HBASE-26265 Update ref guide to mention the new store file tracker im… (#3942)

[hbase.git] / src / main / asciidoc / _chapters / hbase-default.adoc

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 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
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 * with the License.  You may obtain a copy of the License at
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 *     http://www.apache.org/licenses/LICENSE-2.0
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:doctype: book
:numbered:
:toc: left
:icons: font
:experimental:

[[hbase_default_configurations]]
=== HBase Default Configuration

The documentation below is generated using the default hbase configuration file, _hbase-default.xml_, as source.


[[hbase.tmp.dir]]
*`hbase.tmp.dir`*::
+
.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.
+
.Default
`${java.io.tmpdir}/hbase-${user.name}`


[[hbase.rootdir]]
*`hbase.rootdir`*::
+
.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 ${hbase.tmp.dir} is set to -- usually /tmp --
    so change this configuration or else all data will be lost on
    machine restart.
+
.Default
`${hbase.tmp.dir}/hbase`


[[hbase.cluster.distributed]]
*`hbase.cluster.distributed`*::
+
.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 one JVM.
+
.Default
`false`


[[hbase.zookeeper.quorum]]
*`hbase.zookeeper.quorum`*::
+
.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.clientPort
    config and pass it into zookeeper constructor as the connectString
    parameter.
+
.Default
`localhost`


[[hbase.local.dir]]
*`hbase.local.dir`*::
+
.Description
Directory on the local filesystem to be used
    as a local storage.
+
.Default
`${hbase.tmp.dir}/local/`


[[hbase.master.info.port]]
*`hbase.master.info.port`*::
+
.Description
The port for the HBase Master web UI.
    Set to -1 if you do not want a UI instance run.
+
.Default
`16010`


[[hbase.master.info.bindAddress]]
*`hbase.master.info.bindAddress`*::
+
.Description
The bind address for the HBase Master web UI

+
.Default
`0.0.0.0`


[[hbase.master.logcleaner.plugins]]
*`hbase.master.logcleaner.plugins`*::
+
.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.
+
.Default
`org.apache.hadoop.hbase.master.cleaner.TimeToLiveLogCleaner`


[[hbase.master.logcleaner.ttl]]
*`hbase.master.logcleaner.ttl`*::
+
.Description
Maximum time a WAL can stay in the oldWALs directory,
    after which it will be cleaned by a Master thread.
+
.Default
`600000`


[[hbase.master.hfilecleaner.plugins]]
*`hbase.master.hfilecleaner.plugins`*::
+
.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.
+
.Default
`org.apache.hadoop.hbase.master.cleaner.TimeToLiveHFileCleaner`


[[hbase.master.infoserver.redirect]]
*`hbase.master.infoserver.redirect`*::
+
.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.
+
.Default
`true`


[[hbase.regionserver.port]]
*`hbase.regionserver.port`*::
+
.Description
The port the HBase RegionServer binds to.
+
.Default
`16020`


[[hbase.regionserver.info.port]]
*`hbase.regionserver.info.port`*::
+
.Description
The port for the HBase RegionServer web UI
    Set to -1 if you do not want the RegionServer UI to run.
+
.Default
`16030`


[[hbase.regionserver.info.bindAddress]]
*`hbase.regionserver.info.bindAddress`*::
+
.Description
The address for the HBase RegionServer web UI
+
.Default
`0.0.0.0`


[[hbase.regionserver.info.port.auto]]
*`hbase.regionserver.info.port.auto`*::
+
.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.
+
.Default
`false`


[[hbase.regionserver.handler.count]]
*`hbase.regionserver.handler.count`*::
+
.Description
Count of RPC Listener instances spun up on RegionServers.
    Same property is used by the Master for count of master handlers.
+
.Default
`30`


[[hbase.ipc.server.callqueue.handler.factor]]
*`hbase.ipc.server.callqueue.handler.factor`*::
+
.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.
+
.Default
`0.1`


[[hbase.ipc.server.callqueue.read.ratio]]
*`hbase.ipc.server.callqueue.read.ratio`*::
+
.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 indicates 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.

+
.Default
`0`


[[hbase.ipc.server.callqueue.scan.ratio]]
*`hbase.ipc.server.callqueue.scan.ratio`*::
+
.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 indicates 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.

+
.Default
`0`


[[hbase.regionserver.msginterval]]
*`hbase.regionserver.msginterval`*::
+
.Description
Interval between messages from the RegionServer to Master
    in milliseconds.
+
.Default
`3000`


[[hbase.regionserver.regionSplitLimit]]
*`hbase.regionserver.regionSplitLimit`*::
+
.Description
Limit for the number of regions after which no more region
    splitting should take place. This is not a hard limit for the number of
    regions but acts as a guideline for the regionserver to stop splitting after
    a certain limit. Default is MAX_INT; i.e. do not block splitting.
+
.Default
`2147483647`


[[hbase.regionserver.logroll.period]]
*`hbase.regionserver.logroll.period`*::
+
.Description
Period at which we will roll the commit log regardless
    of how many edits it has.
+
.Default
`3600000`


[[hbase.regionserver.logroll.errors.tolerated]]
*`hbase.regionserver.logroll.errors.tolerated`*::
+
.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.
+
.Default
`2`


[[hbase.regionserver.hlog.reader.impl]]
*`hbase.regionserver.hlog.reader.impl`*::
+
.Description
The WAL file reader implementation.
+
.Default
`org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader`


[[hbase.regionserver.hlog.writer.impl]]
*`hbase.regionserver.hlog.writer.impl`*::
+
.Description
The WAL file writer implementation.
+
.Default
`org.apache.hadoop.hbase.regionserver.wal.ProtobufLogWriter`

[[hbase.regionserver.global.memstore.size]]
*`hbase.regionserver.global.memstore.size`*::
+
.Description
Maximum size of all memstores in a region server before new
      updates are blocked and flushes are forced. Defaults to 40% of heap.
      Updates are blocked and flushes are forced until size of all memstores
      in a region server hits hbase.regionserver.global.memstore.size.lower.limit.
+
.Default
`0.4`


[[hbase.regionserver.global.memstore.size.lower.limit]]
*`hbase.regionserver.global.memstore.size.lower.limit`*::
+
.Description
Maximum size of all memstores in a region server before flushes are forced.
      Defaults to 95% of hbase.regionserver.global.memstore.size.
      A 100% value for this property causes the minimum possible flushing to occur when updates are
      blocked due to memstore limiting.
+
.Default
`0.95`


[[hbase.regionserver.optionalcacheflushinterval]]
*`hbase.regionserver.optionalcacheflushinterval`*::
+
.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.
+
.Default
`3600000`


[[hbase.regionserver.dns.interface]]
*`hbase.regionserver.dns.interface`*::
+
.Description
The name of the Network Interface from which a region server
      should report its IP address.
+
.Default
`default`


[[hbase.regionserver.dns.nameserver]]
*`hbase.regionserver.dns.nameserver`*::
+
.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.
+
.Default
`default`


[[hbase.regionserver.region.split.policy]]
*`hbase.regionserver.region.split.policy`*::
+
.Description

      A split policy determines when a region should be split. The various other split policies that
      are available currently are ConstantSizeRegionSplitPolicy, DisabledRegionSplitPolicy,
      DelimitedKeyPrefixRegionSplitPolicy, KeyPrefixRegionSplitPolicy,
      BusyRegionSplitPolicy, SteppingSplitPolicy etc.

+
.Default
`org.apache.hadoop.hbase.regionserver.SteppingSplitPolicy`


[[zookeeper.session.timeout]]
*`zookeeper.session.timeout`*::
+
.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
      https://zookeeper.apache.org/doc/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 maxSessionTimeout that ZK ships with is 40 seconds, which is lower than HBase's.

+
.Default
`90000`


[[zookeeper.znode.parent]]
*`zookeeper.znode.parent`*::
+
.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 path are configured with a
      relative path, so they will all go under this directory unless changed.
+
.Default
`/hbase`


[[zookeeper.znode.acl.parent]]
*`zookeeper.znode.acl.parent`*::
+
.Description
Root ZNode for access control lists.
+
.Default
`acl`


[[hbase.zookeeper.dns.interface]]
*`hbase.zookeeper.dns.interface`*::
+
.Description
The name of the Network Interface from which a ZooKeeper server
      should report its IP address.
+
.Default
`default`


[[hbase.zookeeper.dns.nameserver]]
*`hbase.zookeeper.dns.nameserver`*::
+
.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.
+
.Default
`default`


[[hbase.zookeeper.peerport]]
*`hbase.zookeeper.peerport`*::
+
.Description
Port used by ZooKeeper peers to talk to each other.
    See https://zookeeper.apache.org/doc/r3.4.10/zookeeperStarted.html#sc_RunningReplicatedZooKeeper
    for more information.
+
.Default
`2888`


[[hbase.zookeeper.leaderport]]
*`hbase.zookeeper.leaderport`*::
+
.Description
Port used by ZooKeeper for leader election.
    See https://zookeeper.apache.org/doc/r3.4.10/zookeeperStarted.html#sc_RunningReplicatedZooKeeper
    for more information.
+
.Default
`3888`


[[hbase.zookeeper.useMulti]]
*`hbase.zookeeper.useMulti`*::
+
.Description
Instructs HBase to make use of ZooKeeper's multi-update functionality.
    This allows certain ZooKeeper operations to complete more quickly and prevents some issues
    with rare Replication failure scenarios (see the release note of HBASE-2611 for an example).
    IMPORTANT: only set this to true if all ZooKeeper servers in the cluster are on version 3.4+
    and will not be downgraded.  ZooKeeper versions before 3.4 do not support multi-update and
    will not fail gracefully if multi-update is invoked (see ZOOKEEPER-1495).
+
.Default
`true`


[[hbase.zookeeper.property.initLimit]]
*`hbase.zookeeper.property.initLimit`*::
+
.Description
Property from ZooKeeper's config zoo.cfg.
    The number of ticks that the initial synchronization phase can take.
+
.Default
`10`


[[hbase.zookeeper.property.syncLimit]]
*`hbase.zookeeper.property.syncLimit`*::
+
.Description
Property from ZooKeeper's config zoo.cfg.
    The number of ticks that can pass between sending a request and getting an
    acknowledgment.
+
.Default
`5`


[[hbase.zookeeper.property.dataDir]]
*`hbase.zookeeper.property.dataDir`*::
+
.Description
Property from ZooKeeper's config zoo.cfg.
    The directory where the snapshot is stored.
+
.Default
`${hbase.tmp.dir}/zookeeper`


[[hbase.zookeeper.property.clientPort]]
*`hbase.zookeeper.property.clientPort`*::
+
.Description
Property from ZooKeeper's config zoo.cfg.
    The port at which the clients will connect.
+
.Default
`2181`


[[hbase.zookeeper.property.maxClientCnxns]]
*`hbase.zookeeper.property.maxClientCnxns`*::
+
.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.
+
.Default
`300`


[[hbase.client.write.buffer]]
*`hbase.client.write.buffer`*::
+
.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
+
.Default
`2097152`


[[hbase.client.pause]]
*`hbase.client.pause`*::
+
.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.
+
.Default
`100`


[[hbase.client.retries.number]]
*`hbase.client.retries.number`*::
+
.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.
+
.Default
`35`


[[hbase.client.max.total.tasks]]
*`hbase.client.max.total.tasks`*::
+
.Description
The maximum number of concurrent tasks a single HTable instance will
    send to the cluster.
+
.Default
`100`


[[hbase.client.max.perserver.tasks]]
*`hbase.client.max.perserver.tasks`*::
+
.Description
The maximum number of concurrent tasks a single HTable instance will
    send to a single region server.
+
.Default
`2`


[[hbase.client.max.perregion.tasks]]
*`hbase.client.max.perregion.tasks`*::
+
.Description
The maximum number of concurrent connections 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 finish.
+
.Default
`1`


[[hbase.client.scanner.caching]]
*`hbase.client.scanner.caching`*::
+
.Description
Number of rows that will be fetched when calling next
    on a scanner if it is not served from (local, client) memory. 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
+
.Default
`100`


[[hbase.client.keyvalue.maxsize]]
*`hbase.client.keyvalue.maxsize`*::
+
.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.
+
.Default
`10485760`


[[hbase.client.scanner.timeout.period]]
*`hbase.client.scanner.timeout.period`*::
+
.Description
Client scanner lease period in milliseconds.
+
.Default
`60000`


[[hbase.client.localityCheck.threadPoolSize]]
*`hbase.client.localityCheck.threadPoolSize`*::
+
.Description

+
.Default
`2`


[[hbase.bulkload.retries.number]]
*`hbase.bulkload.retries.number`*::
+
.Description
Maximum retries. This is a maximum number of iterations
    atomic bulk loads are attempted in the face of splitting operations,
    0 means never give up.
+
.Default
`10`


[[hbase.compaction.after.bulkload.enable]]
*`hbase.compaction.after.bulkload.enable`*::
+
.Description
Request Compaction after bulkload immediately.
If bulkload is continuous, the triggered compactions may increase load,
bring about performance side effect.
(For HBase-2.x, the default value for "hbase.compaction.after.bulkload.enable" is true)
+
.Default
`false`

[[hbase.balancer.period
    ]]
*`hbase.balancer.period
    `*::
+
.Description
Period at which the region balancer runs in the Master.
+
.Default
`300000`


[[hbase.regions.slop]]
*`hbase.regions.slop`*::
+
.Description
Rebalance if any regionserver has average + (average * slop) regions.
+
.Default
`0.2`


[[hbase.server.thread.wakefrequency]]
*`hbase.server.thread.wakefrequency`*::
+
.Description
Time to sleep in between searches for work (in milliseconds).
    Used as sleep interval by service threads such as log roller.
+
.Default
`10000`


[[hbase.server.versionfile.writeattempts]]
*`hbase.server.versionfile.writeattempts`*::
+
.Description

    How many time to retry attempting to write a version file
    before just aborting. Each attempt is separated by the
    hbase.server.thread.wakefrequency milliseconds.
+
.Default
`3`


[[hbase.hregion.memstore.flush.size]]
*`hbase.hregion.memstore.flush.size`*::
+
.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.
+
.Default
`134217728`


[[hbase.hregion.percolumnfamilyflush.size.lower.bound]]
*`hbase.hregion.percolumnfamilyflush.size.lower.bound`*::
+
.Description

    If FlushLargeStoresPolicy is used, then every time that we hit the
    total memstore limit, we find out all the column families whose memstores
    exceed this value, and only flush them, while retaining the others whose
    memstores are lower than this limit. If none of the families have their
    memstore size more than this, all the memstores will be flushed
    (just as usual). This value should be less than half of the total memstore
    threshold (hbase.hregion.memstore.flush.size).

+
.Default
`16777216`


[[hbase.hregion.preclose.flush.size]]
*`hbase.hregion.preclose.flush.size`*::
+
.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.
+
.Default
`5242880`


[[hbase.hregion.memstore.block.multiplier]]
*`hbase.hregion.memstore.block.multiplier`*::
+
.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.
+
.Default
`4`


[[hbase.hregion.memstore.mslab.enabled]]
*`hbase.hregion.memstore.mslab.enabled`*::
+
.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.
+
.Default
`true`


[[hbase.hregion.max.filesize]]
*`hbase.hregion.max.filesize`*::
+
.Description

    Maximum file size. If the sum of the sizes of a region's HFiles has
    grown to exceed this value, the region is split in two. There are two choices of
    how this option works, the first is when any store's size exceed the threshold
    then split, and the other is overall region's size exceed the threshold then split,
    it can be configed by hbase.hregion.split.overallfiles.
+
.Default
`10737418240`


[[hbase.hregion.split.overallfiles]]
*`hbase.hregion.split.overallfiles`*::
+
.Description

    If we should sum overall region files size when check to split.
+
.Default
`true`


[[hbase.hregion.majorcompaction]]
*`hbase.hregion.majorcompaction`*::
+
.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.
+
.Default
`604800000`


[[hbase.hregion.majorcompaction.jitter]]
*`hbase.hregion.majorcompaction.jitter`*::
+
.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.
+
.Default
`0.50`


[[hbase.hstore.compactionThreshold]]
*`hbase.hstore.compactionThreshold`*::
+
.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.
+
.Default
`3`


[[hbase.hstore.flusher.count]]
*`hbase.hstore.flusher.count`*::
+
.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.
+
.Default
`2`


[[hbase.hstore.blockingStoreFiles]]
*`hbase.hstore.blockingStoreFiles`*::
+
.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.
+
.Default
`10`


[[hbase.hstore.blockingWaitTime]]
*`hbase.hstore.blockingWaitTime`*::
+
.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.
+
.Default
`90000`


[[hbase.hstore.compaction.min]]
*`hbase.hstore.compaction.min`*::
+
.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.
+
.Default
`3`


[[hbase.hstore.compaction.max]]
*`hbase.hstore.compaction.max`*::
+
.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.
+
.Default
`10`


[[hbase.hstore.compaction.min.size]]
*`hbase.hstore.compaction.min.size`*::
+
.Description
A StoreFile 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.
+
.Default
`134217728`


[[hbase.hstore.compaction.max.size]]
*`hbase.hstore.compaction.max.size`*::
+
.Description
A StoreFile 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.
+
.Default
`9223372036854775807`


[[hbase.hstore.compaction.ratio]]
*`hbase.hstore.compaction.ratio`*::
+
.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.
+
.Default
`1.2F`


[[hbase.hstore.compaction.ratio.offpeak]]
*`hbase.hstore.compaction.ratio.offpeak`*::
+
.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.
+
.Default
`5.0F`


[[hbase.hstore.time.to.purge.deletes]]
*`hbase.hstore.time.to.purge.deletes`*::
+
.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.

+
.Default
`0`


[[hbase.offpeak.start.hour]]
*`hbase.offpeak.start.hour`*::
+
.Description
The start of off-peak hours, expressed as an integer between 0 and 23, inclusive.
      Set to -1 to disable off-peak.
+
.Default
`-1`


[[hbase.offpeak.end.hour]]
*`hbase.offpeak.end.hour`*::
+
.Description
The end of off-peak hours, expressed as an integer between 0 and 23, inclusive. Set
      to -1 to disable off-peak.
+
.Default
`-1`


[[hbase.regionserver.thread.compaction.throttle]]
*`hbase.regionserver.thread.compaction.throttle`*::
+
.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.
+
.Default
`2684354560`


[[hbase.hstore.compaction.kv.max]]
*`hbase.hstore.compaction.kv.max`*::
+
.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.
+
.Default
`10`


[[hbase.storescanner.parallel.seek.enable]]
*`hbase.storescanner.parallel.seek.enable`*::
+
.Description

      Enables StoreFileScanner parallel-seeking in StoreScanner,
      a feature which can reduce response latency under special conditions.
+
.Default
`false`


[[hbase.storescanner.parallel.seek.threads]]
*`hbase.storescanner.parallel.seek.threads`*::
+
.Description

      The default thread pool size if parallel-seeking feature enabled.
+
.Default
`10`


[[hfile.block.cache.size]]
*`hfile.block.cache.size`*::
+
.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.
+
.Default
`0.4`


[[hfile.block.index.cacheonwrite]]
*`hfile.block.index.cacheonwrite`*::
+
.Description
This allows to put non-root multi-level index blocks into the block
          cache at the time the index is being written.
+
.Default
`false`


[[hfile.index.block.max.size]]
*`hfile.index.block.max.size`*::
+
.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.
+
.Default
`131072`


[[hbase.bucketcache.ioengine]]
*`hbase.bucketcache.ioengine`*::
+
.Description
Where to store the contents of the bucketcache. One of: offheap,
    file, files, mmap or pmem. 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.
    'pmem' is bucket cache over a file on the persistent memory device.
    Use pmem:PATH_TO_FILE.
    See https://hbase.apache.org/devapidocs/org/apache/hadoop/hbase/io/hfile/CacheConfig.html
    for more information.

+
.Default
``


[[hbase.bucketcache.combinedcache.enabled]]
*`hbase.bucketcache.combinedcache.enabled`*::
+
.Description
Whether or not the bucketcache is used in league with the LRU
      on-heap block cache. In this mode, indices and blooms are kept in the LRU
      blockcache and the data blocks are kept in the bucketcache.
+
.Default
`true`


[[hbase.bucketcache.size]]
*`hbase.bucketcache.size`*::
+
.Description
Used along with bucket cache, this is a float that EITHER represents a percentage of total heap
   memory size to give to the cache (if < 1.0) OR, it is the capacity in megabytes of the cache.
   (After HBase-2.0, "hbase.bucketcache.size" cannot be between 0-1)
+
.Default
`0` when specified as a float


[[hbase.bucketcache.bucket.sizes]]
*`hbase.bucketcache.bucket.sizes`*::
+
.Description
A comma-separated list of sizes for buckets for the bucketcache
      if you use multiple sizes. Should be a list of block sizes in order from smallest
      to largest. The sizes you use will depend on your data access patterns.
+
.Default
``


[[hfile.format.version]]
*`hfile.format.version`*::
+
.Description
The HFile format version to use for new files.
      Version 3 adds support for tags in hfiles (See https://hbase.apache.org/book.html#hbase.tags).
      Also see the configuration 'hbase.replication.rpc.codec'.

+
.Default
`3`


[[hfile.block.bloom.cacheonwrite]]
*`hfile.block.bloom.cacheonwrite`*::
+
.Description
Enables cache-on-write for inline blocks of a compound Bloom filter.
+
.Default
`false`


[[io.storefile.bloom.block.size]]
*`io.storefile.bloom.block.size`*::
+
.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.
+
.Default
`131072`


[[hbase.rs.cacheblocksonwrite]]
*`hbase.rs.cacheblocksonwrite`*::
+
.Description
Whether an HFile block should be added to the block cache when the
          block is finished.
+
.Default
`false`


[[hbase.rpc.timeout]]
*`hbase.rpc.timeout`*::
+
.Description
This is for the RPC layer to define how long HBase client applications
        take for a remote call to time out. It uses pings to check connections
        but will eventually throw a TimeoutException.
+
.Default
`60000`


[[hbase.rpc.shortoperation.timeout]]
*`hbase.rpc.shortoperation.timeout`*::
+
.Description
This is another version of "hbase.rpc.timeout". For those RPC operations
        within cluster, we rely on this configuration to set a short timeout limitation
        for short operations. For example, short rpc timeout for region server trying
        to report to active master can benefit from quicker master failover process.
+
.Default
`10000`


[[hbase.ipc.client.tcpnodelay]]
*`hbase.ipc.client.tcpnodelay`*::
+
.Description
Set no delay on rpc socket connections.  See
    http://docs.oracle.com/javase/8/docs/api/java/net/Socket.html#getTcpNoDelay--
+
.Default
`true`


[[hbase.master.keytab.file]]
*`hbase.master.keytab.file`*::
+
.Description
Full path to the kerberos keytab file to use for logging in
    the configured HMaster server principal.
+
.Default
``


[[hbase.master.kerberos.principal]]
*`hbase.master.kerberos.principal`*::
+
.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.
+
.Default
``


[[hbase.regionserver.keytab.file]]
*`hbase.regionserver.keytab.file`*::
+
.Description
Full path to the kerberos keytab file to use for logging in
    the configured HRegionServer server principal.
+
.Default
``


[[hbase.regionserver.kerberos.principal]]
*`hbase.regionserver.kerberos.principal`*::
+
.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
+
.Default
``


[[hadoop.policy.file]]
*`hadoop.policy.file`*::
+
.Description
The policy configuration file used by RPC servers to make
      authorization decisions on client requests.  Only used when HBase
      security is enabled.
+
.Default
`hbase-policy.xml`


[[hbase.superuser]]
*`hbase.superuser`*::
+
.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.
+
.Default
``


[[hbase.auth.key.update.interval]]
*`hbase.auth.key.update.interval`*::
+
.Description
The update interval for master key for authentication tokens
    in servers in milliseconds.  Only used when HBase security is enabled.
+
.Default
`86400000`


[[hbase.auth.token.max.lifetime]]
*`hbase.auth.token.max.lifetime`*::
+
.Description
The maximum lifetime in milliseconds after which an
    authentication token expires.  Only used when HBase security is enabled.
+
.Default
`604800000`


[[hbase.ipc.client.fallback-to-simple-auth-allowed]]
*`hbase.ipc.client.fallback-to-simple-auth-allowed`*::
+
.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.
+
.Default
`false`


[[hbase.display.keys]]
*`hbase.display.keys`*::
+
.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.
+
.Default
`true`


[[hbase.coprocessor.region.classes]]
*`hbase.coprocessor.region.classes`*::
+
.Description
A comma-separated list of 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, just put
    it in HBase's classpath and add the fully qualified class name here.
    A coprocessor can also be loaded on demand by setting HTableDescriptor.
+
.Default
``


[[hbase.rest.port]]
*`hbase.rest.port`*::
+
.Description
The port for the HBase REST server.
+
.Default
`8080`


[[hbase.rest.readonly]]
*`hbase.rest.readonly`*::
+
.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.
+
.Default
`false`


[[hbase.rest.threads.max]]
*`hbase.rest.threads.max`*::
+
.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.
+
.Default
`100`


[[hbase.rest.threads.min]]
*`hbase.rest.threads.min`*::
+
.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.
+
.Default
`2`


[[hbase.rest.support.proxyuser]]
*`hbase.rest.support.proxyuser`*::
+
.Description
Enables running the REST server to support proxy-user mode.
+
.Default
`false`


[[hbase.defaults.for.version.skip]]
*`hbase.defaults.for.version.skip`*::
+
.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"
+
.Default
`false`


[[hbase.coprocessor.master.classes]]
*`hbase.coprocessor.master.classes`*::
+
.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.
+
.Default
``


[[hbase.coprocessor.abortonerror]]
*`hbase.coprocessor.abortonerror`*::
+
.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.
+
.Default
`true`


[[hbase.table.lock.enable]]
*`hbase.table.lock.enable`*::
+
.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.
+
.Default
`true`


[[hbase.table.max.rowsize]]
*`hbase.table.max.rowsize`*::
+
.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.

+
.Default
`1073741824`


[[hbase.thrift.minWorkerThreads]]
*`hbase.thrift.minWorkerThreads`*::
+
.Description
The "core size" of the thread pool. New threads are created on every
    connection until this many threads are created.
+
.Default
`16`


[[hbase.thrift.maxWorkerThreads]]
*`hbase.thrift.maxWorkerThreads`*::
+
.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.
+
.Default
`1000`


[[hbase.thrift.maxQueuedRequests]]
*`hbase.thrift.maxQueuedRequests`*::
+
.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.
+
.Default
`1000`


[[hbase.regionserver.thrift.framed]]
*`hbase.regionserver.thrift.framed`*::
+
.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.

+
.Default
`false`


[[hbase.regionserver.thrift.framed.max_frame_size_in_mb]]
*`hbase.regionserver.thrift.framed.max_frame_size_in_mb`*::
+
.Description
Default frame size when using framed transport
+
.Default
`2`


[[hbase.regionserver.thrift.compact]]
*`hbase.regionserver.thrift.compact`*::
+
.Description
Use Thrift TCompactProtocol binary serialization protocol.
+
.Default
`false`


[[hbase.data.umask.enable]]
*`hbase.data.umask.enable`*::
+
.Description
Enable, if true, that file permissions should be assigned
      to the files written by the regionserver
+
.Default
`false`


[[hbase.data.umask]]
*`hbase.data.umask`*::
+
.Description
File permissions that should be used to write data
      files when hbase.data.umask.enable is true
+
.Default
`000`


[[hbase.snapshot.enabled]]
*`hbase.snapshot.enabled`*::
+
.Description
Set to true to allow snapshots to be taken / restored / cloned.
+
.Default
`true`


[[hbase.snapshot.restore.take.failsafe.snapshot]]
*`hbase.snapshot.restore.take.failsafe.snapshot`*::
+
.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
+
.Default
`true`


[[hbase.snapshot.restore.failsafe.name]]
*`hbase.snapshot.restore.failsafe.name`*::
+
.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.
+
.Default
`hbase-failsafe-{snapshot.name}-{restore.timestamp}`


[[hbase.server.compactchecker.interval.multiplier]]
*`hbase.server.compactchecker.interval.multiplier`*::
+
.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.
+
.Default
`1000`


[[hbase.lease.recovery.timeout]]
*`hbase.lease.recovery.timeout`*::
+
.Description
How long we wait on dfs lease recovery in total before giving up.
+
.Default
`900000`


[[hbase.lease.recovery.dfs.timeout]]
*`hbase.lease.recovery.dfs.timeout`*::
+
.Description
How long between dfs recovery 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.
+
.Default
`64000`


[[hbase.column.max.version]]
*`hbase.column.max.version`*::
+
.Description
New column family descriptors will use this value as the default number of versions
      to keep.
+
.Default
`1`


[[hbase.dfs.client.read.shortcircuit.buffer.size]]
*`hbase.dfs.client.read.shortcircuit.buffer.size`*::
+
.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.

+
.Default
`131072`


[[hbase.regionserver.checksum.verify]]
*`hbase.regionserver.checksum.verify`*::
+
.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.

+
.Default
`true`


[[hbase.hstore.bytes.per.checksum]]
*`hbase.hstore.bytes.per.checksum`*::
+
.Description

        Number of bytes in a newly created checksum chunk for HBase-level
        checksums in hfile blocks.

+
.Default
`16384`


[[hbase.hstore.checksum.algorithm]]
*`hbase.hstore.checksum.algorithm`*::
+
.Description

      Name of an algorithm that is used to compute checksums. Possible values
      are NULL, CRC32, CRC32C.

+
.Default
`CRC32`


[[hbase.status.published]]
*`hbase.status.published`*::
+
.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.

+
.Default
`false`


[[hbase.status.publisher.class]]
*`hbase.status.publisher.class`*::
+
.Description

      Implementation of the status publication with a multicast message.

+
.Default
`org.apache.hadoop.hbase.master.ClusterStatusPublisher$MulticastPublisher`


[[hbase.status.listener.class]]
*`hbase.status.listener.class`*::
+
.Description

      Implementation of the status listener with a multicast message.

+
.Default
`org.apache.hadoop.hbase.client.ClusterStatusListener$MulticastListener`


[[hbase.status.multicast.address.ip]]
*`hbase.status.multicast.address.ip`*::
+
.Description

      Multicast address to use for the status publication by multicast.

+
.Default
`226.1.1.3`


[[hbase.status.multicast.address.port]]
*`hbase.status.multicast.address.port`*::
+
.Description

      Multicast port to use for the status publication by multicast.

+
.Default
`16100`


[[hbase.dynamic.jars.dir]]
*`hbase.dynamic.jars.dir`*::
+
.Description

      The directory from which the custom filter/co-processor 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.

+
.Default
`${hbase.rootdir}/lib`


[[hbase.security.authentication]]
*`hbase.security.authentication`*::
+
.Description

      Controls whether or not secure authentication is enabled for HBase.
      Possible values are 'simple' (no authentication), and 'kerberos'.

+
.Default
`simple`


[[hbase.rest.filter.classes]]
*`hbase.rest.filter.classes`*::
+
.Description

      Servlet filters for REST service.

+
.Default
`org.apache.hadoop.hbase.rest.filter.GzipFilter`


[[hbase.master.loadbalancer.class]]
*`hbase.master.loadbalancer.class`*::
+
.Description

      Class used to execute the regions balancing when the period occurs.
      See the class comment for more on how it works
      https://hbase.apache.org/devapidocs/org/apache/hadoop/hbase/master/balancer/StochasticLoadBalancer.html
      It replaces the DefaultLoadBalancer as the default (since renamed
      as the SimpleLoadBalancer).

+
.Default
`org.apache.hadoop.hbase.master.balancer.StochasticLoadBalancer`


[[hbase.security.exec.permission.checks]]
*`hbase.security.exec.permission.checks`*::
+
.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.

+
.Default
`false`


[[hbase.procedure.regionserver.classes]]
*`hbase.procedure.regionserver.classes`*::
+
.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.

+
.Default
``


[[hbase.procedure.master.classes]]
*`hbase.procedure.master.classes`*::
+
.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.
+
.Default
``

[[hbase.regionserver.storefile.refresh.period]]
*`hbase.regionserver.storefile.refresh.period`*::
+
.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.

+
.Default
`0`


[[hbase.region.replica.replication.enabled]]
*`hbase.region.replica.replication.enabled`*::
+
.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.


+
.Default
`false`


[[hbase.http.filter.initializers]]
*`hbase.http.filter.initializers`*::
+
.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 adds a user principal as defined by the
      hbase.http.staticuser.user property.

+
.Default
`org.apache.hadoop.hbase.http.lib.StaticUserWebFilter`


[[hbase.security.visibility.mutations.checkauths]]
*`hbase.security.visibility.mutations.checkauths`*::
+
.Description

      This property if enabled, will check whether the labels in the visibility expression are associated
      with the user issuing the mutation

+
.Default
`false`


[[hbase.http.max.threads]]
*`hbase.http.max.threads`*::
+
.Description

      The maximum number of threads that the HTTP Server will create in its
      ThreadPool.

+
.Default
`16`


[[hbase.replication.rpc.codec]]
*`hbase.replication.rpc.codec`*::
+
.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.

+
.Default
`org.apache.hadoop.hbase.codec.KeyValueCodecWithTags`


[[hbase.http.staticuser.user]]
*`hbase.http.staticuser.user`*::
+
.Description

      The user name to filter as on static web filters
      while rendering content. For example, the HDFS
      web UI (user to be used for browsing files).

+
.Default
`dr.stack`


[[hbase.regionserver.handler.abort.on.error.percent]]
*`hbase.regionserver.handler.abort.on.error.percent`*::
+
.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 handlers have died.
+
.Default
`0.5`


[[hbase.master.cleaner.snapshot.interval]]
*`hbase.master.cleaner.snapshot.interval`*::
+
.Description

    Snapshot Cleanup chore interval in milliseconds.
    The cleanup thread keeps running at this interval
    to find all snapshots that are expired based on TTL
    and delete them.

+
.Default
`1800000`


[[hbase.master.snapshot.ttl]]
*`hbase.master.snapshot.ttl`*::
+
.Description

      Default Snapshot TTL to be considered when the user
      does not specify TTL while creating snapshot.
      Default value 0 indicates FOREVERE - snapshot should not be
      automatically deleted until it is manually deleted


+
.Default
`0`


[[hbase.master.regions.recovery.check.interval]]
*`hbase.master.regions.recovery.check.interval`*::
+
.Description

    Regions Recovery Chore interval in milliseconds.
    This chore keeps running at this interval to
    find all regions with configurable max store file ref count
    and reopens them.

+
.Default
`1200000`


[[hbase.regions.recovery.store.file.ref.count]]
*`hbase.regions.recovery.store.file.ref.count`*::
+
.Description

      Very large number of ref count on a compacted
      store file indicates that it is a ref leak
      on that object(compacted store file).
      Such files can not be removed after
      it is invalidated via compaction.
      Only way to recover in such scenario is to
      reopen the region which can release
      all resources, like the refcount,
      leases, etc. This config represents Store files Ref
      Count threshold value considered for reopening
      regions. Any region with compacted store files
      ref count > this value would be eligible for
      reopening by master. Here, we get the max
      refCount among all refCounts on all
      compacted away store files that belong to a
      particular region. Default value -1 indicates
      this feature is turned off. Only positive
      integer value should be provided to
      enable this feature.

+
.Default
`-1`


[[hbase.regionserver.slowlog.ringbuffer.size]]
*`hbase.regionserver.slowlog.ringbuffer.size`*::
+
.Description

      Default size of ringbuffer to be maintained by each RegionServer in order
      to store online slowlog responses. This is an in-memory ring buffer of
      requests that were judged to be too slow in addition to the responseTooSlow
      logging. The in-memory representation would be complete.
      For more details, please look into Doc Section:
      <<slow_log_responses, slow_log_responses>>


+
.Default
`256`



[[hbase.regionserver.slowlog.buffer.enabled]]
*`hbase.regionserver.slowlog.buffer.enabled`*::
+
.Description

      Indicates whether RegionServers have ring buffer running for storing
      Online Slow logs in FIFO manner with limited entries. The size of
      the ring buffer is indicated by config: hbase.regionserver.slowlog.ringbuffer.size
      The default value is false, turn this on and get latest slowlog
      responses with complete data.
      For more details, please look into Doc Section:
      <<slow_log_responses, slow_log_responses>>


+
.Default
`false`


[[hbase.regionserver.slowlog.systable.enabled]]
*`hbase.regionserver.slowlog.systable.enabled`*::
+
.Description

      Should be enabled only if hbase.regionserver.slowlog.buffer.enabled is enabled.
      If enabled (true), all slow/large RPC logs would be persisted to system table
      hbase:slowlog (in addition to in-memory ring buffer at each RegionServer).
      The records are stored in increasing order of time.
      Operators can scan the table with various combination of ColumnValueFilter and
      time range.
      More details are provided in the doc section:
      "Get Slow/Large Response Logs from System table hbase:slowlog"

+
.Default
`false`


[[hbase.master.metafixer.max.merge.count]]
*`hbase.master.metafixer.max.merge.count`*::
+
.Description

      Maximum regions to merge at a time when we fix overlaps noted in
      CJ consistency report, but avoid merging 100 regions in one go!

+
.Default
`64`


[[hbase.rpc.rows.size.threshold.reject]]
*`hbase.rpc.rows.size.threshold.reject`*::
+
.Description

      If value is true, RegionServer will abort batch requests of
      Put/Delete with number of rows in a batch operation exceeding
      threshold defined by value of config:
      hbase.rpc.rows.warning.threshold.
      The default value is false and hence, by default, only
      warning will be logged. This config should be turned on to
      prevent RegionServer from serving
      very large batch size of rows and this way we can improve
      CPU usages by discarding too large batch request.

+
.Default
`false`

[[hbase.master.balancer.decision.buffer.enabled]]
*`hbase.master.balancer.decision.buffer.enabled`*::
+
.Description

      Indicates whether active HMaster has ring buffer running for storing
      balancer decisions in FIFO manner with limited entries. The size of
      the ring buffer is indicated by config:
      hbase.master.balancer.decision.queue.size

+
.Default
`false`

[[hbase.master.balancer.rejection.buffer.enabled]]
*`hbase.master.balancer.rejection.buffer.enabled`*::
+
.Description

      Indicates whether active HMaster has ring buffer running for storing
      balancer rejection in FIFO manner with limited entries. The size of
      the ring buffer is indicated by config:
      hbase.master.balancer.rejection.queue.size

+
.Default
`false`