hadoop/hadoop-hdds/common/src/main/resources/ozone-default.xml

<?xml version="1.0" encoding="UTF-8"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
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<!-- Do not modify this file directly.  Instead, copy entries that you -->
<!-- wish to modify from this file into ozone-site.xml and change them -->
<!-- there.  If ozone-site.xml does not already exist, create it.      -->

<!--Tags supported are OZONE, CBLOCK, MANAGEMENT, SECURITY, PERFORMANCE,   -->
<!--DEBUG, CLIENT, SERVER, OM, SCM, CRITICAL, RATIS, CONTAINER, REQUIRED, -->
<!--REST, STORAGE, PIPELINE, STANDALONE                                    -->

<configuration>

  <!--Container Settings used by Datanode-->
  <property>
    <name>ozone.container.cache.size</name>
    <value>1024</value>
    <tag>PERFORMANCE, CONTAINER, STORAGE</tag>
    <description>The open container is cached on the data node side. We maintain
      an LRU
      cache for caching the recently used containers. This setting controls the
      size of that cache.
    </description>
  </property>
  <property>
    <name>dfs.container.ipc</name>
    <value>9859</value>
    <tag>OZONE, CONTAINER, MANAGEMENT</tag>
    <description>The ipc port number of container.</description>
  </property>
  <property>
    <name>dfs.container.ipc.random.port</name>
    <value>false</value>
    <tag>OZONE, DEBUG, CONTAINER</tag>
    <description>Allocates a random free port for ozone container. This is used
      only while
      running unit tests.
    </description>
  </property>
  <property>
    <name>dfs.container.ratis.datanode.storage.dir</name>
    <value/>
    <tag>OZONE, CONTAINER, STORAGE, MANAGEMENT, RATIS</tag>
    <description>This directory is used for storing Ratis metadata like logs. If
      this is
      not set then default metadata dirs is used. A warning will be logged if
      this not set. Ideally, this should be mapped to a fast disk like an SSD.
    </description>
  </property>
  <property>
    <name>hdds.datanode.dir</name>
    <value/>
    <tag>OZONE, CONTAINER, STORAGE, MANAGEMENT</tag>
    <description>Determines where on the local filesystem HDDS data will be
      stored. Defaults to dfs.datanode.data.dir if not specified.
      The directories should be tagged with corresponding storage types
      ([SSD]/[DISK]/[ARCHIVE]/[RAM_DISK]) for storage policies. The default
      storage type will be DISK if the directory does not have a storage type
      tagged explicitly.
    </description>
  </property>
  <property>
    <name>dfs.container.ratis.enabled</name>
    <value>false</value>
    <tag>OZONE, MANAGEMENT, PIPELINE, RATIS</tag>
    <description>Ozone supports different kinds of replication pipelines. Ratis
      is one of
      the replication pipeline supported by ozone.
    </description>
  </property>
  <property>
    <name>dfs.container.grpc.enabled</name>
    <value>false</value>
    <tag>OZONE, MANAGEMENT, PIPELINE, RATIS</tag>
    <description>Ozone supports different kinds of replication pipelines
      protocols. grpc is one of the replication pipeline protocol supported by
      ozone.
    </description>
  </property>
  <property>
    <name>dfs.container.ratis.ipc</name>
    <value>9858</value>
    <tag>OZONE, CONTAINER, PIPELINE, RATIS, MANAGEMENT</tag>
    <description>The ipc port number of container.</description>
  </property>
  <property>
    <name>dfs.container.ratis.ipc.random.port</name>
    <value>false</value>
    <tag>OZONE,DEBUG</tag>
    <description>Allocates a random free port for ozone ratis port for the
      container. This
      is used only while running unit tests.
    </description>
  </property>
  <property>
    <name>dfs.container.ratis.rpc.type</name>
    <value>GRPC</value>
    <tag>OZONE, RATIS, MANAGEMENT</tag>
    <description>Ratis supports different kinds of transports like netty, GRPC,
      Hadoop RPC
      etc. This picks one of those for this cluster.
    </description>
  </property>
  <property>
    <name>dfs.container.ratis.num.write.chunk.threads</name>
    <value>60</value>
    <tag>OZONE, RATIS, PERFORMANCE</tag>
    <description>Maximum number of threads in the thread pool that Ratis
      will use for writing chunks (60 by default).
    </description>
  </property>
  <property>
    <name>dfs.container.ratis.segment.size</name>
    <value>1073741824</value>
    <tag>OZONE, RATIS, PERFORMANCE</tag>
    <description>The size of the raft segment used by Apache Ratis on datanodes.
      (1 GB by default)
    </description>
  </property>
  <property>
    <name>dfs.container.ratis.segment.preallocated.size</name>
    <value>134217728</value>
    <tag>OZONE, RATIS, PERFORMANCE</tag>
    <description>The size of the buffer which is preallocated for raft segment
      used by Apache Ratis on datanodes.(128 MB by default)
    </description>
  </property>
  <property>
    <name>dfs.ratis.client.request.timeout.duration</name>
    <value>3s</value>
    <tag>OZONE, RATIS, MANAGEMENT</tag>
    <description>The timeout duration for ratis client request.</description>
  </property>
  <property>
    <name>dfs.ratis.server.request.timeout.duration</name>
    <value>3s</value>
    <tag>OZONE, RATIS, MANAGEMENT</tag>
    <description>The timeout duration for ratis server request.</description>
  </property>
  <property>
    <name>ozone.container.report.interval</name>
    <value>60000ms</value>
    <tag>OZONE, CONTAINER, MANAGEMENT</tag>
    <description>Time interval of the datanode to send container report. Each
      datanode periodically send container report upon receive
      sendContainerReport from SCM. Unit could be defined with
      postfix (ns,ms,s,m,h,d)</description>
  </property>
  <!--Ozone Settings-->
  <property>
    <name>ozone.administrators</name>
    <value/>
    <tag>OZONE, SECURITY</tag>
    <description>Ozone administrator users delimited by the comma.
      If not set, only the user who launches an ozone service will be the admin
      user. This property must be set if ozone services are started by different
      users. Otherwise, the RPC layer will reject calls from other servers which
      are started by users not in the list.
    </description>
  </property>
  <property>
    <name>ozone.block.deleting.container.limit.per.interval</name>
    <value>10</value>
    <tag>OZONE, PERFORMANCE, SCM</tag>
    <description>A maximum number of containers to be scanned by block deleting
      service per
      time interval. The block deleting service spawns a thread to handle block
      deletions in a container. This property is used to throttle the number of
      threads spawned for block deletions.
    </description>
  </property>
  <property>
    <name>ozone.block.deleting.limit.per.task</name>
    <value>1000</value>
    <tag>OZONE, PERFORMANCE, SCM</tag>
    <description>A maximum number of blocks to be deleted by block deleting
      service per
      time interval. This property is used to throttle the actual number of
      block deletions on a data node per container.
    </description>
  </property>
  <property>
    <name>ozone.block.deleting.service.interval</name>
    <value>1m</value>
    <tag>OZONE, PERFORMANCE, SCM</tag>
    <description>Time interval of the block deleting service.
      The block deleting service runs on each datanode periodically and
      deletes blocks queued for deletion. Unit could be defined with
      postfix (ns,ms,s,m,h,d)
    </description>
  </property>
  <property>
    <name>ozone.block.deleting.service.timeout</name>
    <value>300000ms</value>
    <tag>OZONE, PERFORMANCE, SCM</tag>
    <description>A timeout value of block deletion service. If this is set
      greater than 0,
      the service will stop waiting for the block deleting completion after this
      time. If timeout happens to a large proportion of block deletion, this
      needs to be increased with ozone.block.deleting.limit.per.task. This
      setting supports multiple time unit suffixes as described in
      dfs.heartbeat.interval. If no suffix is specified, then milliseconds is
      assumed.
    </description>
  </property>
  <property>
    <name>ozone.client.connection.timeout</name>
    <value>5000ms</value>
    <tag>OZONE, PERFORMANCE, CLIENT</tag>
    <description>Connection timeout for Ozone client in milliseconds.
    </description>
  </property>
  <property>
    <name>ozone.client.protocol</name>
    <value>org.apache.hadoop.ozone.client.rpc.RpcClient</value>
    <tag>OZONE, CLIENT, MANAGEMENT</tag>
    <description>Protocol class to be used by the client to connect to ozone
      cluster.
      The build-in implementation includes:
      org.apache.hadoop.ozone.client.rpc.RpcClient for RPC
      org.apache.hadoop.ozone.client.rest.RestClient for REST
      The default is the RpClient. Please do not change this unless you have a
      very good understanding of what you are doing.
    </description>
  </property>
  <property>
    <name>ozone.client.socket.timeout</name>
    <value>5000ms</value>
    <tag>OZONE, CLIENT</tag>
    <description>Socket timeout for Ozone client. Unit could be defined with
      postfix (ns,ms,s,m,h,d)</description>
  </property>
  <property>
    <name>ozone.enabled</name>
    <value>false</value>
    <tag>OZONE, REQUIRED</tag>
    <description>
      Status of the Ozone Object Storage service is enabled.
      Set to true to enable Ozone.
      Set to false to disable Ozone.
      Unless this value is set to true, Ozone services will not be started in
      the cluster.

      Please note: By default ozone is disabled on a hadoop cluster.
    </description>
  </property>
  <property>
    <name>ozone.handler.type</name>
    <value>distributed</value>
    <tag>OZONE, REST</tag>
    <description>
      Tells ozone which storage handler to use. The possible values are:
      distributed - The Ozone distributed storage handler, which speaks to
      OM/SCM on the backend and provides REST services to clients.
      local - Local Storage handler strictly for testing - To be removed.
    </description>
  </property>
  <property>
    <name>ozone.key.deleting.limit.per.task</name>
    <value>1000</value>
    <tag>OM, PERFORMANCE</tag>
    <description>
      A maximum number of keys to be scanned by key deleting service
      per time interval in OM. Those keys are sent to delete metadata and
      generate transactions in SCM for next async deletion between SCM
      and DataNode.
    </description>
  </property>
  <property>
    <name>ozone.om.address</name>
    <value/>
    <tag>OM, REQUIRED</tag>
    <description>
      The address of the Ozone OM service. This allows clients to discover
      the address of the OM.
    </description>
  </property>
  <property>
    <name>ozone.om.group.rights</name>
    <value>READ_WRITE</value>
    <tag>OM, SECURITY</tag>
    <description>
      Default group permissions in Ozone OM.
    </description>
  </property>
  <property>
    <name>ozone.om.handler.count.key</name>
    <value>20</value>
    <tag>OM, PERFORMANCE</tag>
    <description>
      The number of RPC handler threads for OM service endpoints.
    </description>
  </property>
  <property>
    <name>ozone.om.http-address</name>
    <value>0.0.0.0:9874</value>
    <tag>OM, MANAGEMENT</tag>
    <description>
      The address and the base port where the OM web UI will listen on.

      If the port is 0, then the server will start on a free port. However, it
      is best to specify a well-known port, so it is easy to connect and see
      the OM management UI.
    </description>
  </property>
  <property>
    <name>ozone.om.http-bind-host</name>
    <value>0.0.0.0</value>
    <tag>OM, MANAGEMENT</tag>
    <description>
      The actual address the OM web server will bind to. If this optional
      the address is set, it overrides only the hostname portion of
      ozone.om.http-address.
    </description>
  </property>
  <property>
    <name>ozone.om.http.enabled</name>
    <value>true</value>
    <tag>OM, MANAGEMENT</tag>
    <description>
      Property to enable or disable OM web user interface.
    </description>
  </property>
  <property>
    <name>ozone.om.https-address</name>
    <value>0.0.0.0:9875</value>
    <tag>OM, MANAGEMENT, SECURITY</tag>
    <description>
      The address and the base port where the OM web UI will listen
      on using HTTPS.
      If the port is 0 then the server will start on a free port.
    </description>
  </property>
  <property>
    <name>ozone.om.https-bind-host</name>
    <value>0.0.0.0</value>
    <tag>OM, MANAGEMENT, SECURITY</tag>
    <description>
      The actual address the OM web server will bind to using HTTPS.
      If this optional address is set, it overrides only the hostname portion of
      ozone.om.http-address.
    </description>
  </property>
  <property>
    <name>ozone.om.keytab.file</name>
    <value/>
    <tag>OM, SECURITY</tag>
    <description>
      The keytab file for Kerberos authentication in OM.
    </description>
  </property>
  <property>
    <name>ozone.om.db.cache.size.mb</name>
    <value>128</value>
    <tag>OM, PERFORMANCE</tag>
    <description>
      The size of OM DB cache in MB that used for caching files.
      This value is set to an abnormally low value in the default configuration.
      That is to make unit testing easy. Generally, this value should be set to
      something like 16GB or more, if you intend to use Ozone at scale.

      A large value for this key allows a proportionally larger amount of OM
      metadata to be cached in memory. This makes OM operations faster.
    </description>
  </property>
  <property>
    <name>ozone.om.user.max.volume</name>
    <value>1024</value>
    <tag>OM, MANAGEMENT</tag>
    <description>
      The maximum number of volumes a user can have on a cluster.Increasing or
      decreasing this number has no real impact on ozone cluster. This is
      defined only for operational purposes. Only an administrator can create a
      volume, once a volume is created there are no restrictions on the number
      of buckets or keys inside each bucket a user can create.
    </description>
  </property>
  <property>
    <name>ozone.om.user.rights</name>
    <value>READ_WRITE</value>
    <tag>OM, SECURITY</tag>
    <description>
      Default user permissions used in OM.
    </description>
  </property>
  <property>
    <name>ozone.localstorage.root</name>
    <value>${hadoop.tmp.dir}/ozone</value>
    <tag>OZONE, DEBUG</tag>
    <description>
      This is used only for testing purposes. This value is used by the local
      storage handler to simulate a REST backend. This is useful only when
      debugging the REST front end independent of OM and SCM. To be removed.
    </description>
  </property>
  <property>
    <name>ozone.metadata.dirs</name>
    <value/>
    <tag>OZONE, OM, SCM, CONTAINER, REQUIRED, STORAGE</tag>
    <description>
      Ozone metadata is shared among OM, which acts as the namespace
      manager for ozone, SCM which acts as the block manager and data nodes
      which maintain the name of the key(Key Name and BlockIDs). This
      replicated and distributed metadata store is maintained under the
      directory pointed by this key. Since metadata can be I/O intensive, at
      least on OM and SCM we recommend having SSDs. If you have the luxury
      of mapping this path to SSDs on all machines in the cluster, that will
      be excellent.

      If Ratis metadata directories are not specified, Ratis server will emit a
      warning and use this path for storing its metadata too.
    </description>
  </property>
  <property>
    <name>ozone.metastore.impl</name>
    <value>RocksDB</value>
    <tag>OZONE, OM, SCM, CONTAINER, STORAGE</tag>
    <description>
      Ozone metadata store implementation. Ozone metadata are well
      distributed to multiple services such as ozoneManager, scm. They are stored in
      some local key-value databases. This property determines which database
      library to use. Supported value is either LevelDB or RocksDB.
    </description>
  </property>

  <property>
    <name>ozone.metastore.rocksdb.statistics</name>
    <value>ALL</value>
    <tag>OZONE, OM, SCM, STORAGE, PERFORMANCE</tag>
    <description>
      The statistics level of the rocksdb store. If you use any value from
      org.rocksdb.StatsLevel (eg. ALL or EXCEPT_DETAILED_TIMERS), the rocksdb
      statistics will be exposed over JMX bean with the choosed setting. Set
      it to OFF to not initialize rocksdb statistics at all. Please note that
      collection of statistics could have 5-10% performance penalty.
      Check the rocksdb documentation for more details.
    </description>
  </property>

  <property>
    <name>ozone.scm.block.client.address</name>
    <value/>
    <tag>OZONE, SCM</tag>
    <description>The address of the Ozone SCM block client service. If not
      defined value of ozone.scm.client.address is used.
    </description>
  </property>
  <property>
    <name>ozone.scm.block.client.bind.host</name>
    <value>0.0.0.0</value>
    <tag>OZONE, SCM</tag>
    <description>
      The hostname or IP address used by the SCM block client
      endpoint to bind.
    </description>
  </property>
  <property>
    <name>ozone.scm.block.client.port</name>
    <value>9863</value>
    <tag>OZONE, SCM</tag>
    <description>
      The port number of the Ozone SCM block client service.
    </description>
  </property>
  <property>
    <name>ozone.scm.block.deletion.max.retry</name>
    <value>4096</value>
    <tag>OZONE, SCM</tag>
    <description>
      SCM wraps up many blocks in a deletion transaction and sends that to data
      node for physical deletion periodically. This property determines how many
      times SCM is going to retry sending a deletion operation to the data node.
    </description>
  </property>
  <property>
    <name>ozone.scm.block.size.in.mb</name>
    <value>256</value>
    <tag>OZONE, SCM</tag>
    <description>
      The default size of a scm block in bytes. This is maps to the default
      Ozone block size.
    </description>
  </property>
  <property>
    <name>ozone.scm.chunk.size</name>
    <value>16777216</value>
    <tag>OZONE, SCM, CONTAINER, PERFORMANCE</tag>
    <description>
      The chunk size for reading/writing chunk operations in bytes.

      The chunk size defaults to 8MB. If the value configured is more than the
      maximum size (16MB), it will be reset to the maximum size. This maps to
      the network packet sizes and file write operations in the client to
      datanode protocol.
    </description>
  </property>
  <property>
    <name>ozone.scm.client.address</name>
    <value/>
    <tag>OZONE, SCM, REQUIRED</tag>
    <description>
      The address of the Ozone SCM client service. This is a required setting.

      It is a string in the host:port format. The port number is optional
      and defaults to 9860.
    </description>
  </property>
  <property>
    <name>ozone.scm.client.bind.host</name>
    <value>0.0.0.0</value>
    <tag>OZONE, SCM, MANAGEMENT</tag>
    <description>The hostname or IP address used by the SCM client endpoint to
      bind.
      This setting is used by the SCM only and never used by clients.

      The setting can be useful in multi-homed setups to restrict the
      availability of the SCM client service to a specific interface.

      The default is appropriate for most clusters.
    </description>
  </property>
  <property>
    <name>ozone.scm.client.port</name>
    <value>9860</value>
    <tag>OZONE, SCM, MANAGEMENT</tag>
    <description>The port number of the Ozone SCM client service.</description>
  </property>
  <property>
    <name>ozone.scm.container.deletion-choosing.policy</name>
    <value>
      org.apache.hadoop.ozone.container.common.impl.TopNOrderedContainerDeletionChoosingPolicy
    </value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The policy used for choosing desire containers for block deletion.
      Datanode selects some containers to process block deletion
      in a certain interval defined by ozone.block.deleting.service.interval.
      The number of containers to process in each interval is defined
      by ozone.block.deleting.container.limit.per.interval. This property is
      used to configure the policy applied while selecting containers.
      There are two policies supporting now:
      RandomContainerDeletionChoosingPolicy and
      TopNOrderedContainerDeletionChoosingPolicy.
      org.apache.hadoop.ozone.container.common.impl.RandomContainerDeletionChoosingPolicy
      implements a simply random policy that to return a random list of
      containers.
      org.apache.hadoop.ozone.container.common.impl.TopNOrderedContainerDeletionChoosingPolicy
      implements a policy that choosing top count number of containers in a
      pending-deletion-blocks's num
      based descending order.
    </description>
  </property>
  <property>
    <name>ozone.scm.container.placement.impl</name>
    <value>
      org.apache.hadoop.hdds.scm.container.placement.algorithms.SCMContainerPlacementRandom
    </value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>Placement policy class for containers.
      Defaults to SCMContainerPlacementRandom.class
    </description>
  </property>
  <property>
    <name>ozone.scm.container.provision_batch_size</name>
    <value>20</value>
    <tag>OZONE, PERFORMANCE</tag>
    <description>Pre-provision specified number of containers for block
      allocation.
    </description>
  </property>
  <property>
    <name>ozone.scm.container.size.gb</name>
    <value>5</value>
    <tag>OZONE, PERFORMANCE, MANAGEMENT</tag>
    <description>
      Default container size used by Ozone. This value is specified
      in GB.
      There are two considerations while picking this number. The speed at which
      a container can be replicated, determined by the network speed and the
      metadata that each container generates. So selecting a large number
      creates less SCM metadata, but recovery time will be more. 5GB is a number
      that maps to quick replication times in gigabit networks, but still
      balances the amount of metadata.
    </description>
  </property>
  <property>
    <name>ozone.scm.datanode.address</name>
    <value/>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The address of the Ozone SCM service used for internal
      communication between the DataNodes and the SCM.

      It is a string in the host:port format. The port number is optional
      and defaults to 9861.

      This setting is optional. If unspecified then the hostname portion
      is picked from the ozone.scm.client.address setting and the
      default service port of 9861 is chosen.
    </description>
  </property>
  <property>
    <name>ozone.scm.datanode.bind.host</name>
    <value/>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The hostname or IP address used by the SCM service endpoint to
      bind.
    </description>
  </property>
  <property>
    <name>ozone.scm.datanode.id</name>
    <value/>
    <tag>OZONE, MANAGEMENT</tag>
    <description>The path that datanodes will use to store the datanode ID.
      If this value is not set, then datanode ID is created under the
      metadata directory.
    </description>
  </property>
  <property>
    <name>ozone.scm.datanode.port</name>
    <value>9861</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The port number of the Ozone SCM service.
    </description>
  </property>
  <property>
    <name>ozone.scm.db.cache.size.mb</name>
    <value>128</value>
    <tag>OZONE, PERFORMANCE</tag>
    <description>SCM keeps track of the Containers in the cluster. This DB holds
      the container metadata. This value is set to a small value to make the
      unit
      testing runs smooth. In production, we recommend a value of 16GB or
      higher. This allows SCM to avoid disk I/O's while looking up the container
      location.
    </description>
  </property>
  <property>
    <name>ozone.scm.dead.node.interval</name>
    <value>10m</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The interval between heartbeats before a node is tagged as dead.
    </description>
  </property>
  <property>
    <name>ozone.scm.handler.count.key</name>
    <value>10</value>
    <tag>OZONE, MANAGEMENT, PERFORMANCE</tag>
    <description>
      The number of RPC handler threads for each SCM service
      endpoint.

      The default is appropriate for small clusters (tens of nodes).

      Set a value that is appropriate for the cluster size. Generally, HDFS
      recommends RPC handler count is set to 20 * log2(Cluster Size) with an
      upper limit of 200. However, SCM will not have the same amount of
      traffic as Namenode, so a value much smaller than that will work well too.
    </description>
  </property>
  <property>
    <name>ozone.scm.heartbeat.interval</name>
    <value>30s</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The heartbeat interval from a data node to SCM. Yes,
      it is not three but 30, since most data nodes will heart beating via Ratis
      heartbeats. If a client is not able to talk to a data node, it will notify
      OM/SCM eventually. So a 30 second HB seems to work. This assumes that
      replication strategy used is Ratis if not, this value should be set to
      something smaller like 3 seconds.
    </description>
  </property>
  <property>
    <name>ozone.scm.heartbeat.log.warn.interval.count</name>
    <value>10</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      Defines how frequently we will log the missing of a heartbeat to SCM.
      For example in the default case, we will write a warning message for each
      ten consecutive heartbeats that we miss to SCM. This helps in reducing
      clutter in a data node log, but trade off is that logs will have less of
      this statement.
    </description>
  </property>
  <property>
    <name>ozone.scm.heartbeat.rpc-timeout</name>
    <value>1000</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      Timeout value for the RPC from Datanode to SCM in milliseconds.
    </description>
  </property>
  <property>
    <name>ozone.scm.heartbeat.thread.interval</name>
    <value>3s</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      When a heartbeat from the data node arrives on SCM, It is queued for
      processing with the time stamp of when the heartbeat arrived. There is a
      heartbeat processing thread inside SCM that runs at a specified interval.
      This value controls how frequently this thread is run.

      There are some assumptions build into SCM such as this value should allow
      the heartbeat processing thread to run at least three times more
      frequently than heartbeats and at least five times more than stale node
      detection time. If you specify a wrong value, SCM will gracefully refuse
      to run. For more info look at the node manager tests in SCM.

      In short, you don't need to change this.
    </description>
  </property>
  <property>
    <name>ozone.scm.http-address</name>
    <value>0.0.0.0:9876</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The address and the base port where the SCM web ui will listen on.

      If the port is 0 then the server will start on a free port.
    </description>
  </property>
  <property>
    <name>ozone.scm.http-bind-host</name>
    <value>0.0.0.0</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The actual address the SCM web server will bind to. If this
      optional address is set, it overrides only the hostname portion of
      ozone.scm.http-address.
    </description>
  </property>
  <property>
    <name>ozone.scm.http.enabled</name>
    <value>true</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      Property to enable or disable SCM web ui.
    </description>
  </property>
  <property>
    <name>ozone.scm.https-address</name>
    <value>0.0.0.0:9877</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The address and the base port where the SCM web UI will listen
      on using HTTPS.

      If the port is 0 then the server will start on a free port.
    </description>
  </property>
  <property>
    <name>ozone.scm.https-bind-host</name>
    <value>0.0.0.0</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The actual address the SCM web server will bind to using HTTPS.
      If this optional address is set, it overrides only the hostname portion of
      ozone.scm.http-address.
    </description>
  </property>
  <property>
    <name>ozone.scm.keytab.file</name>
    <value/>
    <tag>OZONE, SECURITY</tag>
    <description>
      The keytab file for Kerberos authentication in SCM.
    </description>
  </property>
  <property>
    <name>ozone.scm.names</name>
    <value/>
    <tag>OZONE</tag>
    <description>
      The value of this property is a set of DNS | DNS:PORT | IP
      Address | IP:PORT. Written as a comma separated string. e.g. scm1,
      scm2:8020, 7.7.7.7:7777.
      This property allows datanodes to discover where SCM is, so that
      datanodes can send heartbeat to SCM.
    </description>
  </property>
  <property>
    <name>ozone.scm.stale.node.interval</name>
    <value>90s</value>
    <tag>OZONE, MANAGEMENT</tag>
    <description>
      The interval for stale node flagging. Please
      see ozone.scm.heartbeat.thread.interval before changing this value.
    </description>
  </property>
  <property>
    <name>ozone.trace.enabled</name>
    <value>false</value>
    <tag>OZONE, DEBUG</tag>
    <description>
      Setting this flag to true dumps the HTTP request/ response in
      the logs. Very useful when debugging REST protocol.
    </description>
  </property>
  <property>
    <name>ozone.web.authentication.kerberos.principal</name>
    <value/>
    <tag>OZONE, SECURITY</tag>
    <description>
      The server principal used by the SCM and OM for web UI SPNEGO
      authentication when Kerberos security is enabled. This is typically set to
      HTTP/_HOST@REALM.TLD The SPNEGO server principal begins with the prefix
      HTTP/ by convention.

      If the value is '*', the web server will attempt to login with
      every principal specified in the keytab file.
    </description>
  </property>

  <!--Client Settings-->
  <property>
    <name>scm.container.client.idle.threshold</name>
    <value>10s</value>
    <tag>OZONE, PERFORMANCE</tag>
    <description>
      In the standalone pipelines, the SCM clients use netty to
      communicate with the container. It also uses connection pooling to
      reduce client side overheads. This allows a connection to stay idle for
      a while before the connection is closed.
    </description>
  </property>
  <property>
    <name>scm.container.client.max.size</name>
    <value>256</value>
    <tag>OZONE, PERFORMANCE</tag>
    <description>
      Controls the maximum number of connections that we cached via
      clientconnection pooling. If the number of connection
      exceed this count then the oldest idle connection is evicted.
    </description>
  </property>

  <property>
    <name>scm.container.client.max.outstanding.requests</name>
    <value>100</value>
    <tag>OZONE, PERFORMANCE</tag>
    <description>
      Controls the maximum number of outstanding async requests that can be
      handled by the Standalone as well as Ratis client.
    </description>
  </property>

  <property>
    <name>ozone.scm.container.creation.lease.timeout</name>
    <value>60s</value>
    <tag>OZONE, SCM</tag>
    <description>
      Container creation timeout in milliseconds to be used by SCM. When
      BEGIN_CREATE event happens the container is moved from ALLOCATED to
      CREATING state, SCM will now wait for the configured amount of time
      to get COMPLETE_CREATE event if it doesn't receive it will move the
      container to DELETING.
    </description>
  </property>

  <property>
    <name>ozone.key.preallocation.maxsize</name>
    <value>134217728</value>
    <tag>OZONE, OM, PERFORMANCE</tag>
    <description>
      When a new key write request is sent to OM, if a size is requested, at most
      128MB of size is allocated at request time. If client needs more space for the
      write, separate block allocation requests will be made.
    </description>
  </property>

  <property>
    <name>ozone.client.list.cache</name>
    <value>1000</value>
    <tag>OZONE, PERFORMANCE</tag>
    <description>
      Configuration property to configure the cache size of client list calls.
    </description>
  </property>

  <property>
    <name>ozone.replication</name>
    <value>3</value>
    <tag>OZONE, CLIENT</tag>
    <description>
      Default replication value. The actual number of replications can be
      specified when writing the key. The default is used if replication
      is not specified. Supported values: 1 and 3.
    </description>
  </property>

  <property>
    <name>ozone.replication.type</name>
    <value>RATIS</value>
    <tag>OZONE, CLIENT</tag>
    <description>
      Default replication type to be used while writing key into ozone. The
      value can be specified when writing the key, default is used when
      nothing is specified. Supported values: RATIS, STAND_ALONE and CHAINED.
    </description>
  </property>
  <property>
    <name>ozone.scm.container.close.threshold</name>
    <value>0.9f</value>
    <tag>OZONE, SCM</tag>
    <description>
      This determines the threshold to be used for closing a container.
      When the container used percentage reaches this threshold,
      the container will be closed. Value should be a positive, non-zero
      percentage in float notation (X.Yf), with 1.0f meaning 100%.
    </description>
  </property>
  <property>
    <name>ozone.rest.client.http.connection.max</name>
    <value>100</value>
    <tag>OZONE, CLIENT</tag>
    <description>
      This defines the overall connection limit for the connection pool used in
      RestClient.
    </description>
  </property>
  <property>
    <name>ozone.rest.client.http.connection.per-route.max</name>
    <value>20</value>
    <tag>OZONE, CLIENT</tag>
    <description>
      This defines the connection limit per one HTTP route/host. Total max
      connection is limited by ozone.rest.client.http.connection.max property.
    </description>
  </property>

  <property>
    <name>ozone.open.key.cleanup.service.interval.seconds</name>
    <value>86400</value>
    <tag>OZONE, OM, PERFORMANCE</tag>
    <description>
      A background job periodically checks open key entries and delete the expired ones. This entry controls the
      interval of this cleanup check.
    </description>
  </property>

  <property>
    <name>ozone.open.key.expire.threshold</name>
    <value>86400</value>
    <tag>OZONE, OM, PERFORMANCE</tag>
    <description>
      Controls how long an open key operation is considered active. Specifically, if a key
      has been open longer than the value of this config entry, that open key is considered as
      expired (e.g. due to client crash). Default to 24 hours.
    </description>
  </property>

  <property>
    <name>hadoop.tags.custom</name>
    <value>OZONE,MANAGEMENT,SECURITY,PERFORMANCE,DEBUG,CLIENT,SERVER,OM,SCM,CRITICAL,RATIS,CONTAINER,REQUIRED,REST,STORAGE,PIPELINE,STANDALONE</value>
  </property>

  <property>
    <name>ozone.tags.system</name>
    <value>OZONE,MANAGEMENT,SECURITY,PERFORMANCE,DEBUG,CLIENT,SERVER,OM,SCM,CRITICAL,RATIS,CONTAINER,REQUIRED,REST,STORAGE,PIPELINE,STANDALONE</value>
  </property>


  <property>
    <name>hdds.rest.rest-csrf.enabled</name>
    <value>false</value>
    <description>
      If true, then enables Object Store REST server protection against
      cross-site request forgery (CSRF).
    </description>
  </property>

  <property>
    <name>hdds.rest.http-address</name>
    <value>0.0.0.0:9880</value>
    <description>The http address of Object Store REST server inside the
      datanode.</description>
  </property>


  <property>
    <name>hdds.rest.netty.high.watermark</name>
    <value>65535</value>
    <description>
      High watermark configuration to Netty for Object Store REST server.
    </description>
  </property>

  <property>
    <name>hdds.rest.netty.low.watermark</name>
    <value>32768</value>
    <description>
      Low watermark configuration to Netty for Object Store REST server.
    </description>
  </property>

  <property>
    <name>hdds.datanode.plugins</name>
    <value>org.apache.hadoop.ozone.web.OzoneHddsDatanodeService</value>
    <description>
      Comma-separated list of HDDS datanode plug-ins to be activated when
      HDDS service starts as part of datanode.
    </description>
  </property>
  <property>
    <name>hdds.datanode.storage.utilization.warning.threshold</name>
    <value>0.75</value>
    <tag>OZONE, SCM, MANAGEMENT</tag>
    <description>
      If a datanode overall storage utilization exceeds more than this
      value, a warning will be logged while processing the nodeReport in SCM.
    </description>
  </property>

  <property>
    <name>hdds.datanode.storage.utilization.critical.threshold</name>
    <value>0.95</value>
    <tag>OZONE, SCM, MANAGEMENT</tag>
    <description>
      If a datanode overall storage utilization exceeds more than this
      value, the datanode will be marked out of space.
    </description>
  </property>

  <property>
    <name>hdds.write.lock.reporting.threshold.ms</name>
    <value>5000</value>
    <tag>OZONE, DATANODE, MANAGEMENT</tag>
    <description>
      When a write lock is held for a long time, this will be logged as the
      lock is released. This sets how long the lock must be held for logging
      to occur.
    </description>
  </property>

  <property>
    <name>hdds.lock.suppress.warning.interval.ms</name>
    <value>10000</value>
    <tag>OZONE, DATANODE, MANAGEMENT</tag>
    <description>
      Instrumentation reporting long critical sections will suppress
      consecutive warnings within this interval.
    </description>
  </property>

  <property>
    <name>hdds.command.status.report.interval</name>
    <value>30s</value>
    <tag>OZONE, DATANODE, MANAGEMENT</tag>
    <description>Time interval of the datanode to send status of commands
      executed since last report. Unit could be defined with
      postfix (ns,ms,s,m,h,d)</description>
  </property>

</configuration>