+.. _mgr-administrator-guide:
ceph-mgr administrator's guide
==============================
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``.
+Place that key as file named ``keyring`` into ``mgr data`` path, which for a cluster "ceph"
+and mgr $name "foo" would be ``/var/lib/ceph/mgr/ceph-foo`` respective ``/var/lib/ceph/mgr/ceph-foo/keyring``.
Start the ceph-mgr daemon::
-----------------
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.
+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
+more than :confval:`mon_mgr_beacon_grace`, then it will be replaced
by a standby.
-If you want to pre-empt failover, you can explicitly mark a ceph-mgr
+If you want to preempt 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::
+Performance and Scalability
+---------------------------
- ceph tell mgr <command | help>
+All the mgr modules share a cache that can be enabled with
+``ceph config set mgr mgr_ttl_cache_expire_seconds <seconds>``, where seconds
+is the time to live of the cached python objects.
-Note that it is not necessary to address a particular mgr instance,
-simply ``mgr`` will pick the current active daemon.
+It is recommended to enable the cache with a 10 seconds TTL when there are 500+
+osds or 10k+ pgs as internal structures might increase in size, and cause latency
+issues when requesting large structures. As an example, an OSDMap with 1000 osds
+has a aproximate size of 4MiB. With heavy load, on a 3000 osd cluster there has
+been a 1.5x improvement enabling the cache.
-Use the ``help`` command to get a list of available commands from all
-modules.
+Furthermore, you can run ``ceph daemon mgr.${MGRNAME} perf dump`` to retrieve perf
+counters of a mgr module. In ``mgr.cache_hit`` and ``mgr.cache_miss`` you'll find the
+hit/miss ratio of the mgr cache.
-Configuration
+Using modules
-------------
-OPTION(mgr_module_path, OPT_STR, CEPH_PKGLIBDIR "/mgr") // where to load python modules from
-
-``mgr module path``
+Use the command ``ceph mgr module ls`` to see which modules are
+available, and which are currently enabled. Use ``ceph mgr module ls --format=json-pretty``
+to view detailed metadata about disabled modules. Enable or disable modules
+using the commands ``ceph mgr module enable <module>`` and
+``ceph mgr module disable <module>`` respectively.
+
+If a module is *enabled* then the active ceph-mgr daemon will load
+and execute it. In the case of modules that provide a service,
+such as an HTTP server, the module may publish its address when it
+is loaded. To see the addresses of such modules, use the command
+``ceph mgr services``.
+
+Some modules may also implement a special standby mode which runs on
+standby ceph-mgr daemons as well as the active daemon. This enables
+modules that provide services to redirect their clients to the active
+daemon, if the client tries to connect to a standby.
+
+Consult the documentation pages for individual manager modules for more
+information about what functionality each module provides.
+
+Here is an example of enabling the :term:`Dashboard` module:
+
+.. code-block:: console
+
+ $ ceph mgr module ls
+ {
+ "enabled_modules": [
+ "restful",
+ "status"
+ ],
+ "disabled_modules": [
+ "dashboard"
+ ]
+ }
+
+ $ ceph mgr module enable dashboard
+ $ ceph mgr module ls
+ {
+ "enabled_modules": [
+ "restful",
+ "status",
+ "dashboard"
+ ],
+ "disabled_modules": [
+ ]
+ }
+
+ $ ceph mgr services
+ {
+ "dashboard": "http://myserver.com:7789/",
+ "restful": "https://myserver.com:8789/"
+ }
+
+
+The first time the cluster starts, it uses the :confval:`mgr_initial_modules`
+setting to override which modules to enable. However, this setting
+is ignored through the rest of the lifetime of the cluster: only
+use it for bootstrapping. For example, before starting your
+monitor daemons for the first time, you might add a section like
+this to your ``ceph.conf``:
+
+.. code-block:: ini
+
+ [mon]
+ mgr_initial_modules = dashboard balancer
+
+Module Pool
+-----------
+
+The manager creates a pool for use by its module to store state. The name of
+this pool is ``.mgr`` (with the leading ``.`` indicating a reserved pool
+name).
+
+.. note::
+
+ Prior to Quincy, the ``devicehealth`` module created a
+ ``device_health_metrics`` pool to store device SMART statistics. With
+ Quincy, this pool is automatically renamed to be the common manager module
+ pool.
-: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"``
+Calling module commands
+-----------------------
-``mgr tick period``
+Where a module implements command line hooks, the commands will
+be accessible as ordinary Ceph commands. Ceph will automatically incorporate
+module commands into the standard CLI interface and route them appropriately to
+the module.::
-:Description: How many seconds between mgr beacons to monitors, and other
- periodic checks.
-:Type: Integer
-:Default: ``5``
+ ceph <command | help>
-``mon mgr beacon grace``
+Configuration
+-------------
-:Description: How long after last beacon should a mgr be considered failed
-:Type: Integer
-:Default: ``30``
+.. confval:: mgr_module_path
+.. confval:: mgr_initial_modules
+.. confval:: mgr_disabled_modules
+.. confval:: mgr_standby_modules
+.. confval:: mgr_data
+.. confval:: mgr_tick_period
+.. confval:: mon_mgr_beacon_grace
.. _Modifying User Capabilities: ../../rados/operations/user-management/#modify-user-capabilities
projects / ceph.git / blobdiff