace period, the
-cluster may consider the OSD ``down``. You may change this grace period by
-adding an ``osd heartbeat grace`` setting under the ``[osd]`` section of your
-Ceph configuration file, or by setting the value at runtime.
+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 ``[osd]`` section
+of your Ceph configuration file, or by setting the value at runtime.
.. ditaa:: +---------+ +---------+
|<---+ Down |
+.. index:: OSD down report
OSDs Report Down OSDs
=====================
-By default, an OSD must report to the monitors that another OSD is
-``down`` three times before the monitors acknowledge that the reported
-OSD is ``down``. You can change the minimum number of ``osd down``
-reports by adding an ``mon osd min down reports`` setting (``osd min
-down reports`` prior to v0.62) under the ``[mon]`` section of your
-Ceph configuration file, or by setting the value at runtime. By
-default, only one OSD is required to report another OSD down. You can
-change the number of OSDs required to report a monitor down by adding
-an ``mon osd min down reporters`` setting (``osd min down reporters''
-prior to v0.62) under the ``[mon]`` section of your Ceph configuration
-file, or by setting the value at runtime.
+By default, a Ceph OSD Daemon must report to the Ceph Monitors that another Ceph
+OSD Daemon is ``down`` three times before the Ceph Monitors acknowledge that the
+reported Ceph OSD Daemon is ``down``. You can change the minimum number of
+``osd down`` reports by adding an ``mon osd min down reports`` setting (``osd
+min down reports`` prior to v0.62) under the ``[mon]`` section of your Ceph
+configuration file, or by setting the value at runtime. By default, only one
+Ceph OSD Daemon is required to report another Ceph OSD Daemon ``down``. You can
+change the number of Ceph OSD Daemones required to report a Ceph OSD Daemon
+``down`` to a Ceph Monitor by adding an ``mon osd min down reporters`` setting
+(``osd min down reporters'' prior to v0.62) under the ``[mon]`` section of your
+Ceph configuration file, or by setting the value at runtime.
.. ditaa:: +---------+ +---------+
| |<---------+ Down
+.. index:: peering failure
OSDs Report Peering Failure
===========================
-If an OSD cannot peer with any of the OSDs defined in its Ceph configuration
-file, it will ping the monitor for the most recent copy of the cluster map every
-30 seconds. You can change the 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.
+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 |
| Receive New Cluster Map |
+.. index:: OSD status
OSDs Report Their Status
========================
-If an OSD doesn't report to the monitor once at least every 120 seconds, the
-monitor will consider the OSD ``down``. You can change the 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. The OSD attempts to report on its status every 30 seconds. You can
-change the OSD 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.
+If an Ceph OSD Daemon doesn't report to a Ceph Monitor once at least every 120
+seconds, the Ceph Monitor will consider the Ceph OSD Daemon ``down``. 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. The Ceph OSD Daemon attempts to report on its
+status every 30 seconds. You can change the Ceph OSD Daemon 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.
.. ditaa:: +---------+ +---------+
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`` OSDs before Ceph will mark
- OSDs ``down``.
+: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`` OSDs before Ceph will mark
- OSDs ``out``.
+:Description: The minimum ratio of ``in`` Ceph OSD Daemons before Ceph will
+ mark Ceph OSD Daemons ``out``.
:Type: Double
:Default: ``.3``
``mon osd auto mark in``
-:Description: Ceph will mark any booting OSDs as ``in`` the cluster.
+: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 OSDs auto marked ``out`` of the cluster
- as ``in`` the cluster.
+: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 OSDs as ``in`` the cluster.
+: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 an OSD ``down``
- and ``out`` if it doesn't respond.
+: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: ``300``
``mon osd downout subtree limit``
-:Description: The largest CRUSH unit type that Ceph will
+:Description: The largest :term:`CRUSH` unit type that Ceph will
automatically mark ``out``.
:Type: String
``mon osd report timeout``
-:Description: The grace period in seconds before declaring unresponsive OSDs ``down``.
+: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 OSDs required to report a ``down`` OSD.
+:Description: The minimum number of Ceph OSD Daemons required to report a
+ ``down`` Ceph OSD Daemon.
+
:Type: 32-bit Integer
:Default: ``1``
``mon osd min down reports``
-:Description: The minimum number of times an OSD must report that another
- is ``down``.
+:Description: The minimum number of times a Ceph OSD Daemon must report
+ that another Ceph OSD Daemon is ``down``.
:Type: 32-bit Integer
:Default: ``3``
-
+.. index:: OSD hearbeat
OSD Settings
------------
``osd heartbeat address``
-:Description: An OSD's network address for heartbeats.
+:Description: An Ceph OSD Daemon's network address for heartbeats.
:Type: Address
:Default: The host address.
``osd heartbeat interval``
-:Description: How often an OSD pings its peers (in seconds).
+: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 an OSD hasn't shown a heartbeat that the
- cluster considers it ``down``.
+:Description: The elapsed time when a Ceph OSD Daemon hasn't shown a heartbeat
+ that the Ceph Storage Cluster considers it ``down``.
:Type: 32-bit Integer
:Default: ``20``
``osd mon heartbeat interval``
-:Description: How often the OSD pings a monitor if it has no OSD peers.
+: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 for an OSD to report to a monitor
- before the monitor considers the OSD ``down``.
+:Description: The maximum time in seconds for an Ceph OSD Daemon to report to
+ a Ceph Monitor before the Ceph Monitor considers the
+ Ceph OSD Daemon ``down``.
:Type: 32-bit Integer
:Default: ``120``
``osd mon report interval min``
-:Description: The minimum number of seconds for an OSD to report to a monitor
- to avoid the monitor considering the OSD ``down``.
+:Description: The minimum number of seconds for a Ceph OSD Daemon to report
+ to a Ceph Monitor to prevent the Ceph Monitor from considering
+ the Ceph OSD Daemon ``down``.
:Type: 32-bit Integer
:Default: ``5``
``osd mon ack timeout``
-:Description: The number of seconds to wait for a monitor to acknowledge a
+:Description: The number of seconds to wait for a Ceph Monitor to acknowledge a
request for statistics.
:Type: 32-bit Integer
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