hbase-default.xml

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<!--
OVERVIEW

The important configs. are listed near the top.  You should change
at least the setting for hbase.tmp.dir.  Other settings will change
dependent on whether you are running hbase in standalone mode or
distributed.  See the hbase reference guide for requirements and
guidance making configuration.

This file does not contain all possible configurations.  The file would be
much larger if it carried everything. The absent configurations will only be
found through source code reading.  The idea is that such configurations are
exotic and only those who would go to the trouble of reading a particular
section in the code would be knowledgeable or invested enough in ever wanting
to alter such configurations, so we do not list them here.  Listing all
possible configurations would overwhelm and obscure the important.
-->

<configuration>
  <!--Configs you will likely change are listed here at the top of the file.
  -->
  <property >
    <name>hbase.tmp.dir</name>
    <value>${java.io.tmpdir}/hbase-${user.name}</value>
    <description>Temporary directory on the local filesystem.
    Change this setting to point to a location more permanent
    than '/tmp', the usual resolve for java.io.tmpdir, as the
    '/tmp' directory is cleared on machine restart.</description>
  </property>
  <property >
    <name>hbase.rootdir</name>
    <value>${hbase.tmp.dir}/hbase</value>
    <description>The directory shared by region servers and into
    which HBase persists.  The URL should be 'fully-qualified'
    to include the filesystem scheme.  For example, to specify the
    HDFS directory '/hbase' where the HDFS instance's namenode is
    running at namenode.example.org on port 9000, set this value to:
    hdfs://namenode.example.org:9000/hbase.  By default, we write
    to whatever ${hbase.tmp.dir} is set too -- usually /tmp --
    so change this configuration or else all data will be lost on
    machine restart.</description>
  </property>
  <property >
    <name>hbase.cluster.distributed</name>
    <value>false</value>
    <description>The mode the cluster will be in. Possible values are
      false for standalone mode and true for distributed mode.  If
      false, startup will run all HBase and ZooKeeper daemons together
      in the one JVM.</description>
  </property>
  <property>
    <name>hbase.zookeeper.quorum</name>
    <value>localhost</value>
    <description>Comma separated list of servers in the ZooKeeper ensemble
    (This config. should have been named hbase.zookeeper.ensemble).
    For example, "host1.mydomain.com,host2.mydomain.com,host3.mydomain.com".
    By default this is set to localhost for local and pseudo-distributed modes
    of operation. For a fully-distributed setup, this should be set to a full
    list of ZooKeeper ensemble servers. If HBASE_MANAGES_ZK is set in hbase-env.sh
    this is the list of servers which hbase will start/stop ZooKeeper on as
    part of cluster start/stop.  Client-side, we will take this list of
    ensemble members and put it together with the hbase.zookeeper.property.clientPort
    config. and pass it into zookeeper constructor as the connectString
    parameter.</description>
  </property>
  <!--The above are the important configurations for getting hbase up
    and running -->

  <property>
    <name>zookeeper.recovery.retry.maxsleeptime</name>
    <value>60000</value>
    <description>Max sleep time before retry zookeeper operations in milliseconds,
    a max time is needed here so that sleep time won't grow unboundedly
    </description>
  </property>
  <property>
    <name>hbase.local.dir</name>
    <value>${hbase.tmp.dir}/local/</value>
    <description>Directory on the local filesystem to be used
    as a local storage.</description>
  </property>

  <!--Master configurations-->
  <property >
    <name>hbase.master.port</name>
    <value>16000</value>
    <description>The port the HBase Master should bind to.</description>
  </property>
  <property>
    <name>hbase.master.info.port</name>
    <value>16010</value>
    <description>The port for the HBase Master web UI.
    Set to -1 if you do not want a UI instance run.</description>
  </property>
  <property>
    <name>hbase.master.info.bindAddress</name>
    <value>0.0.0.0</value>
    <description>The bind address for the HBase Master web UI
    </description>
  </property>
  <property>
    <name>hbase.master.logcleaner.plugins</name>
    <value>org.apache.hadoop.hbase.master.cleaner.TimeToLiveLogCleaner,org.apache.hadoop.hbase.master.cleaner.TimeToLiveProcedureWALCleaner</value>
    <description>A comma-separated list of BaseLogCleanerDelegate invoked by
    the LogsCleaner service. These WAL cleaners are called in order,
    so put the cleaner that prunes the most files in front. To
    implement your own BaseLogCleanerDelegate, just put it in HBase's classpath
    and add the fully qualified class name here. Always add the above
    default log cleaners in the list.</description>
  </property>
  <property>
    <name>hbase.master.logcleaner.ttl</name>
    <value>600000</value>
    <description>How long a WAL remain in the archive ({hbase.rootdir}/oldWALs) directory,
    after which it will be cleaned by a Master thread. The value is in milliseconds.</description>
  </property>
  <property>
    <name>hbase.master.procedurewalcleaner.ttl</name>
    <value>604800000</value>
    <description>How long a Procedure WAL will remain in the
    archive directory, after which it will be cleaned
    by a Master thread. The value is in milliseconds.</description>
  </property>
  <property>
    <name>hbase.master.hfilecleaner.plugins</name>
    <value>org.apache.hadoop.hbase.master.cleaner.TimeToLiveHFileCleaner</value>
    <description>A comma-separated list of BaseHFileCleanerDelegate invoked by
    the HFileCleaner service. These HFiles cleaners are called in order,
    so put the cleaner that prunes the most files in front. To
    implement your own BaseHFileCleanerDelegate, just put it in HBase's classpath
    and add the fully qualified class name here. Always add the above
    default log cleaners in the list as they will be overwritten in
    hbase-site.xml.</description>
  </property>
  <property>
    <name>hbase.master.infoserver.redirect</name>
    <value>true</value>
    <description>Whether or not the Master listens to the Master web
      UI port (hbase.master.info.port) and redirects requests to the web
      UI server shared by the Master and RegionServer. Config. makes
      sense when Master is serving Regions (not the default).</description>
  </property>
  <property>
    <name>hbase.master.fileSplitTimeout</name>
    <value>600000</value>
    <description>Splitting a region, how long to wait on the file-splitting
      step before aborting the attempt. Default: 600000. This setting used
      to be known as hbase.regionserver.fileSplitTimeout in hbase-1.x.
      Split is now run master-side hence the rename (If a
      'hbase.master.fileSplitTimeout' setting found, will use it to
      prime the current 'hbase.master.fileSplitTimeout'
      Configuration.</description>
  </property>

  <!--RegionServer configurations-->
  <property>
    <name>hbase.regionserver.port</name>
    <value>16020</value>
    <description>The port the HBase RegionServer binds to.</description>
  </property>
  <property>
    <name>hbase.regionserver.info.port</name>
    <value>16030</value>
    <description>The port for the HBase RegionServer web UI
    Set to -1 if you do not want the RegionServer UI to run.</description>
  </property>
  <property>
    <name>hbase.regionserver.info.bindAddress</name>
    <value>0.0.0.0</value>
    <description>The address for the HBase RegionServer web UI</description>
  </property>
  <property>
    <name>hbase.regionserver.info.port.auto</name>
    <value>false</value>
    <description>Whether or not the Master or RegionServer
    UI should search for a port to bind to. Enables automatic port
    search if hbase.regionserver.info.port is already in use.
    Useful for testing, turned off by default.</description>
  </property>
  <property>
    <name>hbase.regionserver.handler.count</name>
    <value>30</value>
    <description>Count of RPC Listener instances spun up on RegionServers.
      Same property is used by the Master for count of master handlers.
      Too many handlers can be counter-productive. Make it a multiple of
      CPU count. If mostly read-only, handlers count close to cpu count
      does well. Start with twice the CPU count and tune from there.</description>
  </property>
  <property>
    <name>hbase.ipc.server.callqueue.handler.factor</name>
    <value>0.1</value>
    <description>Factor to determine the number of call queues.
      A value of 0 means a single queue shared between all the handlers.
      A value of 1 means that each handler has its own queue.</description>
  </property>
  <property>
    <name>hbase.ipc.server.callqueue.read.ratio</name>
    <value>0</value>
    <description>Split the call queues into read and write queues.
      The specified interval (which should be between 0.0 and 1.0)
      will be multiplied by the number of call queues.
      A value of 0 indicate to not split the call queues, meaning that both read and write
      requests will be pushed to the same set of queues.
      A value lower than 0.5 means that there will be less read queues than write queues.
      A value of 0.5 means there will be the same number of read and write queues.
      A value greater than 0.5 means that there will be more read queues than write queues.
      A value of 1.0 means that all the queues except one are used to dispatch read requests.

      Example: Given the total number of call queues being 10
      a read.ratio of 0 means that: the 10 queues will contain both read/write requests.
      a read.ratio of 0.3 means that: 3 queues will contain only read requests
      and 7 queues will contain only write requests.
      a read.ratio of 0.5 means that: 5 queues will contain only read requests
      and 5 queues will contain only write requests.
      a read.ratio of 0.8 means that: 8 queues will contain only read requests
      and 2 queues will contain only write requests.
      a read.ratio of 1 means that: 9 queues will contain only read requests
      and 1 queues will contain only write requests.
    </description>
  </property>
  <property>
    <name>hbase.ipc.server.callqueue.scan.ratio</name>
    <value>0</value>
    <description>Given the number of read call queues, calculated from the total number
      of call queues multiplied by the callqueue.read.ratio, the scan.ratio property
      will split the read call queues into small-read and long-read queues.
      A value lower than 0.5 means that there will be less long-read queues than short-read queues.
      A value of 0.5 means that there will be the same number of short-read and long-read queues.
      A value greater than 0.5 means that there will be more long-read queues than short-read queues
      A value of 0 or 1 indicate to use the same set of queues for gets and scans.

      Example: Given the total number of read call queues being 8
      a scan.ratio of 0 or 1 means that: 8 queues will contain both long and short read requests.
      a scan.ratio of 0.3 means that: 2 queues will contain only long-read requests
      and 6 queues will contain only short-read requests.
      a scan.ratio of 0.5 means that: 4 queues will contain only long-read requests
      and 4 queues will contain only short-read requests.
      a scan.ratio of 0.8 means that: 6 queues will contain only long-read requests
      and 2 queues will contain only short-read requests.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.msginterval</name>
    <value>3000</value>
    <description>Interval between messages from the RegionServer to Master
    in milliseconds.</description>
  </property>
  <property>
    <name>hbase.regionserver.logroll.period</name>
    <value>3600000</value>
    <description>Period at which we will roll the commit log regardless
    of how many edits it has.</description>
  </property>
  <property>
    <name>hbase.regionserver.logroll.errors.tolerated</name>
    <value>2</value>
    <description>The number of consecutive WAL close errors we will allow
    before triggering a server abort.  A setting of 0 will cause the
    region server to abort if closing the current WAL writer fails during
    log rolling.  Even a small value (2 or 3) will allow a region server
    to ride over transient HDFS errors.</description>
  </property>
  <property>
    <name>hbase.regionserver.hlog.reader.impl</name>
    <value>org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader</value>
    <description>The WAL file reader implementation.</description>
  </property>
  <property>
    <name>hbase.regionserver.hlog.writer.impl</name>
    <value>org.apache.hadoop.hbase.regionserver.wal.ProtobufLogWriter</value>
    <description>The WAL file writer implementation.</description>
  </property>
  <property>
    <name>hbase.regionserver.global.memstore.size</name>
    <value></value>
    <description>Maximum size of all memstores in a region server before new
      updates are blocked and flushes are forced. Defaults to 40% of heap (0.4).
      Updates are blocked and flushes are forced until size of all memstores
      in a region server hits hbase.regionserver.global.memstore.size.lower.limit.
      The default value in this configuration has been intentionally left empty in order to
      honor the old hbase.regionserver.global.memstore.upperLimit property if present.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.global.memstore.size.lower.limit</name>
    <value></value>
    <description>Maximum size of all memstores in a region server before flushes
      are forced. Defaults to 95% of hbase.regionserver.global.memstore.size
      (0.95). A 100% value for this value causes the minimum possible flushing
      to occur when updates are blocked due to memstore limiting. The default
      value in this configuration has been intentionally left empty in order to
      honor the old hbase.regionserver.global.memstore.lowerLimit property if
      present.
    </description>
  </property>
  <property>
    <name>hbase.systemtables.compacting.memstore.type</name>
    <value>NONE</value>
    <description>Determines the type of memstore to be used for system tables like
      META, namespace tables etc. By default NONE is the type and hence we use the
      default memstore for all the system tables. If we need to use compacting
      memstore for system tables then set this property to BASIC/EAGER
    </description>
  </property>
  <property>
    <name>hbase.regionserver.optionalcacheflushinterval</name>
    <value>3600000</value>
    <description>
    Maximum amount of time an edit lives in memory before being automatically flushed.
    Default 1 hour. Set it to 0 to disable automatic flushing.
  </description>
  </property>
  <property>
    <name>hbase.regionserver.dns.interface</name>
    <value>default</value>
    <description>The name of the Network Interface from which a region server
      should report its IP address.</description>
  </property>
  <property>
    <name>hbase.regionserver.dns.nameserver</name>
    <value>default</value>
    <description>The host name or IP address of the name server (DNS)
      which a region server should use to determine the host name used by the
      master for communication and display purposes.</description>
  </property>
  <property>
    <name>hbase.regionserver.region.split.policy</name>
    <value>org.apache.hadoop.hbase.regionserver.SteppingSplitPolicy</value>
    <description>
      A split policy determines when a region should be split. The various
      other split policies that are available currently are BusyRegionSplitPolicy,
      ConstantSizeRegionSplitPolicy, DisabledRegionSplitPolicy,
      DelimitedKeyPrefixRegionSplitPolicy, KeyPrefixRegionSplitPolicy, and
      SteppingSplitPolicy. DisabledRegionSplitPolicy blocks manual region splitting.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.regionSplitLimit</name>
    <value>1000</value>
    <description>
      Limit for the number of regions after which no more region splitting
      should take place. This is not hard limit for the number of regions
      but acts as a guideline for the regionserver to stop splitting after
      a certain limit. Default is set to 1000.
    </description>
  </property>

  <!--ZooKeeper configuration-->
  <property>
    <name>zookeeper.session.timeout</name>
    <value>90000</value>
    <description>ZooKeeper session timeout in milliseconds. It is used in two different ways.
      First, this value is used in the ZK client that HBase uses to connect to the ensemble.
      It is also used by HBase when it starts a ZK server and it is passed as the 'maxSessionTimeout'.
      See http://hadoop.apache.org/zookeeper/docs/current/zookeeperProgrammers.html#ch_zkSessions.
      For example, if an HBase region server connects to a ZK ensemble that's also managed
      by HBase, then the session timeout will be the one specified by this configuration.
      But, a region server that connects to an ensemble managed with a different configuration
      will be subjected that ensemble's maxSessionTimeout. So, even though HBase might propose
      using 90 seconds, the ensemble can have a max timeout lower than this and it will take
      precedence. The current default that ZK ships with is 40 seconds, which is lower than
      HBase's.
    </description>
  </property>
  <property>
    <name>zookeeper.znode.parent</name>
    <value>/hbase</value>
    <description>Root ZNode for HBase in ZooKeeper. All of HBase's ZooKeeper
      files that are configured with a relative path will go under this node.
      By default, all of HBase's ZooKeeper file paths are configured with a
      relative path, so they will all go under this directory unless changed.
    </description>
  </property>
  <property>
    <name>zookeeper.znode.acl.parent</name>
    <value>acl</value>
    <description>Root ZNode for access control lists.</description>
  </property>
  <property>
    <name>hbase.zookeeper.dns.interface</name>
    <value>default</value>
    <description>The name of the Network Interface from which a ZooKeeper server
      should report its IP address.</description>
  </property>
  <property>
    <name>hbase.zookeeper.dns.nameserver</name>
    <value>default</value>
    <description>The host name or IP address of the name server (DNS)
      which a ZooKeeper server should use to determine the host name used by the
      master for communication and display purposes.</description>
  </property>
  <!--
  The following three properties are used together to create the list of
  host:peer_port:leader_port quorum servers for ZooKeeper.
  -->
  <property>
    <name>hbase.zookeeper.peerport</name>
    <value>2888</value>
    <description>Port used by ZooKeeper peers to talk to each other.
    See http://hadoop.apache.org/zookeeper/docs/r3.1.1/zookeeperStarted.html#sc_RunningReplicatedZooKeeper
    for more information.</description>
  </property>
  <property>
    <name>hbase.zookeeper.leaderport</name>
    <value>3888</value>
    <description>Port used by ZooKeeper for leader election.
    See http://hadoop.apache.org/zookeeper/docs/r3.1.1/zookeeperStarted.html#sc_RunningReplicatedZooKeeper
    for more information.</description>
  </property>
  <!-- End of properties used to generate ZooKeeper host:port quorum list. -->

  <!--
  Beginning of properties that are directly mapped from ZooKeeper's zoo.cfg.
  All properties with an "hbase.zookeeper.property." prefix are converted for
  ZooKeeper's configuration. Hence, if you want to add an option from zoo.cfg,
  e.g.  "initLimit=10" you would append the following to your configuration:
    <property>
      <name>hbase.zookeeper.property.initLimit</name>
      <value>10</value>
    </property>
  -->
  <property>
    <name>hbase.zookeeper.property.initLimit</name>
    <value>10</value>
    <description>Property from ZooKeeper's config zoo.cfg.
    The number of ticks that the initial synchronization phase can take.</description>
  </property>
  <property>
    <name>hbase.zookeeper.property.syncLimit</name>
    <value>5</value>
    <description>Property from ZooKeeper's config zoo.cfg.
    The number of ticks that can pass between sending a request and getting an
    acknowledgment.</description>
  </property>
  <property>
    <name>hbase.zookeeper.property.dataDir</name>
    <value>${hbase.tmp.dir}/zookeeper</value>
    <description>Property from ZooKeeper's config zoo.cfg.
    The directory where the snapshot is stored.</description>
  </property>
  <property>
    <name>hbase.zookeeper.property.clientPort</name>
    <value>2181</value>
    <description>Property from ZooKeeper's config zoo.cfg.
    The port at which the clients will connect.</description>
  </property>
  <property>
    <name>hbase.zookeeper.property.maxClientCnxns</name>
    <value>300</value>
    <description>Property from ZooKeeper's config zoo.cfg.
    Limit on number of concurrent connections (at the socket level) that a
    single client, identified by IP address, may make to a single member of
    the ZooKeeper ensemble. Set high to avoid zk connection issues running
    standalone and pseudo-distributed.</description>
  </property>
  <!-- End of properties that are directly mapped from ZooKeeper's zoo.cfg -->

  <!--Client configurations-->
  <property>
    <name>hbase.client.write.buffer</name>
    <value>2097152</value>
    <description>Default size of the BufferedMutator write buffer in bytes.
    A bigger buffer takes more memory -- on both the client and server
    side since server instantiates the passed write buffer to process
    it -- but a larger buffer size reduces the number of RPCs made.
    For an estimate of server-side memory-used, evaluate
    hbase.client.write.buffer * hbase.regionserver.handler.count</description>
  </property>
  <property>
    <name>hbase.client.pause</name>
    <value>100</value>
    <description>General client pause value.  Used mostly as value to wait
    before running a retry of a failed get, region lookup, etc.
    See hbase.client.retries.number for description of how we backoff from
    this initial pause amount and how this pause works w/ retries.</description>
  </property>
  <property>
    <name>hbase.client.pause.cqtbe</name>
    <value></value>
    <description>Whether or not to use a special client pause for
    CallQueueTooBigException (cqtbe). Set this property to a higher value
    than hbase.client.pause if you observe frequent CQTBE from the same
    RegionServer and the call queue there keeps full</description>
  </property>
  <property>
    <name>hbase.client.retries.number</name>
    <value>15</value>
    <description>Maximum retries.  Used as maximum for all retryable
    operations such as the getting of a cell's value, starting a row update,
    etc.  Retry interval is a rough function based on hbase.client.pause.  At
    first we retry at this interval but then with backoff, we pretty quickly reach
    retrying every ten seconds.  See HConstants#RETRY_BACKOFF for how the backup
    ramps up.  Change this setting and hbase.client.pause to suit your workload.</description>
  </property>
  <property>
    <name>hbase.client.max.total.tasks</name>
    <value>100</value>
    <description>The maximum number of concurrent mutation tasks a single HTable instance will
    send to the cluster.</description>
  </property>
  <property>
    <name>hbase.client.max.perserver.tasks</name>
    <value>2</value>
    <description>The maximum number of concurrent mutation tasks a single HTable instance will
    send to a single region server.</description>
  </property>
  <property>
    <name>hbase.client.max.perregion.tasks</name>
    <value>1</value>
    <description>The maximum number of concurrent mutation tasks the client will
    maintain to a single Region. That is, if there is already
    hbase.client.max.perregion.tasks writes in progress for this region, new puts
    won't be sent to this region until some writes finishes.</description>
  </property>
  <property>
    <name>hbase.client.perserver.requests.threshold</name>
    <value>2147483647</value>
    <description>The max number of concurrent pending requests for one server in all client threads
    (process level). Exceeding requests will be thrown ServerTooBusyException immediately to prevent
    user's threads being occupied and blocked by only one slow region server. If you use a fix
    number of threads to access HBase in a synchronous way, set this to a suitable value which is
    related to the number of threads will help you. See
    https://issues.apache.org/jira/browse/HBASE-16388 for details.</description>
  </property>
  <property>
    <name>hbase.client.scanner.caching</name>
    <value>2147483647</value>
    <description>Number of rows that we try to fetch when calling next
    on a scanner if it is not served from (local, client) memory. This configuration
    works together with hbase.client.scanner.max.result.size to try and use the
    network efficiently. The default value is Integer.MAX_VALUE by default so that
    the network will fill the chunk size defined by hbase.client.scanner.max.result.size
    rather than be limited by a particular number of rows since the size of rows varies
    table to table. If you know ahead of time that you will not require more than a certain
    number of rows from a scan, this configuration should be set to that row limit via
    Scan#setCaching. Higher caching values will enable faster scanners but will eat up more
    memory and some calls of next may take longer and longer times when the cache is empty.
    Do not set this value such that the time between invocations is greater than the scanner
    timeout; i.e. hbase.client.scanner.timeout.period</description>
  </property>
  <property>
    <name>hbase.client.keyvalue.maxsize</name>
    <value>10485760</value>
    <description>Specifies the combined maximum allowed size of a KeyValue
    instance. This is to set an upper boundary for a single entry saved in a
    storage file. Since they cannot be split it helps avoiding that a region
    cannot be split any further because the data is too large. It seems wise
    to set this to a fraction of the maximum region size. Setting it to zero
    or less disables the check.</description>
  </property>
  <property>
    <name>hbase.server.keyvalue.maxsize</name>
    <value>10485760</value>
    <description>Maximum allowed size of an individual cell, inclusive of value and all key
    components. A value of 0 or less disables the check.
    The default value is 10MB.
    This is a safety setting to protect the server from OOM situations.
    </description>
  </property>
  <property>
    <name>hbase.client.scanner.timeout.period</name>
    <value>60000</value>
    <description>Client scanner lease period in milliseconds.</description>
  </property>
  <property>
    <name>hbase.client.localityCheck.threadPoolSize</name>
    <value>2</value>
  </property>

  <!--Miscellaneous configuration-->
  <property>
    <name>hbase.bulkload.retries.number</name>
    <value>10</value>
    <description>Maximum retries.  This is maximum number of iterations
    to atomic bulk loads are attempted in the face of splitting operations
    0 means never give up.</description>
  </property>
  <property>
    <name>hbase.master.balancer.maxRitPercent</name>
    <value>1.0</value>
    <description>The max percent of regions in transition when balancing.
      The default value is 1.0. So there are no balancer throttling. If set this config to 0.01,
      It means that there are at most 1% regions in transition when balancing.
      Then the cluster's availability is at least 99% when balancing.</description>
  </property>
  <property>
    <name>hbase.balancer.period
    </name>
    <value>300000</value>
    <description>Period at which the region balancer runs in the Master.</description>
  </property>
  <property>
    <name>hbase.normalizer.period</name>
    <value>300000</value>
    <description>Period at which the region normalizer runs in the Master.</description>
  </property>
  <property>
    <name>hbase.normalizer.min.region.count</name>
    <value>3</value>
    <description>configure the minimum number of regions</description>
  </property>
  <property>
    <name>hbase.regions.slop</name>
    <value>0.001</value>
    <description>Rebalance if any regionserver has average + (average * slop) regions.
      The default value of this parameter is 0.001 in StochasticLoadBalancer (the default load balancer),
      while the default is 0.2 in other load balancers (i.e., SimpleLoadBalancer).</description>
  </property>
  <property>
    <name>hbase.server.thread.wakefrequency</name>
    <value>10000</value>
    <description>Time to sleep in between searches for work (in milliseconds).
    Used as sleep interval by service threads such as log roller.</description>
  </property>
  <property>
    <name>hbase.server.versionfile.writeattempts</name>
    <value>3</value>
    <description>
    How many times to retry attempting to write a version file
    before just aborting. Each attempt is separated by the
    hbase.server.thread.wakefrequency milliseconds.</description>
  </property>
  <property>
    <name>hbase.hregion.memstore.flush.size</name>
    <value>134217728</value>
    <description>
    Memstore will be flushed to disk if size of the memstore
    exceeds this number of bytes.  Value is checked by a thread that runs
    every hbase.server.thread.wakefrequency.</description>
  </property>
  <property>
    <name>hbase.hregion.percolumnfamilyflush.size.lower.bound.min</name>
    <value>16777216</value>
    <description>
    If FlushLargeStoresPolicy is used and there are multiple column families,
    then every time that we hit the total memstore limit, we find out all the
    column families whose memstores exceed a "lower bound" and only flush them
    while retaining the others in memory. The "lower bound" will be
    "hbase.hregion.memstore.flush.size / column_family_number" by default
    unless value of this property is larger than that. If none of the families
    have their memstore size more than lower bound, all the memstores will be
    flushed (just as usual).
    </description>
  </property>
  <property>
    <name>hbase.hregion.preclose.flush.size</name>
    <value>5242880</value>
    <description>
      If the memstores in a region are this size or larger when we go
      to close, run a "pre-flush" to clear out memstores before we put up
      the region closed flag and take the region offline.  On close,
      a flush is run under the close flag to empty memory.  During
      this time the region is offline and we are not taking on any writes.
      If the memstore content is large, this flush could take a long time to
      complete.  The preflush is meant to clean out the bulk of the memstore
      before putting up the close flag and taking the region offline so the
      flush that runs under the close flag has little to do.</description>
  </property>
  <property>
    <name>hbase.hregion.memstore.block.multiplier</name>
    <value>4</value>
    <description>
    Block updates if memstore has hbase.hregion.memstore.block.multiplier
    times hbase.hregion.memstore.flush.size bytes.  Useful preventing
    runaway memstore during spikes in update traffic.  Without an
    upper-bound, memstore fills such that when it flushes the
    resultant flush files take a long time to compact or split, or
    worse, we OOME.</description>
  </property>
  <property>
    <name>hbase.hregion.memstore.mslab.enabled</name>
    <value>true</value>
    <description>
      Enables the MemStore-Local Allocation Buffer,
      a feature which works to prevent heap fragmentation under
      heavy write loads. This can reduce the frequency of stop-the-world
      GC pauses on large heaps.</description>
  </property>
  <property>
    <name>hbase.hregion.max.filesize</name>
    <value>10737418240</value>
    <description>
    Maximum HFile size. If the sum of the sizes of a region's HFiles has grown to exceed this
    value, the region is split in two.</description>
  </property>
  <property>
    <name>hbase.hregion.majorcompaction</name>
    <value>604800000</value>
    <description>Time between major compactions, expressed in milliseconds. Set to 0 to disable
      time-based automatic major compactions. User-requested and size-based major compactions will
      still run. This value is multiplied by hbase.hregion.majorcompaction.jitter to cause
      compaction to start at a somewhat-random time during a given window of time. The default value
      is 7 days, expressed in milliseconds. If major compactions are causing disruption in your
      environment, you can configure them to run at off-peak times for your deployment, or disable
      time-based major compactions by setting this parameter to 0, and run major compactions in a
      cron job or by another external mechanism.</description>
  </property>
  <property>
    <name>hbase.hregion.majorcompaction.jitter</name>
    <value>0.50</value>
    <description>A multiplier applied to hbase.hregion.majorcompaction to cause compaction to occur
      a given amount of time either side of hbase.hregion.majorcompaction. The smaller the number,
      the closer the compactions will happen to the hbase.hregion.majorcompaction
      interval.</description>
  </property>
  <property>
    <name>hbase.hstore.compactionThreshold</name>
    <value>3</value>
    <description> If more than this number of StoreFiles exist in any one Store
      (one StoreFile is written per flush of MemStore), a compaction is run to rewrite all
      StoreFiles into a single StoreFile. Larger values delay compaction, but when compaction does
      occur, it takes longer to complete.</description>
  </property>
  <property>
    <name>hbase.hstore.flusher.count</name>
    <value>2</value>
    <description> The number of flush threads. With fewer threads, the MemStore flushes will be
      queued. With more threads, the flushes will be executed in parallel, increasing the load on
      HDFS, and potentially causing more compactions. </description>
  </property>
  <property>
    <name>hbase.hstore.blockingStoreFiles</name>
    <value>16</value>
    <description> If more than this number of StoreFiles exist in any one Store (one StoreFile
     is written per flush of MemStore), updates are blocked for this region until a compaction is
      completed, or until hbase.hstore.blockingWaitTime has been exceeded.</description>
  </property>
  <property>
    <name>hbase.hstore.blockingWaitTime</name>
    <value>90000</value>
    <description> The time for which a region will block updates after reaching the StoreFile limit
    defined by hbase.hstore.blockingStoreFiles. After this time has elapsed, the region will stop
    blocking updates even if a compaction has not been completed.</description>
  </property>
  <property>
    <name>hbase.hstore.compaction.min</name>
    <value>3</value>
    <description>The minimum number of StoreFiles which must be eligible for compaction before
      compaction can run. The goal of tuning hbase.hstore.compaction.min is to avoid ending up with
      too many tiny StoreFiles to compact. Setting this value to 2 would cause a minor compaction
      each time you have two StoreFiles in a Store, and this is probably not appropriate. If you
      set this value too high, all the other values will need to be adjusted accordingly. For most
      cases, the default value is appropriate. In previous versions of HBase, the parameter
      hbase.hstore.compaction.min was named hbase.hstore.compactionThreshold.</description>
  </property>
  <property>
    <name>hbase.hstore.compaction.max</name>
    <value>10</value>
    <description>The maximum number of StoreFiles which will be selected for a single minor
      compaction, regardless of the number of eligible StoreFiles. Effectively, the value of
      hbase.hstore.compaction.max controls the length of time it takes a single compaction to
      complete. Setting it larger means that more StoreFiles are included in a compaction. For most
      cases, the default value is appropriate.</description>
  </property>
  <property>
    <name>hbase.hstore.compaction.min.size</name>
    <value>134217728</value>
    <description>A StoreFile (or a selection of StoreFiles, when using ExploringCompactionPolicy)
      smaller than this size will always be eligible for minor compaction.
      HFiles this size or larger are evaluated by hbase.hstore.compaction.ratio to determine if
      they are eligible. Because this limit represents the "automatic include" limit for all
      StoreFiles smaller than this value, this value may need to be reduced in write-heavy
      environments where many StoreFiles in the 1-2 MB range are being flushed, because every
      StoreFile will be targeted for compaction and the resulting StoreFiles may still be under the
      minimum size and require further compaction. If this parameter is lowered, the ratio check is
      triggered more quickly. This addressed some issues seen in earlier versions of HBase but
      changing this parameter is no longer necessary in most situations. Default: 128 MB expressed
      in bytes.</description>
  </property>
    <property>
    <name>hbase.hstore.compaction.max.size</name>
    <value>9223372036854775807</value>
    <description>A StoreFile (or a selection of StoreFiles, when using ExploringCompactionPolicy)
      larger than this size will be excluded from compaction. The effect of
      raising hbase.hstore.compaction.max.size is fewer, larger StoreFiles that do not get
      compacted often. If you feel that compaction is happening too often without much benefit, you
      can try raising this value. Default: the value of LONG.MAX_VALUE, expressed in bytes.</description>
  </property>
  <property>
    <name>hbase.hstore.compaction.ratio</name>
    <value>1.2F</value>
    <description>For minor compaction, this ratio is used to determine whether a given StoreFile
      which is larger than hbase.hstore.compaction.min.size is eligible for compaction. Its
      effect is to limit compaction of large StoreFiles. The value of hbase.hstore.compaction.ratio
      is expressed as a floating-point decimal. A large ratio, such as 10, will produce a single
      giant StoreFile. Conversely, a low value, such as .25, will produce behavior similar to the
      BigTable compaction algorithm, producing four StoreFiles. A moderate value of between 1.0 and
      1.4 is recommended. When tuning this value, you are balancing write costs with read costs.
      Raising the value (to something like 1.4) will have more write costs, because you will
      compact larger StoreFiles. However, during reads, HBase will need to seek through fewer
      StoreFiles to accomplish the read. Consider this approach if you cannot take advantage of
      Bloom filters. Otherwise, you can lower this value to something like 1.0 to reduce the
      background cost of writes, and use Bloom filters to control the number of StoreFiles touched
      during reads. For most cases, the default value is appropriate.</description>
  </property>
  <property>
    <name>hbase.hstore.compaction.ratio.offpeak</name>
    <value>5.0F</value>
    <description>Allows you to set a different (by default, more aggressive) ratio for determining
      whether larger StoreFiles are included in compactions during off-peak hours. Works in the
      same way as hbase.hstore.compaction.ratio. Only applies if hbase.offpeak.start.hour and
      hbase.offpeak.end.hour are also enabled.</description>
  </property>
  <property>
    <name>hbase.hstore.time.to.purge.deletes</name>
    <value>0</value>
    <description>The amount of time to delay purging of delete markers with future timestamps. If
      unset, or set to 0, all delete markers, including those with future timestamps, are purged
      during the next major compaction. Otherwise, a delete marker is kept until the major compaction
      which occurs after the marker's timestamp plus the value of this setting, in milliseconds.
    </description>
  </property>
  <property>
    <name>hbase.offpeak.start.hour</name>
    <value>-1</value>
    <description>The start of off-peak hours, expressed as an integer between 0 and 23, inclusive.
      Set to -1 to disable off-peak.</description>
  </property>
  <property>
    <name>hbase.offpeak.end.hour</name>
    <value>-1</value>
    <description>The end of off-peak hours, expressed as an integer between 0 and 23, inclusive. Set
      to -1 to disable off-peak.</description>
  </property>
  <property>
    <name>hbase.regionserver.thread.compaction.throttle</name>
    <value>2684354560</value>
    <description>There are two different thread pools for compactions, one for large compactions and
      the other for small compactions. This helps to keep compaction of lean tables (such as
      hbase:meta) fast. If a compaction is larger than this threshold, it
      goes into the large compaction pool. In most cases, the default value is appropriate. Default:
      2 x hbase.hstore.compaction.max x hbase.hregion.memstore.flush.size (which defaults to 128MB).
      The value field assumes that the value of hbase.hregion.memstore.flush.size is unchanged from
      the default.</description>
  </property>
  <property>
    <name>hbase.regionserver.majorcompaction.pagecache.drop</name>
    <value>true</value>
    <description>Specifies whether to drop pages read/written into the system page cache by
      major compactions. Setting it to true helps prevent major compactions from
      polluting the page cache, which is almost always required, especially for clusters
      with low/moderate memory to storage ratio.</description>
  </property>
  <property>
    <name>hbase.regionserver.minorcompaction.pagecache.drop</name>
    <value>true</value>
    <description>Specifies whether to drop pages read/written into the system page cache by
      minor compactions. Setting it to true helps prevent minor compactions from
      polluting the page cache, which is most beneficial on clusters with low
      memory to storage ratio or very write heavy clusters. You may want to set it to
      false under moderate to low write workload when bulk of the reads are
      on the most recently written data.</description>
  </property>
  <property>
    <name>hbase.hstore.compaction.kv.max</name>
    <value>10</value>
    <description>The maximum number of KeyValues to read and then write in a batch when flushing or
      compacting. Set this lower if you have big KeyValues and problems with Out Of Memory
      Exceptions Set this higher if you have wide, small rows. </description>
  </property>
  <property>
    <name>hbase.storescanner.parallel.seek.enable</name>
    <value>false</value>
    <description>
      Enables StoreFileScanner parallel-seeking in StoreScanner,
      a feature which can reduce response latency under special conditions.</description>
  </property>
  <property>
    <name>hbase.storescanner.parallel.seek.threads</name>
    <value>10</value>
    <description>
      The default thread pool size if parallel-seeking feature enabled.</description>
  </property>
  <property>
    <name>hfile.block.cache.size</name>
    <value>0.4</value>
    <description>Percentage of maximum heap (-Xmx setting) to allocate to block cache
        used by a StoreFile. Default of 0.4 means allocate 40%.
        Set to 0 to disable but it's not recommended; you need at least
        enough cache to hold the storefile indices.</description>
  </property>
  <property>
      <name>hfile.block.index.cacheonwrite</name>
      <value>false</value>
      <description>This allows to put non-root multi-level index blocks into the block
          cache at the time the index is being written.</description>
  </property>
  <property>
      <name>hfile.index.block.max.size</name>
      <value>131072</value>
      <description>When the size of a leaf-level, intermediate-level, or root-level
          index block in a multi-level block index grows to this size, the
          block is written out and a new block is started.</description>
  </property>
    <property>
    <name>hbase.bucketcache.ioengine</name>
    <value></value>
    <description>Where to store the contents of the bucketcache. One of: offheap,
    file, files or mmap. If a file or files, set it to file(s):PATH_TO_FILE.
    mmap means the content will be in an mmaped file. Use mmap:PATH_TO_FILE.
    See http://hbase.apache.org/book.html#offheap.blockcache for more information.
    </description>
  </property>
  <property>
    <name>hbase.bucketcache.size</name>
    <value></value>
    <description>A float that EITHER represents a percentage of total heap memory
    size to give to the cache (if &lt; 1.0) OR, it is the total capacity in
    megabytes of BucketCache. Default: 0.0</description>
  </property>
  <property>
    <name>hbase.bucketcache.bucket.sizes</name>
    <value></value>
    <description>A comma-separated list of sizes for buckets for the bucketcache.
    Can be multiple sizes. List block sizes in order from smallest to largest.
    The sizes you use will depend on your data access patterns.
    Must be a multiple of 256 else you will run into
    'java.io.IOException: Invalid HFile block magic' when you go to read from cache.
    If you specify no values here, then you pick up the default bucketsizes set
    in code (See BucketAllocator#DEFAULT_BUCKET_SIZES).
  </description>
  </property>
  <property>
      <name>hfile.format.version</name>
      <value>3</value>
      <description>The HFile format version to use for new files.
      Version 3 adds support for tags in hfiles (See http://hbase.apache.org/book.html#hbase.tags).
      Also see the configuration 'hbase.replication.rpc.codec'.
      </description>
  </property>
  <property>
      <name>hfile.block.bloom.cacheonwrite</name>
      <value>false</value>
      <description>Enables cache-on-write for inline blocks of a compound Bloom filter.</description>
  </property>
  <property>
      <name>io.storefile.bloom.block.size</name>
      <value>131072</value>
      <description>The size in bytes of a single block ("chunk") of a compound Bloom
          filter. This size is approximate, because Bloom blocks can only be
          inserted at data block boundaries, and the number of keys per data
          block varies.</description>
  </property>
  <property>
      <name>hbase.rs.cacheblocksonwrite</name>
      <value>false</value>
      <description>Whether an HFile block should be added to the block cache when the
        block is finished.</description>
  </property>
  <property>
    <name>hbase.rpc.timeout</name>
    <value>60000</value>
    <description>This is for the RPC layer to define how long (millisecond) HBase client applications
        take for a remote call to time out. It uses pings to check connections
        but will eventually throw a TimeoutException.</description>
  </property>
  <property>
    <name>hbase.client.operation.timeout</name>
    <value>1200000</value>
    <description>Operation timeout is a top-level restriction (millisecond) that makes sure a
      blocking operation in Table will not be blocked more than this. In each operation, if rpc
      request fails because of timeout or other reason, it will retry until success or throw
      RetriesExhaustedException. But if the total time being blocking reach the operation timeout
      before retries exhausted, it will break early and throw SocketTimeoutException.</description>
  </property>
  <property>
    <name>hbase.cells.scanned.per.heartbeat.check</name>
    <value>10000</value>
    <description>The number of cells scanned in between heartbeat checks. Heartbeat
        checks occur during the processing of scans to determine whether or not the
        server should stop scanning in order to send back a heartbeat message to the
        client. Heartbeat messages are used to keep the client-server connection alive
        during long running scans. Small values mean that the heartbeat checks will
        occur more often and thus will provide a tighter bound on the execution time of
        the scan. Larger values mean that the heartbeat checks occur less frequently
        </description>
  </property>
  <property>
    <name>hbase.rpc.shortoperation.timeout</name>
    <value>10000</value>
    <description>This is another version of "hbase.rpc.timeout". For those RPC operation
        within cluster, we rely on this configuration to set a short timeout limitation
        for short operation. For example, short rpc timeout for region server's trying
        to report to active master can benefit quicker master failover process.</description>
  </property>
  <property>
    <name>hbase.ipc.client.tcpnodelay</name>
    <value>true</value>
    <description>Set no delay on rpc socket connections.  See
    http://docs.oracle.com/javase/1.5.0/docs/api/java/net/Socket.html#getTcpNoDelay()</description>
  </property>
  <property>
    <name>hbase.regionserver.hostname</name>
    <value></value>
    <description>This config is for experts: don't set its value unless you really know what you are doing.
    When set to a non-empty value, this represents the (external facing) hostname for the underlying server.
    See https://issues.apache.org/jira/browse/HBASE-12954 for details.</description>
  </property>
  <property>
    <name>hbase.regionserver.hostname.disable.master.reversedns</name>
    <value>false</value>
    <description>This config is for experts: don't set its value unless you really know what you are doing.
    When set to true, regionserver will use the current node hostname for the servername and HMaster will
    skip reverse DNS lookup and use the hostname sent by regionserver instead. Note that this config and
    hbase.regionserver.hostname are mutually exclusive. See https://issues.apache.org/jira/browse/HBASE-18226
    for more details.</description>
  </property>
  <!-- The following properties configure authentication information for
       HBase processes when using Kerberos security.  There are no default
       values, included here for documentation purposes -->
  <property>
    <name>hbase.master.keytab.file</name>
    <value></value>
    <description>Full path to the kerberos keytab file to use for logging in
    the configured HMaster server principal.</description>
  </property>
  <property>
    <name>hbase.master.kerberos.principal</name>
    <value></value>
    <description>Ex. "hbase/_HOST@EXAMPLE.COM".  The kerberos principal name
    that should be used to run the HMaster process.  The principal name should
    be in the form: user/hostname@DOMAIN.  If "_HOST" is used as the hostname
    portion, it will be replaced with the actual hostname of the running
    instance.</description>
  </property>
  <property>
    <name>hbase.regionserver.keytab.file</name>
    <value></value>
    <description>Full path to the kerberos keytab file to use for logging in
    the configured HRegionServer server principal.</description>
  </property>
  <property>
    <name>hbase.regionserver.kerberos.principal</name>
    <value></value>
    <description>Ex. "hbase/_HOST@EXAMPLE.COM".  The kerberos principal name
    that should be used to run the HRegionServer process.  The principal name
    should be in the form: user/hostname@DOMAIN.  If "_HOST" is used as the
    hostname portion, it will be replaced with the actual hostname of the
    running instance.  An entry for this principal must exist in the file
    specified in hbase.regionserver.keytab.file</description>
  </property>
  <!-- Additional configuration specific to HBase security -->
  <property>
    <name>hadoop.policy.file</name>
    <value>hbase-policy.xml</value>
    <description>The policy configuration file used by RPC servers to make
      authorization decisions on client requests.  Only used when HBase
      security is enabled.</description>
  </property>
  <property>
    <name>hbase.superuser</name>
    <value></value>
    <description>List of users or groups (comma-separated), who are allowed
    full privileges, regardless of stored ACLs, across the cluster.
    Only used when HBase security is enabled.</description>
  </property>
  <property>
    <name>hbase.auth.key.update.interval</name>
    <value>86400000</value>
    <description>The update interval for master key for authentication tokens
    in servers in milliseconds.  Only used when HBase security is enabled.</description>
  </property>
  <property>
    <name>hbase.auth.token.max.lifetime</name>
    <value>604800000</value>
    <description>The maximum lifetime in milliseconds after which an
    authentication token expires.  Only used when HBase security is enabled.</description>
  </property>
  <property>
    <name>hbase.ipc.client.fallback-to-simple-auth-allowed</name>
    <value>false</value>
    <description>When a client is configured to attempt a secure connection, but attempts to
      connect to an insecure server, that server may instruct the client to
      switch to SASL SIMPLE (unsecure) authentication. This setting controls
      whether or not the client will accept this instruction from the server.
      When false (the default), the client will not allow the fallback to SIMPLE
      authentication, and will abort the connection.</description>
  </property>
  <property>
    <name>hbase.ipc.server.fallback-to-simple-auth-allowed</name>
    <value>false</value>
    <description>When a server is configured to require secure connections, it will
      reject connection attempts from clients using SASL SIMPLE (unsecure) authentication.
      This setting allows secure servers to accept SASL SIMPLE connections from clients
      when the client requests.  When false (the default), the server will not allow the fallback
      to SIMPLE authentication, and will reject the connection.  WARNING: This setting should ONLY
      be used as a temporary measure while converting clients over to secure authentication.  It
      MUST BE DISABLED for secure operation.</description>
  </property>
  <property>
    <name>hbase.display.keys</name>
    <value>true</value>
    <description>When this is set to true the webUI and such will display all start/end keys
                 as part of the table details, region names, etc. When this is set to false,
                 the keys are hidden.</description>
  </property>
  <property>
    <name>hbase.coprocessor.enabled</name>
    <value>true</value>
    <description>Enables or disables coprocessor loading. If 'false'
    (disabled), any other coprocessor related configuration will be ignored.
    </description>
  </property>
  <property>
    <name>hbase.coprocessor.user.enabled</name>
    <value>true</value>
    <description>Enables or disables user (aka. table) coprocessor loading.
    If 'false' (disabled), any table coprocessor attributes in table
    descriptors will be ignored. If "hbase.coprocessor.enabled" is 'false'
    this setting has no effect.
    </description>
  </property>
  <property>
    <name>hbase.coprocessor.region.classes</name>
    <value></value>
    <description>A comma-separated list of region observer or endpoint coprocessors
    that are loaded by default on all tables. For any override coprocessor method,
    these classes will be called in order. After implementing your own Coprocessor,
    add it to HBase's classpath and add the fully qualified class name here.
    A coprocessor can also be loaded on demand by setting HTableDescriptor or the
    HBase shell.</description>
  </property>
  <property>
    <name>hbase.coprocessor.master.classes</name>
    <value></value>
    <description>A comma-separated list of
    org.apache.hadoop.hbase.coprocessor.MasterObserver coprocessors that are
    loaded by default on the active HMaster process. For any implemented
    coprocessor methods, the listed classes will be called in order. After
    implementing your own MasterObserver, just put it in HBase's classpath
    and add the fully qualified class name here.</description>
  </property>
  <property>
      <name>hbase.coprocessor.abortonerror</name>
      <value>true</value>
      <description>Set to true to cause the hosting server (master or regionserver)
      to abort if a coprocessor fails to load, fails to initialize, or throws an
      unexpected Throwable object. Setting this to false will allow the server to
      continue execution but the system wide state of the coprocessor in question
      will become inconsistent as it will be properly executing in only a subset
      of servers, so this is most useful for debugging only.</description>
  </property>
  <property>
    <name>hbase.rest.port</name>
    <value>8080</value>
    <description>The port for the HBase REST server.</description>
  </property>
  <property>
    <name>hbase.rest.readonly</name>
    <value>false</value>
    <description>Defines the mode the REST server will be started in. Possible values are:
    false: All HTTP methods are permitted - GET/PUT/POST/DELETE.
    true: Only the GET method is permitted.</description>
  </property>
  <property>
    <name>hbase.rest.threads.max</name>
    <value>100</value>
    <description>The maximum number of threads of the REST server thread pool.
        Threads in the pool are reused to process REST requests. This
        controls the maximum number of requests processed concurrently.
        It may help to control the memory used by the REST server to
        avoid OOM issues. If the thread pool is full, incoming requests
        will be queued up and wait for some free threads.</description>
  </property>
  <property>
    <name>hbase.rest.threads.min</name>
    <value>2</value>
    <description>The minimum number of threads of the REST server thread pool.
        The thread pool always has at least these number of threads so
        the REST server is ready to serve incoming requests.</description>
  </property>
  <property>
    <name>hbase.rest.support.proxyuser</name>
    <value>false</value>
    <description>Enables running the REST server to support proxy-user mode.</description>
  </property>
  <property skipInDoc="true">
    <name>hbase.defaults.for.version</name>
    <value>@@@VERSION@@@</value>
    <description>This defaults file was compiled for version ${project.version}. This variable is used
    to make sure that a user doesn't have an old version of hbase-default.xml on the
    classpath.</description>
  </property>
  <property>
    <name>hbase.defaults.for.version.skip</name>
    <value>false</value>
    <description>Set to true to skip the 'hbase.defaults.for.version' check.
    Setting this to true can be useful in contexts other than
    the other side of a maven generation; i.e. running in an
    IDE.  You'll want to set this boolean to true to avoid
    seeing the RuntimeException complaint: "hbase-default.xml file
    seems to be for and old version of HBase (\${hbase.version}), this
    version is X.X.X-SNAPSHOT"</description>
  </property>
  <property>
    <name>hbase.table.lock.enable</name>
    <value>true</value>
    <description>Set to true to enable locking the table in zookeeper for schema change operations.
    Table locking from master prevents concurrent schema modifications to corrupt table
    state.</description>
  </property>
  <property>
    <name>hbase.table.max.rowsize</name>
    <value>1073741824</value>
    <description>
      Maximum size of single row in bytes (default is 1 Gb) for Get'ting
      or Scan'ning without in-row scan flag set. If row size exceeds this limit
      RowTooBigException is thrown to client.
    </description>
  </property>
  <property>
    <name>hbase.thrift.minWorkerThreads</name>
    <value>16</value>
    <description>The "core size" of the thread pool. New threads are created on every
    connection until this many threads are created.</description>
  </property>
  <property>
    <name>hbase.thrift.maxWorkerThreads</name>
    <value>1000</value>
    <description>The maximum size of the thread pool. When the pending request queue
    overflows, new threads are created until their number reaches this number.
    After that, the server starts dropping connections.</description>
  </property>
  <property>
    <name>hbase.thrift.maxQueuedRequests</name>
    <value>1000</value>
    <description>The maximum number of pending Thrift connections waiting in the queue. If
     there are no idle threads in the pool, the server queues requests. Only
     when the queue overflows, new threads are added, up to
     hbase.thrift.maxQueuedRequests threads.</description>
  </property>
  <property>
    <name>hbase.regionserver.thrift.framed</name>
    <value>false</value>
    <description>Use Thrift TFramedTransport on the server side.
      This is the recommended transport for thrift servers and requires a similar setting
      on the client side. Changing this to false will select the default transport,
      vulnerable to DoS when malformed requests are issued due to THRIFT-601.
    </description>
  </property>
  <property>
   <name>hbase.regionserver.thrift.framed.max_frame_size_in_mb</name>
    <value>2</value>
    <description>Default frame size when using framed transport, in MB</description>
  </property>
  <property>
    <name>hbase.regionserver.thrift.compact</name>
    <value>false</value>
    <description>Use Thrift TCompactProtocol binary serialization protocol.</description>
  </property>
  <property>
    <name>hbase.rootdir.perms</name>
    <value>700</value>
    <description>FS Permissions for the root data subdirectory in a secure (kerberos) setup.
    When master starts, it creates the rootdir with this permissions or sets the permissions
    if it does not match.</description>
  </property>
  <property>
    <name>hbase.wal.dir.perms</name>
    <value>700</value>
    <description>FS Permissions for the root WAL directory in a secure(kerberos) setup.
      When master starts, it creates the WAL dir with this permissions or sets the permissions
      if it does not match.</description>
  </property>
  <property>
    <name>hbase.data.umask.enable</name>
    <value>false</value>
    <description>Enable, if true, that file permissions should be assigned
      to the files written by the regionserver</description>
  </property>
  <property>
    <name>hbase.data.umask</name>
    <value>000</value>
    <description>File permissions that should be used to write data
      files when hbase.data.umask.enable is true</description>
  </property>
  <property>
    <name>hbase.snapshot.enabled</name>
    <value>true</value>
    <description>Set to true to allow snapshots to be taken / restored / cloned.</description>
  </property>
  <property>
    <name>hbase.snapshot.restore.take.failsafe.snapshot</name>
    <value>true</value>
    <description>Set to true to take a snapshot before the restore operation.
      The snapshot taken will be used in case of failure, to restore the previous state.
      At the end of the restore operation this snapshot will be deleted</description>
  </property>
  <property>
    <name>hbase.snapshot.restore.failsafe.name</name>
    <value>hbase-failsafe-{snapshot.name}-{restore.timestamp}</value>
    <description>Name of the failsafe snapshot taken by the restore operation.
      You can use the {snapshot.name}, {table.name} and {restore.timestamp} variables
      to create a name based on what you are restoring.</description>
  </property>
  <property>
    <name>hbase.server.compactchecker.interval.multiplier</name>
    <value>1000</value>
    <description>The number that determines how often we scan to see if compaction is necessary.
        Normally, compactions are done after some events (such as memstore flush), but if
        region didn't receive a lot of writes for some time, or due to different compaction
        policies, it may be necessary to check it periodically. The interval between checks is
        hbase.server.compactchecker.interval.multiplier multiplied by
        hbase.server.thread.wakefrequency.</description>
  </property>
  <property>
    <name>hbase.lease.recovery.timeout</name>
    <value>900000</value>
    <description>How long we wait on dfs lease recovery in total before giving up.</description>
  </property>
  <property>
    <name>hbase.lease.recovery.dfs.timeout</name>
    <value>64000</value>
    <description>How long between dfs recover lease invocations. Should be larger than the sum of
        the time it takes for the namenode to issue a block recovery command as part of
        datanode; dfs.heartbeat.interval and the time it takes for the primary
        datanode, performing block recovery to timeout on a dead datanode; usually
        dfs.client.socket-timeout. See the end of HBASE-8389 for more.</description>
  </property>
  <property>
    <name>hbase.column.max.version</name>
    <value>1</value>
    <description>New column family descriptors will use this value as the default number of versions
      to keep.</description>
  </property>
  <property>
    <name>dfs.client.read.shortcircuit</name>
    <value>false</value>
    <description>
      If set to true, this configuration parameter enables short-circuit local
      reads.
    </description>
  </property>
  <property>
    <name>dfs.domain.socket.path</name>
    <value>none</value>
    <description>
      This is a path to a UNIX domain socket that will be used for
      communication between the DataNode and local HDFS clients, if
      dfs.client.read.shortcircuit is set to true. If the string "_PORT" is
      present in this path, it will be replaced by the TCP port of the DataNode.
      Be careful about permissions for the directory that hosts the shared
      domain socket; dfsclient will complain if open to other users than the HBase user.
    </description>
  </property>
  <property>
    <name>hbase.dfs.client.read.shortcircuit.buffer.size</name>
    <value>131072</value>
    <description>If the DFSClient configuration
    dfs.client.read.shortcircuit.buffer.size is unset, we will
    use what is configured here as the short circuit read default
    direct byte buffer size. DFSClient native default is 1MB; HBase
    keeps its HDFS files open so number of file blocks * 1MB soon
    starts to add up and threaten OOME because of a shortage of
    direct memory.  So, we set it down from the default.  Make
    it > the default hbase block size set in the HColumnDescriptor
    which is usually 64k.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.checksum.verify</name>
    <value>true</value>
    <description>
        If set to true (the default), HBase verifies the checksums for hfile
        blocks. HBase writes checksums inline with the data when it writes out
        hfiles. HDFS (as of this writing) writes checksums to a separate file
        than the data file necessitating extra seeks.  Setting this flag saves
        some on i/o.  Checksum verification by HDFS will be internally disabled
        on hfile streams when this flag is set.  If the hbase-checksum verification
        fails, we will switch back to using HDFS checksums (so do not disable HDFS
        checksums!  And besides this feature applies to hfiles only, not to WALs).
        If this parameter is set to false, then hbase will not verify any checksums,
        instead it will depend on checksum verification being done in the HDFS client.
    </description>
  </property>
  <property>
    <name>hbase.hstore.bytes.per.checksum</name>
    <value>16384</value>
    <description>
        Number of bytes in a newly created checksum chunk for HBase-level
        checksums in hfile blocks.
    </description>
  </property>
  <property>
    <name>hbase.hstore.checksum.algorithm</name>
    <value>CRC32C</value>
    <description>
      Name of an algorithm that is used to compute checksums. Possible values
      are NULL, CRC32, CRC32C.
    </description>
  </property>
  <property>
    <name>hbase.client.scanner.max.result.size</name>
    <value>2097152</value>
    <description>Maximum number of bytes returned when calling a scanner's next method.
    Note that when a single row is larger than this limit the row is still returned completely.
    The default value is 2MB, which is good for 1ge networks.
    With faster and/or high latency networks this value should be increased.
    </description>
  </property>
  <property>
    <name>hbase.server.scanner.max.result.size</name>
    <value>104857600</value>
    <description>Maximum number of bytes returned when calling a scanner's next method.
    Note that when a single row is larger than this limit the row is still returned completely.
    The default value is 100MB.
    This is a safety setting to protect the server from OOM situations.
    </description>
  </property>
  <property>
    <name>hbase.status.published</name>
    <value>false</value>
    <description>
      This setting activates the publication by the master of the status of the region server.
      When a region server dies and its recovery starts, the master will push this information
      to the client application, to let them cut the connection immediately instead of waiting
      for a timeout.
    </description>
  </property>
  <property>
    <name>hbase.status.publisher.class</name>
    <value>org.apache.hadoop.hbase.master.ClusterStatusPublisher$MulticastPublisher</value>
    <description>
      Implementation of the status publication with a multicast message.
    </description>
  </property>
  <property>
    <name>hbase.status.listener.class</name>
    <value>org.apache.hadoop.hbase.client.ClusterStatusListener$MulticastListener</value>
    <description>
      Implementation of the status listener with a multicast message.
    </description>
  </property>
  <property>
    <name>hbase.status.multicast.address.ip</name>
    <value>226.1.1.3</value>
    <description>
      Multicast address to use for the status publication by multicast.
    </description>
  </property>
  <property>
    <name>hbase.status.multicast.address.port</name>
    <value>16100</value>
    <description>
      Multicast port to use for the status publication by multicast.
    </description>
  </property>
  <property>
    <name>hbase.dynamic.jars.dir</name>
    <value>${hbase.rootdir}/lib</value>
    <description>
      The directory from which the custom filter JARs can be loaded
      dynamically by the region server without the need to restart. However,
      an already loaded filter/co-processor class would not be un-loaded. See
      HBASE-1936 for more details.

      Does not apply to coprocessors.
    </description>
  </property>
  <property>
    <name>hbase.security.authentication</name>
    <value>simple</value>
    <description>
      Controls whether or not secure authentication is enabled for HBase.
      Possible values are 'simple' (no authentication), and 'kerberos'.
    </description>
  </property>
  <property>
    <name>hbase.rest.filter.classes</name>
    <value>org.apache.hadoop.hbase.rest.filter.GzipFilter</value>
    <description>
      Servlet filters for REST service.
    </description>
  </property>
  <property>
    <name>hbase.master.loadbalancer.class</name>
    <value>org.apache.hadoop.hbase.master.balancer.StochasticLoadBalancer</value>
    <description>
      Class used to execute the regions balancing when the period occurs.
      See the class comment for more on how it works
      http://hbase.apache.org/devapidocs/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.html
      It replaces the DefaultLoadBalancer as the default (since renamed
      as the SimpleLoadBalancer).
    </description>
  </property>
  <property>
    <name>hbase.master.loadbalance.bytable</name>
    <value>false</value>
    <description>Factor Table name when the balancer runs.
      Default: false.
    </description>
  </property>
  <property>
    <name>hbase.master.normalizer.class</name>
    <value>org.apache.hadoop.hbase.master.normalizer.SimpleRegionNormalizer</value>
    <description>
      Class used to execute the region normalization when the period occurs.
      See the class comment for more on how it works
      http://hbase.apache.org/devapidocs/org/apache/hadoop/hbase/master/normalizer/SimpleRegionNormalizer.html
    </description>
  </property>
<property>
	<name>hbase.rest.csrf.enabled</name>
	<value>false</value>
  <description>
    Set to true to enable protection against cross-site request forgery (CSRF)
	</description>
</property>
<property>
  <name>hbase.rest-csrf.browser-useragents-regex</name>
  <value>^Mozilla.*,^Opera.*</value>
  <description>
    A comma-separated list of regular expressions used to match against an HTTP
    request's User-Agent header when protection against cross-site request
    forgery (CSRF) is enabled for REST server by setting
    hbase.rest.csrf.enabled to true.  If the incoming User-Agent matches
    any of these regular expressions, then the request is considered to be sent
    by a browser, and therefore CSRF prevention is enforced.  If the request's
    User-Agent does not match any of these regular expressions, then the request
    is considered to be sent by something other than a browser, such as scripted
    automation.  In this case, CSRF is not a potential attack vector, so
    the prevention is not enforced.  This helps achieve backwards-compatibility
    with existing automation that has not been updated to send the CSRF
    prevention header.
  </description>
</property>
  <property>
    <name>hbase.security.exec.permission.checks</name>
    <value>false</value>
    <description>
      If this setting is enabled and ACL based access control is active (the
      AccessController coprocessor is installed either as a system coprocessor
      or on a table as a table coprocessor) then you must grant all relevant
      users EXEC privilege if they require the ability to execute coprocessor
      endpoint calls. EXEC privilege, like any other permission, can be
      granted globally to a user, or to a user on a per table or per namespace
      basis. For more information on coprocessor endpoints, see the coprocessor
      section of the HBase online manual. For more information on granting or
      revoking permissions using the AccessController, see the security
      section of the HBase online manual.
    </description>
  </property>
  <property>
    <name>hbase.procedure.regionserver.classes</name>
    <value></value>
    <description>A comma-separated list of
    org.apache.hadoop.hbase.procedure.RegionServerProcedureManager procedure managers that are
    loaded by default on the active HRegionServer process. The lifecycle methods (init/start/stop)
    will be called by the active HRegionServer process to perform the specific globally barriered
    procedure. After implementing your own RegionServerProcedureManager, just put it in
    HBase's classpath and add the fully qualified class name here.
    </description>
  </property>
    <property>
    <name>hbase.procedure.master.classes</name>
    <value></value>
    <description>A comma-separated list of
    org.apache.hadoop.hbase.procedure.MasterProcedureManager procedure managers that are
    loaded by default on the active HMaster process. A procedure is identified by its signature and
    users can use the signature and an instant name to trigger an execution of a globally barriered
    procedure. After implementing your own MasterProcedureManager, just put it in HBase's classpath
    and add the fully qualified class name here.</description>
  </property>
  <property>
    <name>hbase.coordinated.state.manager.class</name>
    <value>org.apache.hadoop.hbase.coordination.ZkCoordinatedStateManager</value>
    <description>Fully qualified name of class implementing coordinated state manager.</description>
  </property>
  <property>
    <name>hbase.regionserver.storefile.refresh.period</name>
    <value>0</value>
    <description>
      The period (in milliseconds) for refreshing the store files for the secondary regions. 0
      means this feature is disabled. Secondary regions sees new files (from flushes and
      compactions) from primary once the secondary region refreshes the list of files in the
      region (there is no notification mechanism). But too frequent refreshes might cause
      extra Namenode pressure. If the files cannot be refreshed for longer than HFile TTL
      (hbase.master.hfilecleaner.ttl) the requests are rejected. Configuring HFile TTL to a larger
      value is also recommended with this setting.
    </description>
  </property>
  <property>
    <name>hbase.region.replica.replication.enabled</name>
    <value>false</value>
    <description>
      Whether asynchronous WAL replication to the secondary region replicas is enabled or not.
      If this is enabled, a replication peer named "region_replica_replication" will be created
      which will tail the logs and replicate the mutations to region replicas for tables that
      have region replication > 1. If this is enabled once, disabling this replication also
      requires disabling the replication peer using shell or Admin java class.
      Replication to secondary region replicas works over standard inter-cluster replication.
    </description>
  </property>
  <property>
    <name>hbase.http.filter.initializers</name>
    <value>org.apache.hadoop.hbase.http.lib.StaticUserWebFilter</value>
    <description>
      A comma separated list of class names. Each class in the list must extend
      org.apache.hadoop.hbase.http.FilterInitializer. The corresponding Filter will
      be initialized. Then, the Filter will be applied to all user facing jsp
      and servlet web pages.
      The ordering of the list defines the ordering of the filters.
      The default StaticUserWebFilter add a user principal as defined by the
      hbase.http.staticuser.user property.
    </description>
  </property>
    <property>
    <name>hbase.security.visibility.mutations.checkauths</name>
    <value>false</value>
    <description>
      This property if enabled, will check whether the labels in the visibility
      expression are associated with the user issuing the mutation
    </description>
  </property>
  <property>
    <name>hbase.http.max.threads</name>
    <value>16</value>
    <description>
      The maximum number of threads that the HTTP Server will create in its
      ThreadPool.
    </description>
  </property>
  <property>
  	<name>hbase.replication.rpc.codec</name>
  	<value>org.apache.hadoop.hbase.codec.KeyValueCodecWithTags</value>
  	<description>
  		The codec that is to be used when replication is enabled so that
  		the tags are also replicated. This is used along with HFileV3 which
  		supports tags in them.  If tags are not used or if the hfile version used
  		is HFileV2 then KeyValueCodec can be used as the replication codec. Note that
  		using KeyValueCodecWithTags for replication when there are no tags causes no harm.
  	</description>
  </property>
  <property>
    <name>hbase.replication.source.maxthreads</name>
    <value>10</value>
    <description>
        The maximum number of threads any replication source will use for
        shipping edits to the sinks in parallel. This also limits the number of
        chunks each replication batch is broken into. Larger values can improve
        the replication throughput between the master and slave clusters. The
        default of 10 will rarely need to be changed.
    </description>
  </property>
  <!-- Static Web User Filter properties. -->
  <property>
    <name>hbase.http.staticuser.user</name>
    <value>dr.stack</value>
    <description>
      The user name to filter as, on static web filters
      while rendering content. An example use is the HDFS
      web UI (user to be used for browsing files).
    </description>
  </property>
  <property>
    <name>hbase.regionserver.handler.abort.on.error.percent</name>
    <value>0.5</value>
    <description>The percent of region server RPC threads failed to abort RS.
    -1 Disable aborting; 0 Abort if even a single handler has died;
    0.x Abort only when this percent of handlers have died;
    1 Abort only all of the handers have died.</description>
  </property>
  <!-- Mob properties. -->
  <property>
    <name>hbase.mob.file.cache.size</name>
    <value>1000</value>
    <description>
      Number of opened file handlers to cache.
      A larger value will benefit reads by providing more file handlers per mob
      file cache and would reduce frequent file opening and closing.
      However, if this is set too high, this could lead to a "too many opened file handlers"
      The default value is 1000.
    </description>
  </property>
  <property>
    <name>hbase.mob.cache.evict.period</name>
    <value>3600</value>
    <description>
      The amount of time in seconds before the mob cache evicts cached mob files.
      The default value is 3600 seconds.
    </description>
  </property>
  <property>
    <name>hbase.mob.cache.evict.remain.ratio</name>
    <value>0.5f</value>
    <description>
      The ratio (between 0.0 and 1.0) of files that remains cached after an eviction
      is triggered when the number of cached mob files exceeds the hbase.mob.file.cache.size.
      The default value is 0.5f.
    </description>
  </property>
  <property>
    <name>hbase.master.mob.ttl.cleaner.period</name>
    <value>86400</value>
    <description>
      The period that ExpiredMobFileCleanerChore runs. The unit is second.
      The default value is one day. The MOB file name uses only the date part of
      the file creation time in it. We use this time for deciding TTL expiry of
      the files. So the removal of TTL expired files might be delayed. The max
      delay might be 24 hrs.
    </description>
  </property>
  <property>
    <name>hbase.mob.compaction.mergeable.threshold</name>
    <value>1342177280</value>
    <description>
      If the size of a mob file is less than this value, it's regarded as a small
      file and needs to be merged in mob compaction. The default value is 1280MB.
    </description>
  </property>
  <property>
    <name>hbase.mob.delfile.max.count</name>
    <value>3</value>
    <description>
      The max number of del files that is allowed in the mob compaction.
      In the mob compaction, when the number of existing del files is larger than
      this value, they are merged until number of del files is not larger this value.
      The default value is 3.
    </description>
  </property>
  <property>
    <name>hbase.mob.compaction.batch.size</name>
    <value>100</value>
    <description>
      The max number of the mob files that is allowed in a batch of the mob compaction.
      The mob compaction merges the small mob files to bigger ones. If the number of the
      small files is very large, it could lead to a "too many opened file handlers" in the merge.
      And the merge has to be split into batches. This value limits the number of mob files
      that are selected in a batch of the mob compaction. The default value is 100.
    </description>
  </property>
  <property>
    <name>hbase.mob.compaction.chore.period</name>
    <value>604800</value>
    <description>
      The period that MobCompactionChore runs. The unit is second.
      The default value is one week.
    </description>
  </property>
  <property>
    <name>hbase.mob.compactor.class</name>
    <value>org.apache.hadoop.hbase.mob.compactions.PartitionedMobCompactor</value>
    <description>
      Implementation of mob compactor, the default one is PartitionedMobCompactor.
    </description>
  </property>
  <property>
    <name>hbase.mob.compaction.threads.max</name>
    <value>1</value>
    <description>
      The max number of threads used in MobCompactor.
    </description>
  </property>
  <property>
    <name>hbase.snapshot.master.timeout.millis</name>
    <value>300000</value>
    <description>
       Timeout for master for the snapshot procedure execution.
    </description>
   </property>
     <property>
    <name>hbase.snapshot.region.timeout</name>
    <value>300000</value>
    <description>
       Timeout for regionservers to keep threads in snapshot request pool waiting.
    </description>
   </property>
   <property>
    <name>hbase.rpc.rows.warning.threshold</name>
    <value>5000</value>
    <description>
      Number of rows in a batch operation above which a warning will be logged.
    </description>
  </property>
  <property>
    <name>hbase.master.wait.on.service.seconds</name>
    <value>30</value>
    <description>Default is 5 minutes. Make it 30 seconds for tests. See
    HBASE-19794 for some context.</description>
  </property>
</configuration>