initial code repo

This patch creates initial code repo.

For ceph, luminous stable release will be used for base code,
and next changes and optimization for ceph will be added to it.

For opensds, currently any changes can be upstreamed into original
opensds repo (https://github.com/opensds/opensds), and so stor4nfv
will directly clone opensds code to deploy stor4nfv environment.
And the scripts for deployment based on ceph and opensds will be
put into 'ci' directory.

Change-Id: I46a32218884c75dda2936337604ff03c554648e4
Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com>

1 files changed, 1222 insertions, 0 deletions

diff --git a/src/ceph/doc/rados/configuration/mon-config-ref.rst b/src/ceph/doc/rados/configuration/mon-config-ref.rst
new file mode 100644
index 0000000..6c8e92b
--- /dev/null
+++ b/src/ceph/doc/rados/configuration/mon-config-ref.rst
@@ -0,0 +1,1222 @@
+==========================
+ Monitor Config Reference
+==========================
+
+Understanding how to configure a :term:`Ceph Monitor` is an important part of
+building a reliable :term:`Ceph Storage Cluster`. **All Ceph Storage Clusters
+have at least one monitor**. A monitor configuration usually remains fairly
+consistent, but you can add, remove or replace a monitor in a cluster. See
+`Adding/Removing a Monitor`_ and `Add/Remove a Monitor (ceph-deploy)`_ for
+details.
+
+
+.. index:: Ceph Monitor; Paxos
+
+Background
+==========
+
+Ceph Monitors maintain a "master copy" of the :term:`cluster map`, which means a
+:term:`Ceph Client` can determine the location of all Ceph Monitors, Ceph OSD
+Daemons, and Ceph Metadata Servers just by connecting to one Ceph Monitor and
+retrieving a current cluster map. Before Ceph Clients can read from or write to
+Ceph OSD Daemons or Ceph Metadata Servers, they must connect to a Ceph Monitor
+first. With a current copy of the cluster map and the CRUSH algorithm, a Ceph
+Client can compute the location for any object. The ability to compute object
+locations allows a Ceph Client to talk directly to Ceph OSD Daemons, which is a
+very important aspect of Ceph's high scalability and performance. See 
+`Scalability and High Availability`_ for additional details.
+
+The primary role of the Ceph Monitor is to maintain a master copy of the cluster
+map. Ceph Monitors also provide authentication and logging services. Ceph
+Monitors write all changes in the monitor services to a single Paxos instance,
+and Paxos writes the changes to a key/value store for strong consistency. Ceph
+Monitors can query the most recent version of the cluster map during sync
+operations. Ceph Monitors leverage the key/value store's snapshots and iterators
+(using leveldb) to perform store-wide synchronization.
+
+.. ditaa:: 
+
+ /-------------\               /-------------\
+ |   Monitor   | Write Changes |    Paxos    |
+ |   cCCC      +-------------->+   cCCC      |
+ |             |               |             |
+ +-------------+               \------+------/
+ |    Auth     |                      |
+ +-------------+                      | Write Changes
+ |    Log      |                      |
+ +-------------+                      v
+ | Monitor Map |               /------+------\
+ +-------------+               | Key / Value |
+ |   OSD Map   |               |    Store    |
+ +-------------+               |  cCCC       |
+ |   PG Map    |               \------+------/
+ +-------------+                      ^
+ |   MDS Map   |                      | Read Changes
+ +-------------+                      |
+ |    cCCC     |*---------------------+
+ \-------------/
+
+
+.. deprecated:: version 0.58
+
+In Ceph versions 0.58 and earlier, Ceph Monitors use a Paxos instance for
+each service and store the map as a file. 
+
+.. index:: Ceph Monitor; cluster map
+
+Cluster Maps
+------------
+
+The cluster map is a composite of maps, including the monitor map, the OSD map,
+the placement group map and the metadata server map. The cluster map tracks a
+number of important things: which processes are ``in`` the Ceph Storage Cluster;
+which processes that are ``in`` the Ceph Storage Cluster are ``up`` and running
+or ``down``; whether, the placement groups are ``active`` or ``inactive``, and
+``clean`` or in some other state; and, other details that reflect the current
+state of the cluster such as the total amount of storage space, and the amount
+of storage used.
+
+When there is a significant change in the state of the cluster--e.g., a Ceph OSD
+Daemon goes down, a placement group falls into a degraded state, etc.--the
+cluster map gets updated to reflect the current state of the cluster.
+Additionally, the Ceph Monitor also maintains a history of the prior states of
+the cluster. The monitor map, OSD map, placement group map and metadata server
+map each maintain a history of their map versions. We call each version an
+"epoch."
+
+When operating your Ceph Storage Cluster, keeping track of these states is an
+important part of your system administration duties. See `Monitoring a Cluster`_
+and `Monitoring OSDs and PGs`_ for additional details.
+
+.. index:: high availability; quorum
+
+Monitor Quorum
+--------------
+
+Our Configuring ceph section provides a trivial `Ceph configuration file`_ that
+provides for one monitor in the test cluster. A cluster will run fine with a
+single monitor; however, **a single monitor is a single-point-of-failure**. To
+ensure high availability in a production Ceph Storage Cluster, you should run
+Ceph with multiple monitors so that the failure of a single monitor **WILL NOT**
+bring down your entire cluster.
+
+When a Ceph Storage Cluster runs multiple Ceph Monitors for high availability,
+Ceph Monitors use `Paxos`_ to establish consensus about the master cluster map.
+A consensus requires a majority of monitors running to establish a quorum for
+consensus about the cluster map (e.g., 1; 2 out of 3; 3 out of 5; 4 out of 6;
+etc.).
+
+``mon force quorum join``
+
+:Description: Force monitor to join quorum even if it has been previously removed from the map
+:Type: Boolean
+:Default: ``False``
+
+.. index:: Ceph Monitor; consistency
+
+Consistency
+-----------
+
+When you add monitor settings to your Ceph configuration file, you need to be
+aware of some of the architectural aspects of Ceph Monitors. **Ceph imposes
+strict consistency requirements** for a Ceph monitor when discovering another
+Ceph Monitor within the cluster. Whereas, Ceph Clients and other Ceph daemons
+use the Ceph configuration file to discover monitors, monitors discover each
+other using the monitor map (monmap), not the Ceph configuration file.
+
+A Ceph Monitor always refers to the local copy of the monmap when discovering
+other Ceph Monitors in the Ceph Storage Cluster. Using the monmap instead of the
+Ceph configuration file avoids errors that could break the cluster (e.g., typos
+in ``ceph.conf`` when specifying a monitor address or port). Since monitors use
+monmaps for discovery and they share monmaps with clients and other Ceph
+daemons, **the monmap provides monitors with a strict guarantee that their
+consensus is valid.**
+
+Strict consistency also applies to updates to the monmap. As with any other
+updates on the Ceph Monitor, changes to the monmap always run through a
+distributed consensus algorithm called `Paxos`_. The Ceph Monitors must agree on
+each update to the monmap, such as adding or removing a Ceph Monitor, to ensure
+that each monitor in the quorum has the same version of the monmap. Updates to
+the monmap are incremental so that Ceph Monitors have the latest agreed upon
+version, and a set of previous versions. Maintaining a history enables a Ceph
+Monitor that has an older version of the monmap to catch up with the current
+state of the Ceph Storage Cluster.
+
+If Ceph Monitors discovered each other through the Ceph configuration file
+instead of through the monmap, it would introduce additional risks because the
+Ceph configuration files are not updated and distributed automatically. Ceph
+Monitors might inadvertently use an older Ceph configuration file, fail to
+recognize a Ceph Monitor, fall out of a quorum, or develop a situation where
+`Paxos`_ is not able to determine the current state of the system accurately.
+
+
+.. index:: Ceph Monitor; bootstrapping monitors
+
+Bootstrapping Monitors
+----------------------
+
+In most configuration and deployment cases, tools that deploy Ceph may help
+bootstrap the Ceph Monitors by generating a monitor map for you (e.g.,
+``ceph-deploy``, etc). A Ceph Monitor requires a few explicit
+settings:
+
+- **Filesystem ID**: The ``fsid`` is the unique identifier for your
+  object store. Since you can run multiple clusters on the same
+  hardware, you must specify the unique ID of the object store when
+  bootstrapping a monitor.  Deployment tools usually do this for you
+  (e.g., ``ceph-deploy`` can call a tool like ``uuidgen``), but you
+  may specify the ``fsid`` manually too.
+  
+- **Monitor ID**: A monitor ID is a unique ID assigned to each monitor within 
+  the cluster. It is an alphanumeric value, and by convention the identifier 
+  usually follows an alphabetical increment (e.g., ``a``, ``b``, etc.). This 
+  can be set in a Ceph configuration file (e.g., ``[mon.a]``, ``[mon.b]``, etc.), 
+  by a deployment tool, or using the ``ceph`` commandline.
+
+- **Keys**: The monitor must have secret keys. A deployment tool such as 
+  ``ceph-deploy`` usually does this for you, but you may
+  perform this step manually too. See `Monitor Keyrings`_ for details.
+
+For additional details on bootstrapping, see `Bootstrapping a Monitor`_.
+
+.. index:: Ceph Monitor; configuring monitors
+
+Configuring Monitors
+====================
+
+To apply configuration settings to the entire cluster, enter the configuration
+settings under ``[global]``. To apply configuration settings to all monitors in
+your cluster, enter the configuration settings under ``[mon]``. To apply
+configuration settings to specific monitors, specify the monitor instance 
+(e.g., ``[mon.a]``). By convention, monitor instance names use alpha notation.
+
+.. code-block:: ini
+
+	[global]
+
+	[mon]		
+		
+	[mon.a]
+		
+	[mon.b]
+		
+	[mon.c]
+
+
+Minimum Configuration
+---------------------
+
+The bare minimum monitor settings for a Ceph monitor via the Ceph configuration
+file include a hostname and a monitor address for each monitor. You can configure
+these under ``[mon]`` or under the entry for a specific monitor.
+
+.. code-block:: ini
+
+	[mon]
+		mon host = hostname1,hostname2,hostname3
+		mon addr = 10.0.0.10:6789,10.0.0.11:6789,10.0.0.12:6789
+
+
+.. code-block:: ini
+
+	[mon.a]
+		host = hostname1
+		mon addr = 10.0.0.10:6789
+
+See the `Network Configuration Reference`_ for details.
+
+.. note:: This minimum configuration for monitors assumes that a deployment 
+   tool generates the ``fsid`` and the ``mon.`` key for you.
+
+Once you deploy a Ceph cluster, you **SHOULD NOT** change the IP address of
+the monitors. However, if you decide to change the monitor's IP address, you
+must follow a specific procedure. See `Changing a Monitor's IP Address`_ for
+details.
+
+Monitors can also be found by clients using DNS SRV records. See `Monitor lookup through DNS`_ for details.
+
+Cluster ID
+----------
+
+Each Ceph Storage Cluster has a unique identifier (``fsid``). If specified, it
+usually appears under the ``[global]`` section of the configuration file.
+Deployment tools usually generate the ``fsid`` and store it in the monitor map,
+so the value may not appear in a configuration file. The ``fsid`` makes it
+possible to run daemons for multiple clusters on the same hardware.
+
+``fsid``
+
+:Description: The cluster ID. One per cluster.
+:Type: UUID
+:Required: Yes.
+:Default: N/A. May be generated by a deployment tool if not specified.
+
+.. note:: Do not set this value if you use a deployment tool that does
+   it for you.
+
+
+.. index:: Ceph Monitor; initial members
+
+Initial Members
+---------------
+
+We recommend running a production Ceph Storage Cluster with at least three Ceph
+Monitors to ensure high availability. When you run multiple monitors, you may
+specify the initial monitors that must be members of the cluster in order to
+establish a quorum. This may reduce the time it takes for your cluster to come
+online.
+
+.. code-block:: ini
+
+	[mon]		
+		mon initial members = a,b,c
+
+
+``mon initial members``
+
+:Description: The IDs of initial monitors in a cluster during startup. If 
+              specified, Ceph requires an odd number of monitors to form an 
+              initial quorum (e.g., 3). 
+
+:Type: String
+:Default: None
+
+.. note:: A *majority* of monitors in your cluster must be able to reach 
+   each other in order to establish a quorum. You can decrease the initial 
+   number of monitors to establish a quorum with this setting.
+
+.. index:: Ceph Monitor; data path
+
+Data
+----
+
+Ceph provides a default path where Ceph Monitors store data. For optimal
+performance in a production Ceph Storage Cluster, we recommend running Ceph
+Monitors on separate hosts and drives from Ceph OSD Daemons. As leveldb is using
+``mmap()`` for writing the data, Ceph Monitors flush their data from memory to disk
+very often, which can interfere with Ceph OSD Daemon workloads if the data
+store is co-located with the OSD Daemons.
+
+In Ceph versions 0.58 and earlier, Ceph Monitors store their data in files. This 
+approach allows users to inspect monitor data with common tools like ``ls``
+and ``cat``. However, it doesn't provide strong consistency.
+
+In Ceph versions 0.59 and later, Ceph Monitors store their data as key/value
+pairs. Ceph Monitors require `ACID`_ transactions. Using a data store prevents
+recovering Ceph Monitors from running corrupted versions through Paxos, and it
+enables multiple modification operations in one single atomic batch, among other
+advantages.
+
+Generally, we do not recommend changing the default data location. If you modify
+the default location, we recommend that you make it uniform across Ceph Monitors
+by setting it in the ``[mon]`` section of the configuration file.
+
+
+``mon data`` 
+
+:Description: The monitor's data location.
+:Type: String
+:Default: ``/var/lib/ceph/mon/$cluster-$id``
+
+
+``mon data size warn``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log when the monitor's data
+              store goes over 15GB.
+:Type: Integer
+:Default: 15*1024*1024*1024*
+
+
+``mon data avail warn``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log when the available disk
+              space of monitor's data store is lower or equal to this
+              percentage.
+:Type: Integer
+:Default: 30
+
+
+``mon data avail crit``
+
+:Description: Issue a ``HEALTH_ERR`` in cluster log when the available disk
+              space of monitor's data store is lower or equal to this
+              percentage.
+:Type: Integer
+:Default: 5
+
+
+``mon warn on cache pools without hit sets``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log if a cache pool does not
+              have the hitset type set set.
+              See `hit set type <../operations/pools#hit-set-type>`_ for more
+              details.
+:Type: Boolean
+:Default: True
+
+
+``mon warn on crush straw calc version zero``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log if the CRUSH's
+              ``straw_calc_version`` is zero. See
+              `CRUSH map tunables <../operations/crush-map#tunables>`_ for
+              details.
+:Type: Boolean
+:Default: True
+
+
+``mon warn on legacy crush tunables``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log if
+              CRUSH tunables are too old (older than ``mon_min_crush_required_version``)
+:Type: Boolean
+:Default: True
+
+
+``mon crush min required version``
+
+:Description: The minimum tunable profile version required by the cluster.
+              See
+              `CRUSH map tunables <../operations/crush-map#tunables>`_ for
+              details.
+:Type: String
+:Default: ``firefly``
+
+
+``mon warn on osd down out interval zero``
+
+:Description: Issue a ``HEALTH_WARN`` in cluster log if
+              ``mon osd down out interval`` is zero. Having this option set to
+              zero on the leader acts much like the ``noout`` flag. It's hard
+              to figure out what's going wrong with clusters witout the
+              ``noout`` flag set but acting like that just the same, so we
+              report a warning in this case.
+:Type: Boolean
+:Default: True
+
+
+``mon cache target full warn ratio``
+
+:Description: Position between pool's ``cache_target_full`` and
+              ``target_max_object`` where we start warning
+:Type: Float
+:Default: ``0.66``
+
+
+``mon health data update interval``
+
+:Description: How often (in seconds) the monitor in quorum shares its health
+              status with its peers. (negative number disables it)
+:Type: Float
+:Default: ``60``
+
+
+``mon health to clog``
+
+:Description: Enable sending health summary to cluster log periodically.
+:Type: Boolean
+:Default: True
+
+
+``mon health to clog tick interval``
+
+:Description: How often (in seconds) the monitor send health summary to cluster
+              log (a non-positive number disables it). If current health summary
+              is empty or identical to the last time, monitor will not send it
+              to cluster log.
+:Type: Integer
+:Default: 3600
+
+
+``mon health to clog interval``
+
+:Description: How often (in seconds) the monitor send health summary to cluster
+              log (a non-positive number disables it). Monitor will always
+              send the summary to cluster log no matter if the summary changes
+              or not.
+:Type: Integer
+:Default: 60
+
+
+
+.. index:: Ceph Storage Cluster; capacity planning, Ceph Monitor; capacity planning
+
+Storage Capacity
+----------------
+
+When a Ceph Storage Cluster gets close to its maximum capacity (i.e., ``mon osd
+full ratio``),  Ceph prevents you from writing to or reading from Ceph OSD
+Daemons as a safety measure to prevent data loss. Therefore, letting a
+production Ceph Storage Cluster approach its full ratio is not a good practice,
+because it sacrifices high availability. The default full ratio is ``.95``, or
+95% of capacity. This a very aggressive setting for a test cluster with a small
+number of OSDs.
+
+.. tip:: When monitoring your cluster, be alert to warnings related to the 
+   ``nearfull`` ratio. This means that a failure of some OSDs could result
+   in a temporary service disruption if one or more OSDs fails. Consider adding
+   more OSDs to increase storage capacity.
+
+A common scenario for test clusters involves a system administrator removing a
+Ceph OSD Daemon from the Ceph Storage Cluster to watch the cluster rebalance;
+then, removing another Ceph OSD Daemon, and so on until the Ceph Storage Cluster
+eventually reaches the full ratio and locks up. We recommend a bit of capacity
+planning even with a test cluster. Planning enables you to gauge how much spare
+capacity you will need in order to maintain high availability. Ideally, you want
+to plan for a series of Ceph OSD Daemon failures where the cluster can recover
+to an ``active + clean`` state without replacing those Ceph OSD Daemons
+immediately. You can run a cluster in an ``active + degraded`` state, but this
+is not ideal for normal operating conditions.
+
+The following diagram depicts a simplistic Ceph Storage Cluster containing 33
+Ceph Nodes with one Ceph OSD Daemon per host, each Ceph OSD Daemon reading from
+and writing to a 3TB drive. So this exemplary Ceph Storage Cluster has a maximum
+actual capacity of 99TB. With a ``mon osd full ratio`` of ``0.95``, if the Ceph
+Storage Cluster falls to 5TB of remaining capacity, the cluster will not allow
+Ceph Clients to read and write data. So the Ceph Storage Cluster's operating
+capacity is 95TB, not 99TB.
+
+.. ditaa::
+
+ +--------+  +--------+  +--------+  +--------+  +--------+  +--------+
+ | Rack 1 |  | Rack 2 |  | Rack 3 |  | Rack 4 |  | Rack 5 |  | Rack 6 |
+ | cCCC   |  | cF00   |  | cCCC   |  | cCCC   |  | cCCC   |  | cCCC   |
+ +--------+  +--------+  +--------+  +--------+  +--------+  +--------+
+ | OSD 1  |  | OSD 7  |  | OSD 13 |  | OSD 19 |  | OSD 25 |  | OSD 31 |
+ +--------+  +--------+  +--------+  +--------+  +--------+  +--------+
+ | OSD 2  |  | OSD 8  |  | OSD 14 |  | OSD 20 |  | OSD 26 |  | OSD 32 |
+ +--------+  +--------+  +--------+  +--------+  +--------+  +--------+
+ | OSD 3  |  | OSD 9  |  | OSD 15 |  | OSD 21 |  | OSD 27 |  | OSD 33 |
+ +--------+  +--------+  +--------+  +--------+  +--------+  +--------+
+ | OSD 4  |  | OSD 10 |  | OSD 16 |  | OSD 22 |  | OSD 28 |  | Spare  | 
+ +--------+  +--------+  +--------+  +--------+  +--------+  +--------+
+ | OSD 5  |  | OSD 11 |  | OSD 17 |  | OSD 23 |  | OSD 29 |  | Spare  |
+ +--------+  +--------+  +--------+  +--------+  +--------+  +--------+
+ | OSD 6  |  | OSD 12 |  | OSD 18 |  | OSD 24 |  | OSD 30 |  | Spare  |
+ +--------+  +--------+  +--------+  +--------+  +--------+  +--------+
+
+It is normal in such a cluster for one or two OSDs to fail. A less frequent but
+reasonable scenario involves a rack's router or power supply failing, which
+brings down multiple OSDs simultaneously (e.g., OSDs 7-12). In such a scenario,
+you should still strive for a cluster that can remain operational and achieve an
+``active + clean`` state--even if that means adding a few hosts with additional
+OSDs in short order. If your capacity utilization is too high, you may not lose
+data, but you could still sacrifice data availability while resolving an outage
+within a failure domain if capacity utilization of the cluster exceeds the full
+ratio. For this reason, we recommend at least some rough capacity planning.
+
+Identify two numbers for your cluster:
+
+#. The number of OSDs. 
+#. The total capacity of the cluster 
+
+If you divide the total capacity of your cluster by the number of OSDs in your
+cluster, you will find the mean average capacity of an OSD within your cluster.
+Consider multiplying that number by the number of OSDs you expect will fail
+simultaneously during normal operations (a relatively small number). Finally
+multiply the capacity of the cluster by the full ratio to arrive at a maximum
+operating capacity; then, subtract the number of amount of data from the OSDs
+you expect to fail to arrive at a reasonable full ratio. Repeat the foregoing
+process with a higher number of OSD failures (e.g., a rack of OSDs) to arrive at
+a reasonable number for a near full ratio.
+
+.. code-block:: ini
+
+	[global]
+		
+		mon osd full ratio = .80
+		mon osd backfillfull ratio = .75
+		mon osd nearfull ratio = .70
+
+
+``mon osd full ratio`` 
+
+:Description: The percentage of disk space used before an OSD is 
+              considered ``full``.
+
+:Type: Float
+:Default: ``.95``
+
+
+``mon osd backfillfull ratio``
+
+:Description: The percentage of disk space used before an OSD is
+              considered too ``full`` to backfill.
+
+:Type: Float
+:Default: ``.90``
+
+
+``mon osd nearfull ratio`` 
+
+:Description: The percentage of disk space used before an OSD is 
+              considered ``nearfull``.
+
+:Type: Float
+:Default: ``.85``
+
+
+.. tip:: If some OSDs are nearfull, but others have plenty of capacity, you 
+         may have a problem with the CRUSH weight for the nearfull OSDs.
+
+.. index:: heartbeat
+
+Heartbeat
+---------
+
+Ceph monitors know about the cluster by requiring reports from each OSD, and by
+receiving reports from OSDs about the status of their neighboring OSDs. Ceph
+provides reasonable default settings for monitor/OSD interaction; however,  you
+may modify them as needed. See `Monitor/OSD Interaction`_ for details.
+
+
+.. index:: Ceph Monitor; leader, Ceph Monitor; provider, Ceph Monitor; requester, Ceph Monitor; synchronization
+
+Monitor Store Synchronization
+-----------------------------
+
+When you run a production cluster with multiple monitors (recommended), each
+monitor checks to see if a neighboring monitor has a more recent version of the
+cluster map (e.g., a map in a neighboring monitor with one or more epoch numbers
+higher than the most current epoch in the map of the instant monitor).
+Periodically, one monitor in the cluster may fall behind the other monitors to
+the point where it must leave the quorum, synchronize to retrieve the most
+current information about the cluster, and then rejoin the quorum. For the
+purposes of synchronization, monitors may assume one of three roles: 
+
+#. **Leader**: The `Leader` is the first monitor to achieve the most recent
+   Paxos version of the cluster map.
+
+#. **Provider**: The `Provider` is a monitor that has the most recent version
+   of the cluster map, but wasn't the first to achieve the most recent version.
+
+#. **Requester:** A `Requester` is a monitor that has fallen behind the leader
+   and must synchronize in order to retrieve the most recent information about
+   the cluster before it can rejoin the quorum.
+
+These roles enable a leader to delegate synchronization duties to a provider,
+which prevents synchronization requests from overloading the leader--improving
+performance. In the following diagram, the requester has learned that it has
+fallen behind the other monitors. The requester asks the leader to synchronize,
+and the leader tells the requester to synchronize with a provider.
+
+
+.. ditaa:: +-----------+          +---------+          +----------+
+           | Requester |          | Leader  |          | Provider |
+           +-----------+          +---------+          +----------+
+                  |                    |                     |
+                  |                    |                     |
+                  | Ask to Synchronize |                     |
+                  |------------------->|                     |
+                  |                    |                     |
+                  |<-------------------|                     |
+                  | Tell Requester to  |                     |
+                  | Sync with Provider |                     |
+                  |                    |                     |
+                  |               Synchronize                |
+                  |--------------------+-------------------->|
+                  |                    |                     |
+                  |<-------------------+---------------------|
+                  |        Send Chunk to Requester           |
+                  |         (repeat as necessary)            |
+                  |    Requester Acks Chuck to Provider      |
+                  |--------------------+-------------------->|
+                  |                    |
+                  |   Sync Complete    |
+                  |    Notification    |
+                  |------------------->|
+                  |                    |
+                  |<-------------------|
+                  |        Ack         |
+                  |                    |
+
+
+Synchronization always occurs when a new monitor joins the cluster. During
+runtime operations, monitors may receive updates to the cluster map at different
+times. This means the leader and provider roles may migrate from one monitor to
+another. If this happens while synchronizing (e.g., a provider falls behind the
+leader), the provider can terminate synchronization with a requester.
+
+Once synchronization is complete, Ceph requires trimming across the cluster. 
+Trimming requires that the placement groups are ``active + clean``.
+
+
+``mon sync trim timeout``
+
+:Description: 
+:Type: Double
+:Default: ``30.0``
+
+
+``mon sync heartbeat timeout``
+
+:Description: 
+:Type: Double
+:Default: ``30.0``
+
+
+``mon sync heartbeat interval``
+
+:Description: 
+:Type: Double
+:Default: ``5.0``
+
+
+``mon sync backoff timeout``
+
+:Description: 
+:Type: Double
+:Default: ``30.0``
+
+
+``mon sync timeout``
+
+:Description: Number of seconds the monitor will wait for the next update
+              message from its sync provider before it gives up and bootstrap
+              again.
+:Type: Double
+:Default: ``30.0``
+
+
+``mon sync max retries``
+
+:Description: 
+:Type: Integer
+:Default: ``5``
+
+
+``mon sync max payload size``
+
+:Description: The maximum size for a sync payload (in bytes).
+:Type: 32-bit Integer
+:Default: ``1045676``
+
+
+``paxos max join drift``
+
+:Description: The maximum Paxos iterations before we must first sync the
+              monitor data stores. When a monitor finds that its peer is too
+              far ahead of it, it will first sync with data stores before moving
+              on.
+:Type: Integer
+:Default: ``10``
+
+``paxos stash full interval``
+
+:Description: How often (in commits) to stash a full copy of the PaxosService state.
+              Current this setting only affects ``mds``, ``mon``, ``auth`` and ``mgr``
+              PaxosServices.
+:Type: Integer
+:Default: 25
+
+``paxos propose interval``
+
+:Description: Gather updates for this time interval before proposing 
+              a map update.
+:Type: Double
+:Default: ``1.0``
+
+
+``paxos min``
+
+:Description: The minimum number of paxos states to keep around
+:Type: Integer
+:Default: 500
+
+
+``paxos min wait``
+
+:Description: The minimum amount of time to gather updates after a period of 
+              inactivity.
+:Type: Double
+:Default: ``0.05``
+
+
+``paxos trim min``
+
+:Description: Number of extra proposals tolerated before trimming
+:Type: Integer
+:Default: 250
+
+
+``paxos trim max``
+
+:Description: The maximum number of extra proposals to trim at a time
+:Type: Integer
+:Default: 500
+
+
+``paxos service trim min``
+
+:Description: The minimum amount of versions to trigger a trim (0 disables it)
+:Type: Integer
+:Default: 250
+
+
+``paxos service trim max``
+
+:Description: The maximum amount of versions to trim during a single proposal (0 disables it)
+:Type: Integer
+:Default: 500
+
+
+``mon max log epochs``
+
+:Description: The maximum amount of log epochs to trim during a single proposal
+:Type: Integer
+:Default: 500
+
+
+``mon max pgmap epochs``
+
+:Description: The maximum amount of pgmap epochs to trim during a single proposal
+:Type: Integer
+:Default: 500
+
+
+``mon mds force trim to``
+
+:Description: Force monitor to trim mdsmaps to this point (0 disables it.
+              dangerous, use with care)
+:Type: Integer
+:Default: 0
+
+
+``mon osd force trim to``
+
+:Description: Force monitor to trim osdmaps to this point, even if there is
+              PGs not clean at the specified epoch (0 disables it. dangerous,
+              use with care)
+:Type: Integer
+:Default: 0
+
+``mon osd cache size``
+
+:Description: The size of osdmaps cache, not to rely on underlying store's cache
+:Type: Integer
+:Default: 10
+
+
+``mon election timeout``
+
+:Description: On election proposer, maximum waiting time for all ACKs in seconds.
+:Type: Float
+:Default: ``5``
+
+
+``mon lease`` 
+
+:Description: The length (in seconds) of the lease on the monitor's versions.
+:Type: Float
+:Default: ``5``
+
+
+``mon lease renew interval factor``
+
+:Description: ``mon lease`` \* ``mon lease renew interval factor`` will be the
+              interval for the Leader to renew the other monitor's leases. The
+              factor should be less than ``1.0``.
+:Type: Float
+:Default: ``0.6``
+
+
+``mon lease ack timeout factor``
+
+:Description: The Leader will wait ``mon lease`` \* ``mon lease ack timeout factor``
+              for the Providers to acknowledge the lease extension.
+:Type: Float
+:Default: ``2.0``
+
+
+``mon accept timeout factor``
+
+:Description: The Leader will wait ``mon lease`` \* ``mon accept timeout factor``
+              for the Requester(s) to accept a Paxos update. It is also used
+              during the Paxos recovery phase for similar purposes.
+:Type: Float
+:Default: ``2.0``
+
+
+``mon min osdmap epochs`` 
+
+:Description: Minimum number of OSD map epochs to keep at all times.
+:Type: 32-bit Integer
+:Default: ``500``
+
+
+``mon max pgmap epochs`` 
+
+:Description: Maximum number of PG map epochs the monitor should keep.
+:Type: 32-bit Integer
+:Default: ``500``
+
+
+``mon max log epochs`` 
+
+:Description: Maximum number of Log epochs the monitor should keep.
+:Type: 32-bit Integer
+:Default: ``500``
+
+
+
+.. index:: Ceph Monitor; clock
+
+Clock
+-----
+
+Ceph daemons pass critical messages to each other, which must be processed
+before daemons reach a timeout threshold. If the clocks in Ceph monitors
+are not synchronized, it can lead to a number of anomalies. For example:
+
+- Daemons ignoring received messages (e.g., timestamps outdated)
+- Timeouts triggered too soon/late when a message wasn't received in time.
+
+See `Monitor Store Synchronization`_ for details.
+
+
+.. tip:: You SHOULD install NTP on your Ceph monitor hosts to 
+         ensure that the monitor cluster operates with synchronized clocks.
+
+Clock drift may still be noticeable with NTP even though the discrepancy is not
+yet harmful. Ceph's clock drift / clock skew warnings may get triggered even 
+though NTP maintains a reasonable level of synchronization. Increasing your 
+clock drift may be tolerable under such circumstances; however, a number of 
+factors such as workload, network latency, configuring overrides to default 
+timeouts and the `Monitor Store Synchronization`_ settings may influence 
+the level of acceptable clock drift without compromising Paxos guarantees.
+
+Ceph provides the following tunable options to allow you to find 
+acceptable values.
+
+
+``clock offset``
+
+:Description: How much to offset the system clock. See ``Clock.cc`` for details.
+:Type: Double
+:Default: ``0``
+
+
+.. deprecated:: 0.58
+
+``mon tick interval`` 
+
+:Description: A monitor's tick interval in seconds. 
+:Type: 32-bit Integer
+:Default: ``5`` 
+
+
+``mon clock drift allowed`` 
+
+:Description: The clock drift in seconds allowed between monitors.
+:Type: Float
+:Default: ``.050``
+
+
+``mon clock drift warn backoff`` 
+
+:Description: Exponential backoff for clock drift warnings
+:Type: Float
+:Default: ``5``
+
+
+``mon timecheck interval``
+
+:Description: The time check interval (clock drift check) in seconds 
+              for the Leader.
+
+:Type: Float
+:Default: ``300.0``
+
+
+``mon timecheck skew interval``
+
+:Description: The time check interval (clock drift check) in seconds when in
+              presence of a skew in seconds for the Leader.
+:Type: Float
+:Default: ``30.0``
+
+
+Client
+------
+
+``mon client hunt interval``
+
+:Description: The client will try a new monitor every ``N`` seconds until it
+              establishes a connection.
+              
+:Type: Double
+:Default: ``3.0``
+
+
+``mon client ping interval``
+
+:Description: The client will ping the monitor every ``N`` seconds.
+:Type: Double
+:Default: ``10.0``
+
+
+``mon client max log entries per message``
+
+:Description: The maximum number of log entries a monitor will generate 
+              per client message.
+
+:Type: Integer
+:Default: ``1000``
+
+
+``mon client bytes``
+
+:Description: The amount of client message data allowed in memory (in bytes).
+:Type: 64-bit Integer Unsigned
+:Default: ``100ul << 20``
+
+
+Pool settings
+=============
+Since version v0.94 there is support for pool flags which allow or disallow changes to be made to pools.
+
+Monitors can also disallow removal of pools if configured that way.
+
+``mon allow pool delete``
+
+:Description: If the monitors should allow pools to be removed. Regardless of what the pool flags say.
+:Type: Boolean
+:Default: ``false``
+
+``osd pool default flag hashpspool``
+
+:Description: Set the hashpspool flag on new pools
+:Type: Boolean
+:Default: ``true``
+
+``osd pool default flag nodelete``
+
+:Description: Set the nodelete flag on new pools. Prevents allow pool removal with this flag in any way.
+:Type: Boolean
+:Default: ``false``
+
+``osd pool default flag nopgchange``
+
+:Description: Set the nopgchange flag on new pools. Does not allow the number of PGs to be changed for a pool.
+:Type: Boolean
+:Default: ``false``
+
+``osd pool default flag nosizechange``
+
+:Description: Set the nosizechange flag on new pools. Does not allow the size to be changed of pool.
+:Type: Boolean
+:Default: ``false``
+
+For more information about the pool flags see `Pool values`_.
+
+Miscellaneous
+=============
+
+
+``mon max osd``
+
+:Description: The maximum number of OSDs allowed in the cluster.
+:Type: 32-bit Integer
+:Default: ``10000``
+
+``mon globalid prealloc`` 
+
+:Description: The number of global IDs to pre-allocate for clients and daemons in the cluster.
+:Type: 32-bit Integer
+:Default: ``100``
+
+``mon subscribe interval`` 
+
+:Description: The refresh interval (in seconds) for subscriptions. The 
+              subscription mechanism enables obtaining the cluster maps 
+              and log information.
+
+:Type: Double
+:Default: ``300`` 
+
+
+``mon stat smooth intervals``
+
+:Description: Ceph will smooth statistics over the last ``N`` PG maps.
+:Type: Integer
+:Default: ``2``
+
+
+``mon probe timeout`` 
+
+:Description: Number of seconds the monitor will wait to find peers before bootstrapping.
+:Type: Double
+:Default: ``2.0``
+
+
+``mon daemon bytes``
+
+:Description: The message memory cap for metadata server and OSD messages (in bytes).
+:Type: 64-bit Integer Unsigned
+:Default: ``400ul << 20``
+
+
+``mon max log entries per event``
+
+:Description: The maximum number of log entries per event. 
+:Type: Integer
+:Default: ``4096``
+
+
+``mon osd prime pg temp``
+
+:Description: Enables or disable priming the PGMap with the previous OSDs when an out
+              OSD comes back into the cluster. With the ``true`` setting the clients
+              will continue to use the previous OSDs until the newly in OSDs as that
+              PG peered.
+:Type: Boolean
+:Default: ``true``
+
+
+``mon osd prime pg temp max time``
+
+:Description: How much time in seconds the monitor should spend trying to prime the
+              PGMap when an out OSD comes back into the cluster.
+:Type: Float
+:Default: ``0.5``
+
+
+``mon osd prime pg temp max time estimate``
+
+:Description: Maximum estimate of time spent on each PG before we prime all PGs
+              in parallel.
+:Type: Float
+:Default: ``0.25``
+
+
+``mon osd allow primary affinity``
+
+:Description: allow ``primary_affinity`` to be set in the osdmap.
+:Type: Boolean
+:Default: False
+
+
+``mon osd pool ec fast read``
+
+:Description: Whether turn on fast read on the pool or not. It will be used as
+              the default setting of newly created erasure pools if ``fast_read``
+              is not specified at create time.
+:Type: Boolean
+:Default: False
+
+
+``mon mds skip sanity``
+
+:Description: Skip safety assertions on FSMap (in case of bugs where we want to
+              continue anyway). Monitor terminates if the FSMap sanity check
+              fails, but we can disable it by enabling this option.
+:Type: Boolean
+:Default: False
+
+
+``mon max mdsmap epochs``
+
+:Description: The maximum amount of mdsmap epochs to trim during a single proposal.
+:Type: Integer
+:Default: 500
+
+
+``mon config key max entry size``
+
+:Description: The maximum size of config-key entry (in bytes)
+:Type: Integer
+:Default: 4096
+
+
+``mon scrub interval``
+
+:Description: How often (in seconds) the monitor scrub its store by comparing
+              the stored checksums with the computed ones of all the stored
+              keys.
+:Type: Integer
+:Default: 3600*24
+
+
+``mon scrub max keys``
+
+:Description: The maximum number of keys to scrub each time.
+:Type: Integer
+:Default: 100
+
+
+``mon compact on start``
+
+:Description: Compact the database used as Ceph Monitor store on
+              ``ceph-mon`` start. A manual compaction helps to shrink the
+              monitor database and improve the performance of it if the regular
+              compaction fails to work.
+:Type: Boolean
+:Default: False
+
+
+``mon compact on bootstrap``
+
+:Description: Compact the database used as Ceph Monitor store on
+              on bootstrap. Monitor starts probing each other for creating
+              a quorum after bootstrap. If it times out before joining the
+              quorum, it will start over and bootstrap itself again.
+:Type: Boolean
+:Default: False
+
+
+``mon compact on trim``
+
+:Description: Compact a certain prefix (including paxos) when we trim its old states.
+:Type: Boolean
+:Default: True
+
+
+``mon cpu threads``
+
+:Description: Number of threads for performing CPU intensive work on monitor.
+:Type: Boolean
+:Default: True
+
+
+``mon osd mapping pgs per chunk``
+
+:Description: We calculate the mapping from placement group to OSDs in chunks.
+              This option specifies the number of placement groups per chunk.
+:Type: Integer
+:Default: 4096
+
+
+``mon osd max split count``
+
+:Description: Largest number of PGs per "involved" OSD to let split create.
+              When we increase the ``pg_num`` of a pool, the placement groups
+              will be splitted on all OSDs serving that pool. We want to avoid
+              extreme multipliers on PG splits.
+:Type: Integer
+:Default: 300
+
+
+``mon session timeout``
+
+:Description: Monitor will terminate inactive sessions stay idle over this
+              time limit.
+:Type: Integer
+:Default: 300
+
+
+
+.. _Paxos: http://en.wikipedia.org/wiki/Paxos_(computer_science)
+.. _Monitor Keyrings: ../../../dev/mon-bootstrap#secret-keys
+.. _Ceph configuration file: ../ceph-conf/#monitors
+.. _Network Configuration Reference: ../network-config-ref
+.. _Monitor lookup through DNS: ../mon-lookup-dns
+.. _ACID: http://en.wikipedia.org/wiki/ACID
+.. _Adding/Removing a Monitor: ../../operations/add-or-rm-mons
+.. _Add/Remove a Monitor (ceph-deploy): ../../deployment/ceph-deploy-mon
+.. _Monitoring a Cluster: ../../operations/monitoring
+.. _Monitoring OSDs and PGs: ../../operations/monitoring-osd-pg
+.. _Bootstrapping a Monitor: ../../../dev/mon-bootstrap
+.. _Changing a Monitor's IP Address: ../../operations/add-or-rm-mons#changing-a-monitor-s-ip-address
+.. _Monitor/OSD Interaction: ../mon-osd-interaction
+.. _Scalability and High Availability: ../../../architecture#scalability-and-high-availability
+.. _Pool values: ../../operations/pools/#set-pool-values