[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, the commands will
be accessible as ordinary Ceph commands::

    ceph <command | help>

If you would like to see the list of commands handled by the
manager (where normal ``ceph help`` would show all mon and mgr commands),
you can send a command directly to the manager daemon::

    ceph tell mgr help

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

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
c07f9fc5 FG	58	Where a module implements command line hooks, the commands will
c07f9fc5 FG	59	be accessible as ordinary Ceph commands::
7c673cae	60
c07f9fc5 FG	61	ceph <command \| help>
	62
	63	If you would like to see the list of commands handled by the
	64	manager (where normal ``ceph help`` would show all mon and mgr commands),
	65	you can send a command directly to the manager daemon::
	66
	67	ceph tell mgr help
7c673cae FG	68
	69	Note that it is not necessary to address a particular mgr instance,
	70	simply ``mgr`` will pick the current active daemon.
	71
7c673cae FG	72	Configuration
	73	-------------
	74
	75	OPTION(mgr_module_path, OPT_STR, CEPH_PKGLIBDIR "/mgr") // where to load python modules from
	76
	77	``mgr module path``
	78
	79	:Description: Path to load modules from
	80	:Type: String
	81	:Default: ``"<library dir>/mgr"``
	82
7c673cae FG	83	``mgr data``
	84
	85	:Description: Path to load daemon data (such as keyring)
	86	:Type: String
	87	:Default: ``"/var/lib/ceph/mgr/$cluster-$id"``
	88
31f18b77	89	``mgr tick period``
7c673cae	90
31f18b77 FG	91	:Description: How many seconds between mgr beacons to monitors, and other
31f18b77 FG	92	periodic checks.
7c673cae FG	93	:Type: Integer
	94	:Default: ``5``
	95
	96	``mon mgr beacon grace``
	97
	98	:Description: How long after last beacon should a mgr be considered failed
	99	:Type: Integer
	100	:Default: ``30``
	101
224ce89b	102	.. _Modifying User Capabilities: ../../rados/operations/user-management/#modify-user-capabilities