hbase/conf/hbase-default.xml

<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="configuration.xsl"?>
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<configuration>
  <property>
    <name>hbase.rootdir</name>
    <value>file:///tmp/hbase-${user.name}/hbase</value>
    <description>The directory shared by region servers.
    Should be fully-qualified to include the filesystem to use.
    E.g: hdfs://NAMENODE_SERVER:PORT/HBASE_ROOTDIR
    </description>
  </property>
  <property>
    <name>hbase.master</name>
    <value>local</value>
    <description>The host and port that the HBase master runs at.
    A value of 'local' runs the master and a regionserver in
    a single process.
    </description>
  </property>
  <property>
    <name>hbase.master.info.port</name>
    <value>60010</value>
    <description>The port for the hbase master web UI
    Set to -1 if you do not want the info server to run.
    </description>
  </property>
  <property>
    <name>hbase.master.info.bindAddress</name>
    <value>0.0.0.0</value>
    <description>The address for the hbase master web UI
    </description>
  </property>
  <property>
    <name>hbase.master.meta.thread.rescanfrequency</name>
    <value>60000</value>
    <description>How long the HMaster sleeps (in milliseconds) between scans of
    the root and meta tables.
    </description>
  </property>
  <property>
    <name>hbase.master.lease.period</name>
    <value>120000</value>
    <description>HMaster server lease period in milliseconds. Default is
    120 seconds.  Region servers must report in within this period else
    they are considered dead.  On loaded cluster, may need to up this
    period.</description>
  </property>
  <property>
    <name>hbase.regionserver</name>
    <value>0.0.0.0:60020</value>
    <description>The host and port a HBase region server runs at.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.dns.interface</name>
    <value>default</value>
    <description>Name of the network interface which a regionserver
    should use to determine it's "real" IP address.  This lookup
    prevents strings like "localhost" and "127.0.0.1" from being
    reported back to the master.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.info.port</name>
    <value>60030</value>
    <description>The port for the hbase regionserver web UI
    Set to -1 if you do not want the info server 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.class</name>
    <value>org.apache.hadoop.hbase.ipc.HRegionInterface</value>
    <description>An interface that is assignable to HRegionInterface.  Used in HClient for
    opening proxy to remote region server.
    </description>
  </property>
  <property>
    <name>hbase.client.pause</name>
    <value>2000</value>
    <description>General client pause value.  Used mostly as value to wait
    before running a retry of a failed get, region lookup, etc.</description>
  </property>
  <property>
    <name>hbase.client.retries.number</name>
    <value>10</value>
    <description>Maximum retries.  Used as maximum for all retryable
    operations such as fetching of the root region from root region
    server, getting a cell's value, starting a row update, etc.
    Default: 10.
    </description>
  </property>
  <property>
    <name>hbase.client.scanner.caching</name>
    <value>30</value>
    <description>Number of rows that will be fetched when calling next
    on a scanner if it is not served from 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.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.lease.period</name>
    <value>60000</value>
    <description>HRegion server lease period in milliseconds. Default is
    60 seconds. Clients must report in within this period else they are
    considered dead.</description>
  </property>
  <property>
    <name>hbase.regionserver.handler.count</name>
    <value>10</value>
    <description>Count of RPC Server instances spun up on RegionServers
    Same property is used by the HMaster for count of master handlers.
    Default is 10.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.msginterval</name>
    <value>3000</value>
    <description>Interval between messages from the RegionServer to HMaster
    in milliseconds.  Default is 3 seconds.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.maxlogentries</name>
    <value>30000</value>
    <description>Rotate the HRegion HLogs when count of entries exceeds this
    value.  Default: 30,000.  Value is checked by a thread that runs every
    hbase.server.thread.wakefrequency.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.optionalcacheflushinterval</name>
    <value>1800000</value>
    <description>
    Amount of time to wait since the last time a region was flushed before
    invoking an optional cache flush (An optional cache flush is a
    flush even though memcache is not at the memcache.flush.size).
    Default: 30 minutes (in miliseconds)
    </description>
  </property>
  <property>
    <name>hbase.regionserver.optionallogrollinterval</name>
    <value>1800000</value>
    <description>
    Amount of time to wait since the last time a the region server's log was
    rolled before invoking an optional log roll (An optional log roll is a
    one in which the log does not contain hbase.regionserver.maxlogentries).
    Default: 30 minutes (in miliseconds)
    </description>
  </property>
  <property>
    <name>hbase.regionserver.thread.splitcompactcheckfrequency</name>
    <value>20000</value>
    <description>How often a region server runs the split/compaction check.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.nbreservationblocks</name>
    <value>4</value>
    <description>The number of reservation blocks which are used to prevent
    unstable region servers caused by an OOME.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.globalMemcacheLimit</name>
    <value>536870912</value>
    <description>Maximum size of all memcaches in a region server before new 
      updates are blocked and flushes are forced. Defaults to 512MB.
    </description>
  </property>
  <property>
    <name>hbase.regionserver.globalMemcacheLimitlowMark</name>
    <value>256435456</value>
    <description>When memcaches are being forced to flush to make room in
      memory, keep flushing until we hit this mark. Defaults to 256MB. Setting
      this value equal to hbase.regionserver.globalmemcachelimit causes the 
      minimum possible flushing to occur when updates are blocked due to 
      memcache limiting.
    </description>
  </property>  
  <property>
    <name>hbase.hbasemaster.maxregionopen</name>
    <value>120000</value>
    <description>Period to wait for a region open.  If regionserver
    takes longer than this interval, assign to a new regionserver.
    </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 META scanner and log roller.
    </description>
  </property>
  <property>
    <name>hbase.hregion.memcache.flush.size</name>
    <value>67108864</value>
    <description>
    A HRegion memcache will be flushed to disk if size of the memcache
    exceeds this number of bytes.  Value is checked by a thread that runs
    every hbase.server.thread.wakefrequency.  
    </description>
  </property>
  <property>
    <name>hbase.hregion.memcache.block.multiplier</name>
    <value>2</value>
    <description>
    Block updates if memcache has hbase.hregion.block.memcache
    time hbase.hregion.flush.size bytes.  Useful preventing
    runaway memcache during spikes in update traffic.  Without an
    upper-bound, memcache 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.max.filesize</name>
    <value>268435456</value>
    <description>
    Maximum HStoreFile size. If any one of a column families' HStoreFiles has
    grown to exceed this value, the hosting HRegion is split in two.
    Default: 256M.
    </description>
  </property>
  <property>
    <name>hbase.hstore.compactionThreshold</name>
    <value>3</value>
    <description>
    If more than this number of HStoreFiles in any one HStore
    (one HStoreFile is written per flush of memcache) then a compaction
    is run to rewrite all HStoreFiles files as one.  Larger numbers
    put off compaction but when it runs, it takes longer to complete.
    During a compaction, updates cannot be flushed to disk.  Long
    compactions require memory sufficient to carry the logging of
    all updates across the duration of the compaction.
    
    If too large, clients timeout during compaction.
    </description>
  </property>
  <property>
    <name>hbase.hstore.compaction.max</name>
    <value>10</value>
    <description>Max number of HStoreFiles to compact per 'minor' compaction.
    </description>
  </property>
  <property>
    <name>hbase.hregion.majorcompaction</name>
    <value>86400000</value>
    <description>The time (in miliseconds) between 'major' compactions of all
    HStoreFiles in a region.  Default: 1 day.
    </description>
  </property>
  <property>
    <name>hbase.regions.slop</name>
    <value>0.1</value>
    <description>Rebalance if regionserver has average + (average * slop) regions.
    Default is 10% slop.
    </description>
  </property>
  <property>
    <name>hbase.io.index.interval</name>
    <value>32</value>
    <description>The interval at which we record offsets in hbase
    store files/mapfiles.  Default for stock mapfiles is 128.  Index
    files are read into memory.  If there are many of them, could prove
    a burden.  If so play with the hadoop io.map.index.skip property and
    skip every nth index member when reading back the index into memory.
    </description>
  </property>
  <property>
    <name>hbase.io.seqfile.compression.type</name>
    <value>NONE</value>
    <description>The compression type for hbase sequencefile.Writers
    such as hlog.
    </description>
  </property>
  <property>
    <name>hbase.hstore.blockCache.blockSize</name>
    <value>65536</value>
    <description>The size of each block in any block caches.
    </description>
  </property>
  <property>
    <name>hbase.hash.type</name>
    <value>murmur</value>
    <description>The hashing algorithm for use in HashFunction. Two values are
    supported now: murmur (MurmurHash) and jenkins (JenkinsHash).
    </description>
  </property>
</configuration>