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diff --git a/doc/rados/configuration/mon-config-ref.rst b/doc/rados/configuration/mon-config-ref.rst new file mode 100644 index 000000000..e0a12d093 --- /dev/null +++ b/doc/rados/configuration/mon-config-ref.rst @@ -0,0 +1,642 @@ +.. _monitor-config-reference: + +========================== + 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**. The monitor complement usually remains fairly +consistent, but you can add, remove or replace a monitor in a cluster. See +`Adding/Removing a Monitor`_ for details. + + +.. index:: Ceph Monitor; Paxos + +Background +========== + +Ceph Monitors maintain a "master copy" of the :term:`Cluster Map`. + +The :term:`Cluster Map` makes it possible for :term:`Ceph client`\s to +determine the location of all Ceph Monitors, Ceph OSD Daemons, and Ceph +Metadata Servers. Clients do this by connecting to one Ceph Monitor and +retrieving a current cluster map. Ceph clients must connect to a Ceph Monitor +before they can read from or write to Ceph OSD Daemons or Ceph Metadata +Servers. A Ceph client that has a current copy of the cluster map and the CRUSH +algorithm can compute the location of any RADOS object within the cluster. This +makes it possible for Ceph clients to talk directly to Ceph OSD Daemons. Direct +communication between clients and Ceph OSD Daemons improves upon traditional +storage architectures that required clients to communicate with a central +component. See `Scalability and High Availability`_ for more on this subject. + +The Ceph Monitor's primary function is to maintain a master copy of the cluster +map. Monitors also provide authentication and logging services. All changes in +the monitor services are written by the Ceph Monitor to a single Paxos +instance, and Paxos writes the changes to a key/value store. This provides +strong consistency. Ceph Monitors are able to query the most recent version of +the cluster map during sync operations, and they use the key/value store's +snapshots and iterators (using RocksDB) 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 |*---------------------+ + \-------------/ + +.. 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.). + +.. confval:: mon_force_quorum_join + +.. 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 were to discover each other through the Ceph configuration file +instead of through the monmap, additional risks would be introduced because +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 help +bootstrap the Ceph Monitors by generating a monitor map for you (e.g., +``cephadm``, 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., ``cephadm`` 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 + ``cephadm`` 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 network address for each monitor. You can configure +these under ``[mon]`` or under the entry for a specific monitor. + +.. code-block:: ini + + [global] + mon_host = 10.0.0.2,10.0.0.3,10.0.0.4 + +.. 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 addresses of +monitors. However, if you decide to change the monitor's IP address, you +must follow a specific procedure. See :ref:`Changing a Monitor's IP address` for +details. + +Monitors can also be found by clients by 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. + +.. confval:: fsid + +.. 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 + + +.. confval:: mon_initial_members + +.. 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 uses +``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 plain files. This +approach allows users to inspect monitor data with common tools like ``ls`` +and ``cat``. However, this approach didn'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. + + +.. confval:: mon_data +.. confval:: mon_data_size_warn +.. confval:: mon_data_avail_warn +.. confval:: mon_data_avail_crit +.. confval:: mon_warn_on_crush_straw_calc_version_zero +.. confval:: mon_warn_on_legacy_crush_tunables +.. confval:: mon_crush_min_required_version +.. confval:: mon_warn_on_osd_down_out_interval_zero +.. confval:: mon_warn_on_slow_ping_ratio +.. confval:: mon_warn_on_slow_ping_time +.. confval:: mon_warn_on_pool_no_redundancy +.. confval:: mon_cache_target_full_warn_ratio +.. confval:: mon_health_to_clog +.. confval:: mon_health_to_clog_tick_interval +.. confval:: mon_health_to_clog_interval + +.. index:: Ceph Storage Cluster; capacity planning, Ceph Monitor; capacity planning + +.. _storage-capacity: + +Storage Capacity +---------------- + +When a Ceph Storage Cluster gets close to its maximum capacity +(see``mon_osd_full ratio``), Ceph prevents you from writing to or reading from OSDs +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 an +OSD from the Ceph Storage Cluster, watching the cluster rebalance, then removing +another OSD, and another, until at least one OSD eventually reaches the full +ratio and the cluster 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 OSDs +immediately. Cluster operation continues in the ``active+degraded`` state, but this +is not ideal for normal operation and should be addressed promptly. + +The following diagram depicts a simplistic Ceph Storage Cluster containing 33 +Ceph Nodes with one OSD per host, each OSD 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. + +The following settings only apply on cluster creation and are then stored in +the OSDMap. To clarify, in normal operation the values that are used by OSDs +are those found in the OSDMap, not those in the configuration file or central +config store. + +.. 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 threshold percentage of device space utilized before an OSD is + considered ``full``. + +:Type: Float +:Default: ``0.95`` + + +``mon_osd_backfillfull_ratio`` + +:Description: The threshold percentage of device space utilized before an OSD is + considered too ``full`` to backfill. + +:Type: Float +:Default: ``0.90`` + + +``mon_osd_nearfull_ratio`` + +:Description: The threshold percentage of device space used before an OSD is + considered ``nearfull``. + +:Type: Float +:Default: ``0.85`` + + +.. tip:: If some OSDs are nearfull, but others have plenty of capacity, you + may have an inaccurate CRUSH weight set for the nearfull OSDs. + +.. tip:: These settings only apply during cluster creation. Afterwards they need + to be changed in the OSDMap using ``ceph osd set-nearfull-ratio`` and + ``ceph osd set-full-ratio`` + +.. 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 performs trimming across the cluster. +Trimming requires that the placement groups are ``active+clean``. + + +.. confval:: mon_sync_timeout +.. confval:: mon_sync_max_payload_size +.. confval:: paxos_max_join_drift +.. confval:: paxos_stash_full_interval +.. confval:: paxos_propose_interval +.. confval:: paxos_min +.. confval:: paxos_min_wait +.. confval:: paxos_trim_min +.. confval:: paxos_trim_max +.. confval:: paxos_service_trim_min +.. confval:: paxos_service_trim_max +.. confval:: paxos_service_trim_max_multiplier +.. confval:: mon_mds_force_trim_to +.. confval:: mon_osd_force_trim_to +.. confval:: mon_osd_cache_size +.. confval:: mon_election_timeout +.. confval:: mon_lease +.. confval:: mon_lease_renew_interval_factor +.. confval:: mon_lease_ack_timeout_factor +.. confval:: mon_accept_timeout_factor +.. confval:: mon_min_osdmap_epochs +.. confval:: mon_max_log_epochs + + +.. index:: Ceph Monitor; clock + +.. _mon-config-ref-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 must configure NTP or PTP daemons on your Ceph monitor hosts to + ensure that the monitor cluster operates with synchronized clocks. + It can be advantageous to have monitor hosts sync with each other + as well as with multiple quality upstream time sources. + +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. + +.. confval:: mon_tick_interval +.. confval:: mon_clock_drift_allowed +.. confval:: mon_clock_drift_warn_backoff +.. confval:: mon_timecheck_interval +.. confval:: mon_timecheck_skew_interval + +Client +------ + +.. confval:: mon_client_hunt_interval +.. confval:: mon_client_ping_interval +.. confval:: mon_client_max_log_entries_per_message +.. confval:: mon_client_bytes + +.. _pool-settings: + +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 appropriately configured. The inconvenience of this guardrail +is far outweighed by the number of accidental pool (and thus data) deletions it prevents. + +.. confval:: mon_allow_pool_delete +.. confval:: osd_pool_default_ec_fast_read +.. confval:: osd_pool_default_flag_hashpspool +.. confval:: osd_pool_default_flag_nodelete +.. confval:: osd_pool_default_flag_nopgchange +.. confval:: osd_pool_default_flag_nosizechange + +For more information about the pool flags see :ref:`Pool values <setpoolvalues>`. + +Miscellaneous +============= + +.. confval:: mon_max_osd +.. confval:: mon_globalid_prealloc +.. confval:: mon_subscribe_interval +.. confval:: mon_stat_smooth_intervals +.. confval:: mon_probe_timeout +.. confval:: mon_daemon_bytes +.. confval:: mon_max_log_entries_per_event +.. confval:: mon_osd_prime_pg_temp +.. confval:: mon_osd_prime_pg_temp_max_time +.. confval:: mon_osd_prime_pg_temp_max_estimate +.. confval:: mon_mds_skip_sanity +.. confval:: mon_max_mdsmap_epochs +.. confval:: mon_config_key_max_entry_size +.. confval:: mon_scrub_interval +.. confval:: mon_scrub_max_keys +.. confval:: mon_compact_on_start +.. confval:: mon_compact_on_bootstrap +.. confval:: mon_compact_on_trim +.. confval:: mon_cpu_threads +.. confval:: mon_osd_mapping_pgs_per_chunk +.. confval:: mon_session_timeout +.. confval:: mon_osd_cache_size_min +.. confval:: mon_memory_target +.. confval:: mon_memory_autotune + +.. _Paxos: https://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: https://en.wikipedia.org/wiki/ACID +.. _Adding/Removing a Monitor: ../../operations/add-or-rm-mons +.. _Monitoring a Cluster: ../../operations/monitoring +.. _Monitoring OSDs and PGs: ../../operations/monitoring-osd-pg +.. _Bootstrapping a Monitor: ../../../dev/mon-bootstrap +.. _Monitor/OSD Interaction: ../mon-osd-interaction +.. _Scalability and High Availability: ../../../architecture#scalability-and-high-availability |