[ceph.git] / ceph / doc / mgr / administrator.rst


ceph-mgr administrator's guide
==============================

Manual setup
------------

Usually, you would set up a ceph-mgr daemon using a tool such
as ceph-ansible.  These instructions describe how to set up
a ceph-mgr daemon manually.

First, create an authentication key for your daemon::

    ceph auth get-or-create mgr.$name mon 'allow profile mgr' osd 'allow *' mds 'allow *'

Place that key into ``mgr data`` path, which for a cluster "ceph"
and mgr $name "foo" would be ``/var/lib/ceph/mgr/ceph-foo``.

Start the ceph-mgr daemon::

    ceph-mgr -i $name

Check that the mgr has come up by looking at the output
of ``ceph status``, which should now include a mgr status line::

    mgr active: $name

Client authentication
---------------------

The manager is a new daemon which requires new CephX capabilities. If you upgrade
a cluster from an old version of Ceph, or use the default install/deploy tools,
your admin client should get this capability automatically. If you use tooling from
elsewhere, you may get EACCES errors when invoking certain ceph cluster commands.
To fix that, add a "mgr allow \*" stanza to your client's cephx capabilities by
`Modifying User Capabilities`_.

High availability
-----------------

In general, you should set up a ceph-mgr on each of the hosts
running a ceph-mon daemon to achieve the same level of availability. 

By default, whichever ceph-mgr instance comes up first will be made
active by the monitors, and the others will be standbys.  There is
no requirement for quorum among the ceph-mgr daemons.

If the active daemon fails to send a beacon to the monitors for
more than ``mon mgr beacon grace`` (default 30s), then it will be replaced
by a standby.

If you want to pre-empt failover, you can explicitly mark a ceph-mgr
daemon as failed using ``ceph mgr fail <mgr name>``.

Calling module commands
-----------------------

Where a module implements command line hooks, using the Ceph CLI's
``tell`` command to call them like this::

    ceph tell mgr <command | help>

Note that it is not necessary to address a particular mgr instance,
simply ``mgr`` will pick the current active daemon.

Use the ``help`` command to get a list of available commands from all
modules.

Configuration
-------------

OPTION(mgr_module_path, OPT_STR, CEPH_PKGLIBDIR "/mgr") // where to load python modules from

``mgr module path``

:Description: Path to load modules from
:Type: String
:Default: ``"<library dir>/mgr"``

``mgr data``

:Description: Path to load daemon data (such as keyring)
:Type: String
:Default: ``"/var/lib/ceph/mgr/$cluster-$id"``

``mgr tick period``

:Description: How many seconds between mgr beacons to monitors, and other
              periodic checks.
:Type: Integer
:Default: ``5``

``mon mgr beacon grace``

:Description: How long after last beacon should a mgr be considered failed
:Type: Integer
:Default: ``30``

.. _Modifying User Capabilities: ../../rados/operations/user-management/#modify-user-capabilities
Commit	Line	Data
7c673cae FG	1
	2	ceph-mgr administrator's guide
	3	==============================
	4
31f18b77 FG	5	Manual setup
31f18b77 FG	6	------------
7c673cae	7
31f18b77 FG	8	Usually, you would set up a ceph-mgr daemon using a tool such
	9	as ceph-ansible. These instructions describe how to set up
	10	a ceph-mgr daemon manually.
7c673cae	11
31f18b77 FG	12	First, create an authentication key for your daemon::
	13
	14	ceph auth get-or-create mgr.$name mon 'allow profile mgr' osd 'allow ' mds 'allow '
7c673cae FG	15
	16	Place that key into ``mgr data`` path, which for a cluster "ceph"
	17	and mgr $name "foo" would be ``/var/lib/ceph/mgr/ceph-foo``.
	18
	19	Start the ceph-mgr daemon::
	20
	21	ceph-mgr -i $name
	22
	23	Check that the mgr has come up by looking at the output
	24	of ``ceph status``, which should now include a mgr status line::
	25
	26	mgr active: $name
	27
31f18b77 FG	28	Client authentication
31f18b77 FG	29	---------------------
224ce89b	30
31f18b77 FG	31	The manager is a new daemon which requires new CephX capabilities. If you upgrade
	32	a cluster from an old version of Ceph, or use the default install/deploy tools,
	33	your admin client should get this capability automatically. If you use tooling from
	34	elsewhere, you may get EACCES errors when invoking certain ceph cluster commands.
224ce89b	35	To fix that, add a "mgr allow \*" stanza to your client's cephx capabilities by
31f18b77 FG	36	`Modifying User Capabilities`_.
31f18b77 FG	37
7c673cae FG	38	High availability
	39	-----------------
	40
	41	In general, you should set up a ceph-mgr on each of the hosts
	42	running a ceph-mon daemon to achieve the same level of availability.
	43
	44	By default, whichever ceph-mgr instance comes up first will be made
	45	active by the monitors, and the others will be standbys. There is
	46	no requirement for quorum among the ceph-mgr daemons.
	47
	48	If the active daemon fails to send a beacon to the monitors for
	49	more than ``mon mgr beacon grace`` (default 30s), then it will be replaced
	50	by a standby.
	51
	52	If you want to pre-empt failover, you can explicitly mark a ceph-mgr
	53	daemon as failed using ``ceph mgr fail <mgr name>``.
	54
	55	Calling module commands
	56	-----------------------
	57
	58	Where a module implements command line hooks, using the Ceph CLI's
	59	``tell`` command to call them like this::
	60
	61	ceph tell mgr <command \| help>
	62
	63	Note that it is not necessary to address a particular mgr instance,
	64	simply ``mgr`` will pick the current active daemon.
	65
	66	Use the ``help`` command to get a list of available commands from all
	67	modules.
	68
	69	Configuration
	70	-------------
	71
	72	OPTION(mgr_module_path, OPT_STR, CEPH_PKGLIBDIR "/mgr") // where to load python modules from
	73
	74	``mgr module path``
	75
	76	:Description: Path to load modules from
	77	:Type: String
	78	:Default: ``"<library dir>/mgr"``
	79
7c673cae FG	80	``mgr data``
	81
	82	:Description: Path to load daemon data (such as keyring)
	83	:Type: String
	84	:Default: ``"/var/lib/ceph/mgr/$cluster-$id"``
	85
31f18b77	86	``mgr tick period``
7c673cae	87
31f18b77 FG	88	:Description: How many seconds between mgr beacons to monitors, and other
31f18b77 FG	89	periodic checks.
7c673cae FG	90	:Type: Integer
	91	:Default: ``5``
	92
	93	``mon mgr beacon grace``
	94
	95	:Description: How long after last beacon should a mgr be considered failed
	96	:Type: Integer
	97	:Default: ``30``
	98
224ce89b	99	.. _Modifying User Capabilities: ../../rados/operations/user-management/#modify-user-capabilities