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HBASE-11932 Docbook html-single build improvements

This commit is contained in:
Misty Stanley-Jones 2014-09-11 09:06:17 +10:00
parent eec15bd172
commit 2816487247
14 changed files with 151 additions and 211 deletions
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1
pom.xml
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@ -807,6 +807,7 @@
<phase>pre-site</phase>
<configuration>
<targetDirectory>${basedir}/target/docbkx/</targetDirectory>
<includes>book.xml</includes>
<preProcess>
<copy todir="target/docbkx/images">
<fileset dir="src/main/site/resources/images/"/>

28
src/main/docbkx/appendix_hfile_format.xml
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@ -31,18 +31,22 @@
<para>As we will be discussing changes to the HFile format, it is useful to give a short overview of the original (HFile version 1) format.</para>
<section xml:id="hfilev1.overview">
<title>Overview of Version 1</title>
<para>An HFile in version 1 format is structured as follows:
<inlinemediaobject>
<imageobject>
<imagedata align="center" valign="middle" fileref="hfile.png" />
</imageobject>
<textobject>
<phrase>HFile Version 1</phrase>
</textobject>
</inlinemediaobject>
<footnote><para>Image courtesy of Lars George, <link xlink:href="http://www.larsgeorge.com/2009/10/hbase-architecture-101-storage.html">hbase-architecture-101-storage.html</link>.</para></footnote>
</para>
<para>An HFile in version 1 format is structured as follows:</para>
<figure>
<title>HFile V1 Format</title>
<mediaobject>
<imageobject>
<imagedata align="center" valign="middle" fileref="hfile.png"/>
</imageobject>
<textobject>
<phrase>HFile Version 1</phrase>
</textobject>
<caption><para>Image courtesy of Lars George, <link
xlink:href="http://www.larsgeorge.com/2009/10/hbase-architecture-101-storage.html"
>hbase-architecture-101-storage.html</link>.</para></caption>
</mediaobject>
</figure>
</section>
<section><title> Block index format in version 1 </title>
<para>The block index in version 1 is very straightforward. For each entry, it contains: </para>

113
src/main/docbkx/book.xml
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@ -639,24 +639,19 @@ try {
store file, the most recent values are found first.</para>
<para>There is a lot of confusion over the semantics of <literal>cell</literal> versions, in
HBase. In particular, a couple questions that often come up are:</para>
HBase. In particular:</para>
<itemizedlist>
<listitem>
<para>If multiple writes to a cell have the same version, are all versions maintained or
just the last?<footnote>
<para>Currently, only the last written is fetchable.</para>
</footnote></para>
<para>If multiple writes to a cell have the same version, only the last written is
fetchable.</para>
</listitem>
<listitem>
<para>Is it OK to write cells in a non-increasing version order?<footnote>
<para>Yes</para>
</footnote></para>
<para>It is OK to write cells in a non-increasing version order.</para>
</listitem>
</itemizedlist>
<para>Below we describe how the version dimension in HBase currently works<footnote>
<para>See <link
<para>Below we describe how the version dimension in HBase currently works. See <link
xlink:href="https://issues.apache.org/jira/browse/HBASE-2406">HBASE-2406</link> for
discussion of HBase versions. <link
xlink:href="http://outerthought.org/blog/417-ot.html">Bending time in HBase</link>
@ -665,7 +660,6 @@ try {
<emphasis>Overwriting values at existing timestamps</emphasis> mentioned in the
article no longer holds in HBase. This section is basically a synopsis of this article
by Bruno Dumon.</para>
</footnote>.</para>
<section
xml:id="versions.ops">
@ -783,11 +777,10 @@ htable.put(put);
xml:id="version.delete">
<title>Delete</title>
<para>There are three different types of internal delete markers <footnote>
<para>See Lars Hofhansl's blog for discussion of his attempt adding another, <link
xlink:href="http://hadoop-hbase.blogspot.com/2012/01/scanning-in-hbase.html">Scanning
in HBase: Prefix Delete Marker</link></para>
</footnote>: </para>
<para>There are three different types of internal delete markers. See Lars Hofhansl's blog
for discussion of his attempt adding another, <link
xlink:href="http://hadoop-hbase.blogspot.com/2012/01/scanning-in-hbase.html">Scanning
in HBase: Prefix Delete Marker</link>. </para>
<itemizedlist>
<listitem>
<para>Delete: for a specific version of a column.</para>
@ -808,11 +801,10 @@ htable.put(put);
modifies data in place, so for example a delete will not immediately delete (or mark as
deleted) the entries in the storage file that correspond to the delete condition.
Rather, a so-called <emphasis>tombstone</emphasis> is written, which will mask the
deleted values<footnote>
<para>When HBase does a major compaction, the tombstones are processed to actually
remove the dead values, together with the tombstones themselves.</para>
</footnote>. If the version you specified when deleting a row is larger than the version
of any value in the row, then you can consider the complete row to be deleted.</para>
deleted values. When HBase does a major compaction, the tombstones are processed to
actually remove the dead values, together with the tombstones themselves. If the version
you specified when deleting a row is larger than the version of any value in the row,
then you can consider the complete row to be deleted.</para>
<para>For an informative discussion on how deletes and versioning interact, see the thread <link
xlink:href="http://comments.gmane.org/gmane.comp.java.hadoop.hbase.user/28421">Put w/
timestamp -> Deleteall -> Put w/ timestamp fails</link> up on the user mailing
@ -846,10 +838,8 @@ htable.put(put);
<title>Deletes mask Puts</title>
<para>Deletes mask puts, even puts that happened after the delete
was entered<footnote>
<para><link
xlink:href="https://issues.apache.org/jira/browse/HBASE-2256">HBASE-2256</link></para>
</footnote>. Remember that a delete writes a tombstone, which only
was entered. See <link xlink:href="https://issues.apache.org/jira/browse/HBASE-2256"
>HBASE-2256</link>. Remember that a delete writes a tombstone, which only
disappears after then next major compaction has run. Suppose you do
a delete of everything &lt;= T. After this you do a new put with a
timestamp &lt;= T. This put, even if it happened after the delete,
@ -868,14 +858,12 @@ htable.put(put);
<title>Major compactions change query results</title>
<para><quote>...create three cell versions at t1, t2 and t3, with a maximum-versions
setting of 2. So when getting all versions, only the values at t2 and t3 will be
returned. But if you delete the version at t2 or t3, the one at t1 will appear again.
Obviously, once a major compaction has run, such behavior will not be the case anymore...<footnote>
<para>See <emphasis>Garbage Collection</emphasis> in <link
xlink:href="http://outerthought.org/blog/417-ot.html">Bending time in
HBase</link>
</para>
</footnote></quote></para>
setting of 2. So when getting all versions, only the values at t2 and t3 will be
returned. But if you delete the version at t2 or t3, the one at t1 will appear again.
Obviously, once a major compaction has run, such behavior will not be the case
anymore...</quote> (See <emphasis>Garbage Collection</emphasis> in <link
xlink:href="http://outerthought.org/blog/417-ot.html">Bending time in
HBase</link>.)</para>
</section>
</section>
</section>
@ -2020,14 +2008,13 @@ rs.close();
</section> <!-- client.filter -->
<section xml:id="master"><title>Master</title>
<para><code>HMaster</code> is the implementation of the Master Server. The Master server
is responsible for monitoring all RegionServer instances in the cluster, and is
the interface for all metadata changes. In a distributed cluster, the Master typically runs on the <xref linkend="arch.hdfs.nn" /><footnote>
<para>J Mohamed Zahoor goes into some more detail on the Master Architecture in this blog posting, <link
xlink:href="http://blog.zahoor.in/2012/08/hbase-hmaster-architecture/">HBase HMaster Architecture
</link>.</para>
</footnote>
</para>
<para><code>HMaster</code> is the implementation of the Master Server. The Master server is
responsible for monitoring all RegionServer instances in the cluster, and is the interface
for all metadata changes. In a distributed cluster, the Master typically runs on the <xref
linkend="arch.hdfs.nn"/>. J Mohamed Zahoor goes into some more detail on the Master
Architecture in this blog posting, <link
xlink:href="http://blog.zahoor.in/2012/08/hbase-hmaster-architecture/">HBase HMaster
Architecture </link>.</para>
<section xml:id="master.startup"><title>Startup Behavior</title>
<para>If run in a multi-Master environment, all Masters compete to run the cluster. If the active
Master loses its lease in ZooKeeper (or the Master shuts down), then then the remaining Masters jostle to
@ -2469,17 +2456,16 @@ rs.close();
physical RAM, and is likely to be less than the total available RAM due to other
memory requirements and system constraints.
</para>
<para>You can see how much memory -- onheap and offheap/direct -- a RegionServer is configured to use
and how much it is using at any one time by looking at the
<emphasis>Server Metrics: Memory</emphasis> tab in the UI.
It can also be gotten via JMX. In particular the direct
memory currently used by the server can be found on the
<varname>java.nio.type=BufferPool,name=direct</varname>
bean.
<footnote><para>Terracotta has a <link xlink:href="http://terracotta.org/documentation/4.0/bigmemorygo/configuration/storage-options">good write up</link> on using offheap memory in java.
It is for their product BigMemory but alot of the issues noted apply
in general to any attempt at going offheap. Check it out.</para></footnote>
</para>
<para>You can see how much memory -- onheap and offheap/direct -- a RegionServer is
configured to use and how much it is using at any one time by looking at the
<emphasis>Server Metrics: Memory</emphasis> tab in the UI. It can also be gotten
via JMX. In particular the direct memory currently used by the server can be found
on the <varname>java.nio.type=BufferPool,name=direct</varname> bean. Terracotta has
a <link
xlink:href="http://terracotta.org/documentation/4.0/bigmemorygo/configuration/storage-options"
>good write up</link> on using offheap memory in java. It is for their product
BigMemory but alot of the issues noted apply in general to any attempt at going
offheap. Check it out.</para>
</note>
<note xml:id="hbase.bucketcache.percentage.in.combinedcache"><title>hbase.bucketcache.percentage.in.combinedcache</title>
<para>This is a pre-HBase 1.0 configuration removed because it
@ -2613,12 +2599,10 @@ rs.close();
</itemizedlist>
<para>If the <varname>hbase.hlog.split.skip.errors</varname> optionset to
<literal>false</literal>, the default, the exception will be propagated and the
split will be logged as failed.<footnote>
<para>See <link
split will be logged as failed. See <link
xlink:href="https://issues.apache.org/jira/browse/HBASE-2958">HBASE-2958 When
hbase.hlog.split.skip.errors is set to false, we fail the split but thats
it</link>. We need to do more than just fail split if this flag is set.</para>
</footnote></para>
<section>
<title>How EOFExceptions are treated when splitting a crashed RegionServers'
@ -2628,11 +2612,9 @@ rs.close();
<varname>hbase.hlog.split.skip.errors</varname> is set to
<literal>false</literal>. An EOFException while reading the last log in the set of
files to split is likely, because the RegionServer is likely to be in the process of
writing a record at the time of a crash. <footnote>
<para>For background, see <link
writing a record at the time of a crash. For background, see <link
xlink:href="https://issues.apache.org/jira/browse/HBASE-2643">HBASE-2643
Figure how to deal with eof splitting logs</link></para>
</footnote></para>
</section>
</section>
@ -3042,9 +3024,9 @@ ctime = Sat Jun 23 11:13:40 PDT 2012
</listitem>
<listitem><para>Third replica is written on the same rack as the second, but on a different node chosen randomly</para>
</listitem>
<listitem><para>Subsequent replicas are written on random nodes on the cluster
<footnote><para>See <emphasis>Replica Placement: The First Baby Steps</emphasis> on this page: <link xlink:href="http://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-hdfs/HdfsDesign.html">HDFS Architecture</link></para></footnote>
</para></listitem>
<listitem><para>Subsequent replicas are written on random nodes on the cluster. See <emphasis>Replica Placement: The First Baby Steps</emphasis> on this page: <link
xlink:href="http://hadoop.apache.org/docs/stable/hadoop-project-dist/hadoop-hdfs/HdfsDesign.html"
>HDFS Architecture</link></para></listitem>
</orderedlist>
<para>
Thus, HBase eventually achieves locality for a region after a flush or a compaction.
@ -5166,8 +5148,7 @@ This option should not normally be used, and it is not in <code>-fixAll</code>.
<imageobject>
<imagedata fileref="data_block_no_encoding.png" width="800"/>
</imageobject>
<textobject><para></para>
</textobject>
<caption><para>A ColumnFamily with no encoding></para></caption>
</mediaobject>
</figure>
<para>Here is the same data with prefix data encoding.</para>
@ -5177,8 +5158,7 @@ This option should not normally be used, and it is not in <code>-fixAll</code>.
<imageobject>
<imagedata fileref="data_block_prefix_encoding.png" width="800"/>
</imageobject>
<textobject><para></para>
</textobject>
<caption><para>A ColumnFamily with prefix encoding</para></caption>
</mediaobject>
</figure>
</listitem>
@ -5202,8 +5182,7 @@ This option should not normally be used, and it is not in <code>-fixAll</code>.
<imageobject>
<imagedata fileref="data_block_diff_encoding.png" width="800"/>
</imageobject>
<textobject><para></para>
</textobject>
<caption><para>A ColumnFamily with diff encoding</para></caption>
</mediaobject>
</figure>
</listitem>

5
src/main/docbkx/community.xml
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@ -40,12 +40,9 @@
committer will add it for you. Thereafter you can file issues against your feature branch in
Apache HBase JIRA. Your code you keep elsewhere -- it should be public so it can be observed
-- and you can update dev mailing list on progress. When the feature is ready for commit, 3
+1s from committers will get your feature merged<footnote>
<para>See <link
+1s from committers will get your feature merged. See <link
xlink:href="http://search-hadoop.com/m/asM982C5FkS1">HBase, mail # dev - Thoughts
about large feature dev branches</link></para>
</footnote>
</para>
</section>
<section
xml:id="patchplusonepolicy">

60
src/main/docbkx/configuration.xml
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@ -212,12 +212,10 @@
<term>DNS</term>
<listitem>
<para>HBase uses the local hostname to self-report its IP address. Both forward and
reverse DNS resolving must work in versions of HBase previous to 0.92.0.<footnote>
<para>The <link
reverse DNS resolving must work in versions of HBase previous to 0.92.0. The <link
xlink:href="https://github.com/sujee/hadoop-dns-checker">hadoop-dns-checker</link>
tool can be used to verify DNS is working correctly on the cluster. The project
README file provides detailed instructions on usage. </para>
</footnote></para>
<para>If your server has multiple network interfaces, HBase defaults to using the
interface that the primary hostname resolves to. To override this behavior, set the
@ -306,11 +304,10 @@
running the HBase process is an operating system configuration, rather than an HBase
configuration. It is also important to be sure that the settings are changed for the
user that actually runs HBase. To see which user started HBase, and that user's ulimit
configuration, look at the first line of the HBase log for that instance.<footnote>
<para>A useful read setting config on you hadoop cluster is Aaron Kimballs' <link
xlink:href="http://www.cloudera.com/blog/2009/03/configuration-parameters-what-can-you-just-ignore/">Configuration
Parameters: What can you just ignore?</link></para>
</footnote></para>
configuration, look at the first line of the HBase log for that instance. A useful read
setting config on you hadoop cluster is Aaron Kimballs' <link
xlink:href="http://www.cloudera.com/blog/2009/03/configuration-parameters-what-can-you-just-ignore/"
>Configuration Parameters: What can you just ignore?</link></para>
<formalpara xml:id="ulimit_ubuntu">
<title><command>ulimit</command> Settings on Ubuntu</title>
<para>To configure <command>ulimit</command> settings on Ubuntu, edit
@ -414,12 +411,8 @@ hadoop - nproc 32000
<entry>HBase-0.92.x</entry>
<entry>HBase-0.94.x</entry>
<entry>HBase-0.96.x</entry>
<entry>HBase-0.98.x<footnote>
<para>Support for Hadoop 1.x is deprecated.</para>
</footnote></entry>
<entry>HBase-1.0.x<footnote>
<para>Hadoop 1.x is NOT supported</para>
</footnote></entry>
<entry><para>HBase-0.98.x (Support for Hadoop 1.x is deprecated.)</para></entry>
<entry><para>HBase-1.0.x (Hadoop 1.x is NOT supported)</para></entry>
</row>
</thead>
<tbody>
@ -440,11 +433,9 @@ hadoop - nproc 32000
<entry>X</entry>
</row>
<row>
<entry>Hadoop-1.0.0-1.0.2<footnote>
<para>HBase requires hadoop 1.0.3 at a minimum; there is an issue where we cannot
find KerberosUtil compiling against earlier versions of Hadoop.</para>
</footnote>
</entry>
<entry><para>Hadoop-1.0.0-1.0.2 (HBase requires hadoop 1.0.3 at a minimum; there is an
issue where we cannot find KerberosUtil compiling against earlier versions of
Hadoop.)</para></entry>
<entry>X</entry>
<entry>X</entry>
<entry>X</entry>
@ -494,10 +485,9 @@ hadoop - nproc 32000
<row>
<entry>Hadoop-2.2.0 </entry>
<entry>X</entry>
<entry>NT <footnote>
<para>To get 0.94.x to run on hadoop 2.2.0, you need to change the hadoop 2 and
protobuf versions in the <filename>pom.xml</filename>: Here is a diff with
pom.xml changes: </para>
<entry><para>NT - To get 0.94.x to run on hadoop 2.2.0, you need to change the hadoop
2 and protobuf versions in the <filename>pom.xml</filename>: Here is a diff with
pom.xml changes: </para>
<programlisting><![CDATA[$ svn diff pom.xml
Index: pom.xml
===================================================================
@ -540,8 +530,7 @@ Index: pom.xml
</itemizedlist>
<para> Building against the hadoop 2 profile by running something like the
following command: </para>
<screen language="bourne">$ mvn clean install assembly:single -Dhadoop.profile=2.0 -DskipTests</screen>
</footnote></entry>
<screen language="bourne">$ mvn clean install assembly:single -Dhadoop.profile=2.0 -DskipTests</screen></entry>
<entry>S</entry>
<entry>S</entry>
<entry>NT</entry>
@ -601,11 +590,9 @@ Index: pom.xml
<para> As of Apache HBase 0.96.x, Apache Hadoop 1.0.x at least is required. Hadoop 2 is
strongly encouraged (faster but also has fixes that help MTTR). We will no longer run
properly on older Hadoops such as 0.20.205 or branch-0.20-append. Do not move to Apache
HBase 0.96.x if you cannot upgrade your Hadoop.<footnote>
<para>See <link
HBase 0.96.x if you cannot upgrade your Hadoop.. See <link
xlink:href="http://search-hadoop.com/m/7vFVx4EsUb2">HBase, mail # dev - DISCUSS:
Have hbase require at least hadoop 1.0.0 in hbase 0.96.0?</link></para>
</footnote></para>
</section>
<section
@ -615,13 +602,12 @@ Index: pom.xml
<code>sync</code> implementation. DO NOT use Hadoop 0.20.2, Hadoop 0.20.203.0, and
Hadoop 0.20.204.0 which DO NOT have this attribute. Currently only Hadoop versions
0.20.205.x or any release in excess of this version -- this includes hadoop-1.0.0 -- have
a working, durable sync <footnote>
<para>The Cloudera blog post <link
xlink:href="http://www.cloudera.com/blog/2012/01/an-update-on-apache-hadoop-1-0/">An
update on Apache Hadoop 1.0</link> by Charles Zedlweski has a nice exposition on how
all the Hadoop versions relate. Its worth checking out if you are having trouble
making sense of the Hadoop version morass. </para>
</footnote>. Sync has to be explicitly enabled by setting
a working, durable sync. The Cloudera blog post <link
xlink:href="http://www.cloudera.com/blog/2012/01/an-update-on-apache-hadoop-1-0/">An
update on Apache Hadoop 1.0</link> by Charles Zedlweski has a nice exposition on how all
the Hadoop versions relate. Its worth checking out if you are having trouble making sense
of the Hadoop version morass. </para>
<para>Sync has to be explicitly enabled by setting
<varname>dfs.support.append</varname> equal to true on both the client side -- in
<filename>hbase-site.xml</filename> -- and on the serverside in
<filename>hdfs-site.xml</filename> (The sync facility HBase needs is a subset of the
@ -713,9 +699,7 @@ Index: pom.xml
<para>Distributed mode can be subdivided into distributed but all daemons run on a single node
-- a.k.a <emphasis>pseudo-distributed</emphasis>-- and
<emphasis>fully-distributed</emphasis> where the daemons are spread across all nodes in
the cluster <footnote>
<para>The pseudo-distributed vs fully-distributed nomenclature comes from Hadoop.</para>
</footnote>.</para>
the cluster. The pseudo-distributed vs fully-distributed nomenclature comes from Hadoop.</para>
<para>Pseudo-distributed mode can run against the local filesystem or it can run against an
instance of the <emphasis>Hadoop Distributed File System</emphasis> (HDFS).

16
src/main/docbkx/cp.xml
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@ -29,16 +29,14 @@
*/
-->
<title>Apache HBase Coprocessors</title>
<para> HBase coprocessors are modeled after the coprocessors which are part of Google's BigTable<footnote>
<para><link
xlink:href="http://www.scribd.com/doc/21631448/Dean-Keynote-Ladis2009" />, pages
66-67.</para>
</footnote>. Coprocessors function in a similar way to Linux kernel modules. They provide a way
to run server-level code against locally-stored data. The functionality they provide is very
<para> HBase coprocessors are modeled after the coprocessors which are part of Google's BigTable
(<link xlink:href="http://www.scribd.com/doc/21631448/Dean-Keynote-Ladis2009"/>, pages
66-67.). Coprocessors function in a similar way to Linux kernel modules. They provide a way to
run server-level code against locally-stored data. The functionality they provide is very
powerful, but also carries great risk and can have adverse effects on the system, at the level
of the operating system. The information in this chapter is primarily sourced and heavily reused
from Mingjie Lai's blog post at <link
xlink:href="https://blogs.apache.org/hbase/entry/coprocessor_introduction" />. </para>
xlink:href="https://blogs.apache.org/hbase/entry/coprocessor_introduction"/>. </para>
<para> Coprocessors are not designed to be used by end users of HBase, but by HBase developers who
need to add specialized functionality to HBase. One example of the use of coprocessors is
@ -418,10 +416,10 @@ coprocessors=[AggregateImplementation]
<imageobject>
<imagedata fileref="coprocessor_stats.png" width="100%"/>
</imageobject>
<textobject>
<caption>
<para>The Coprocessor Metrics UI shows statistics about time spent executing a given
coprocessor, including min, max, average, and 90th, 95th, and 99th percentile.</para>
</textobject>
</caption>
</mediaobject>
</figure>
</section>

28
src/main/docbkx/ops_mgt.xml
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@ -757,11 +757,9 @@ false
<para>Without this facility, decommissioning mulitple nodes may be non-optimal because
regions that are being drained from one region server may be moved to other regionservers
that are also draining. Marking RegionServers to be in the draining state prevents this
from happening<footnote>
<para>See this <link
xlink:href="http://inchoate-clatter.blogspot.com/2012/03/hbase-ops-automation.html">blog
post</link> for more details.</para>
</footnote>. </para>
from happening. See this <link
xlink:href="http://inchoate-clatter.blogspot.com/2012/03/hbase-ops-automation.html">blog
post</link> for more details.</para>
</section>
<section
@ -1206,9 +1204,9 @@ $ for i in `cat conf/regionservers|sort`; do ./bin/graceful_stop.sh --restart --
<imageobject>
<imagedata fileref="bc_basic.png" width="100%"/>
</imageobject>
<textobject>
<caption>
<para>Shows the cache implementation</para>
</textobject>
</caption>
</mediaobject>
</figure>
<figure>
@ -1217,9 +1215,9 @@ $ for i in `cat conf/regionservers|sort`; do ./bin/graceful_stop.sh --restart --
<imageobject>
<imagedata fileref="bc_config.png" width="100%"/>
</imageobject>
<textobject>
<caption>
<para>Shows all cache configuration options.</para>
</textobject>
</caption>
</mediaobject>
</figure>
<figure>
@ -1228,9 +1226,9 @@ $ for i in `cat conf/regionservers|sort`; do ./bin/graceful_stop.sh --restart --
<imageobject>
<imagedata fileref="bc_stats.png" width="100%"/>
</imageobject>
<textobject>
<caption>
<para>Shows statistics about the performance of the cache.</para>
</textobject>
</caption>
</mediaobject>
</figure>
<figure>
@ -1242,9 +1240,9 @@ $ for i in `cat conf/regionservers|sort`; do ./bin/graceful_stop.sh --restart --
<imageobject>
<imagedata fileref="bc_l2_buckets.png" width="100%"/>
</imageobject>
<textobject>
<caption>
<para>Shows information about the L1 and L2 caches.</para>
</textobject>
</caption>
</mediaobject>
</figure>
<para>This is not an exhaustive list of all the screens and reports available. Have a look in
@ -1305,10 +1303,10 @@ $ for i in `cat conf/regionservers|sort`; do ./bin/graceful_stop.sh --restart --
<imageobject>
<imagedata fileref="replication_overview.png" />
</imageobject>
<textobject>
<caption>
<para>Illustration of the replication architecture in HBase, as described in the prior
text.</para>
</textobject>
</caption>
</mediaobject>
</figure>

63
src/main/docbkx/performance.xml
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@ -146,8 +146,7 @@
xml:id="gcpause">
<title>Long GC pauses</title>
<para
xml:id="mslab">In his presentation, <link
<para xml:id="mslab">In his presentation, <link
xlink:href="http://www.slideshare.net/cloudera/hbase-hug-presentation">Avoiding Full GCs
with MemStore-Local Allocation Buffers</link>, Todd Lipcon describes two cases of
stop-the-world garbage collections common in HBase, especially during loading; CMS failure
@ -158,16 +157,16 @@
Todd added an experimental facility, <indexterm><primary>MSLAB</primary></indexterm>, that
must be explicitly enabled in Apache HBase 0.90.x (Its defaulted to be on in Apache 0.92.x
HBase). See <code>hbase.hregion.memstore.mslab.enabled</code> to true in your
<classname>Configuration</classname>. See the cited slides for background and detail<footnote>
<para>The latest jvms do better regards fragmentation so make sure you are running a
recent release. Read down in the message, <link
xlink:href="http://osdir.com/ml/hotspot-gc-use/2011-11/msg00002.html">Identifying
concurrent mode failures caused by fragmentation</link>.</para>
</footnote>. Be aware that when enabled, each MemStore instance will occupy at least an
MSLAB instance of memory. If you have thousands of regions or lots of regions each with
many column families, this allocation of MSLAB may be responsible for a good portion of
your heap allocation and in an extreme case cause you to OOME. Disable MSLAB in this case,
or lower the amount of memory it uses or float less regions per server. </para>
<classname>Configuration</classname>. See the cited slides for background and detail.
The latest jvms do better regards fragmentation so make sure you are running a recent
release. Read down in the message, <link
xlink:href="http://osdir.com/ml/hotspot-gc-use/2011-11/msg00002.html">Identifying
concurrent mode failures caused by fragmentation</link>. Be aware that when enabled,
each MemStore instance will occupy at least an MSLAB instance of memory. If you have
thousands of regions or lots of regions each with many column families, this allocation of
MSLAB may be responsible for a good portion of your heap allocation and in an extreme case
cause you to OOME. Disable MSLAB in this case, or lower the amount of memory it uses or
float less regions per server. </para>
<para>If you have a write-heavy workload, check out <link
xlink:href="https://issues.apache.org/jira/browse/HBASE-8163">HBASE-8163
MemStoreChunkPool: An improvement for JAVA GC when using MSLAB</link>. It describes
@ -916,24 +915,20 @@ htable.close();
latencies.</para>
<para><link
xlink:href="http://en.wikipedia.org/wiki/Bloom_filter">Bloom filters</link> were developed
over in <link
xlink:href="https://issues.apache.org/jira/browse/HBASE-1200">HBase-1200 Add
bloomfilters</link>.<footnote>
<para>For description of the development process -- why static blooms rather than dynamic
over in <link xlink:href="https://issues.apache.org/jira/browse/HBASE-1200">HBase-1200 Add
bloomfilters</link>. For description of the development process -- why static blooms rather than dynamic
-- and for an overview of the unique properties that pertain to blooms in HBase, as well
as possible future directions, see the <emphasis>Development Process</emphasis> section
of the document <link
xlink:href="https://issues.apache.org/jira/secure/attachment/12444007/Bloom_Filters_in_HBase.pdf">BloomFilters
in HBase</link> attached to <link
xlink:href="https://issues.apache.org/jira/browse/HBASE-1200">HBase-1200</link>.</para>
</footnote><footnote>
<para>The bloom filters described here are actually version two of blooms in HBase. In
xlink:href="https://issues.apache.org/jira/browse/HBASE-1200">HBase-1200</link>. The bloom filters described here are actually version two of blooms in HBase. In
versions up to 0.19.x, HBase had a dynamic bloom option based on work done by the <link
xlink:href="http://www.one-lab.org">European Commission One-Lab Project 034819</link>.
The core of the HBase bloom work was later pulled up into Hadoop to implement
org.apache.hadoop.io.BloomMapFile. Version 1 of HBase blooms never worked that well.
Version 2 is a rewrite from scratch though again it starts with the one-lab work.</para>
</footnote></para>
<para>See also <xref
linkend="schema.bloom" />. </para>
@ -1047,11 +1042,9 @@ htable.close();
possible for the DFSClient to take a "short circuit" and read directly from the disk instead
of going through the DataNode when the data is local. What this means for HBase is that the
RegionServers can read directly off their machine's disks instead of having to open a socket
to talk to the DataNode, the former being generally much faster<footnote>
<para>See JD's <link
to talk to the DataNode, the former being generally much faster. See JD's <link
xlink:href="http://files.meetup.com/1350427/hug_ebay_jdcryans.pdf">Performance
Talk</link></para>
</footnote>. Also see <link
Talk</link>. Also see <link
xlink:href="http://search-hadoop.com/m/zV6dKrLCVh1">HBase, mail # dev - read short
circuit</link> thread for more discussion around short circuit reads. </para>
<para>To enable "short circuit" reads, it will depend on your version of Hadoop. The original
@ -1081,19 +1074,17 @@ htable.close();
</description>
</property>]]></programlisting>
<para>Be careful about permissions for the directory that hosts the shared domain socket;
dfsclient will complain if open to other than the hbase user. <footnote>
<para>If you are running on an old Hadoop, one that is without <link
xlink:href="https://issues.apache.org/jira/browse/HDFS-347">HDFS-347</link> but that
has <link
xlink:href="https://issues.apache.org/jira/browse/HDFS-2246">HDFS-2246</link>, you
must set two configurations. First, the hdfs-site.xml needs to be amended. Set the
property <varname>dfs.block.local-path-access.user</varname> to be the
<emphasis>only</emphasis> user that can use the shortcut. This has to be the user that
started HBase. Then in hbase-site.xml, set
<varname>dfs.client.read.shortcircuit</varname> to be <varname>true</varname>
</para>
</footnote>
dfsclient will complain if open to other than the hbase user. </para>
<para>If you are running on an old Hadoop, one that is without <link
xlink:href="https://issues.apache.org/jira/browse/HDFS-347">HDFS-347</link> but that has
<link xlink:href="https://issues.apache.org/jira/browse/HDFS-2246">HDFS-2246</link>, you
must set two configurations. First, the hdfs-site.xml needs to be amended. Set the property
<varname>dfs.block.local-path-access.user</varname> to be the <emphasis>only</emphasis>
user that can use the shortcut. This has to be the user that started HBase. Then in
hbase-site.xml, set <varname>dfs.client.read.shortcircuit</varname> to be
<varname>true</varname>
</para>
<para> Services -- at least the HBase RegionServers -- will need to be restarted in order to
pick up the new configurations. </para>
<note

2
src/main/docbkx/preface.xml
View File

@ -43,7 +43,7 @@
<title>About This Guide</title>
<para>This reference guide is a work in progress. The source for this guide can be found in
the <filename>src/main/docbkx</filename> directory of the HBase source. This reference
guide is marked up using <link xlink:href="http://www.docbook.com/">DocBook</link> from
guide is marked up using <link xlink:href="http://www.docbook.org/">DocBook</link> from
which the the finished guide is generated as part of the 'site' build target. Run
<programlisting language="bourne">mvn site</programlisting> to generate this documentation. Amendments and
improvements to the documentation are welcomed. Click <link

3
src/main/docbkx/rpc.xml
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@ -104,7 +104,8 @@
<section>
<title>&lt;preamble&gt;</title>
<para><programlisting>&lt;MAGIC 4 byte integer&gt; &lt;1 byte RPC Format Version&gt; &lt;1 byte auth type&gt;<footnote><para> We need the auth method spec. here so the connection header is encoded if auth enabled.</para></footnote></programlisting></para>
<programlisting>&lt;MAGIC 4 byte integer&gt; &lt;1 byte RPC Format Version&gt; &lt;1 byte auth type&gt;</programlisting>
<para> We need the auth method spec. here so the connection header is encoded if auth enabled.</para>
<para>E.g.: HBas0x000x50 -- 4 bytes of MAGIC -- ‘HBas’ -- plus one-byte of
version, 0 in this case, and one byte, 0x50 (SIMPLE). of an auth
type.</para>

8
src/main/docbkx/security.xml
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@ -32,11 +32,9 @@
<section
xml:id="hbase.secure.configuration">
<title>Secure Client Access to Apache HBase</title>
<para>Newer releases of Apache HBase (&gt;= 0.92) support optional SASL authentication of clients<footnote>
<para>See also Matteo Bertozzi's article on <link
<para>Newer releases of Apache HBase (&gt;= 0.92) support optional SASL authentication of clients. See also Matteo Bertozzi's article on <link
xlink:href="http://www.cloudera.com/blog/2012/09/understanding-user-authentication-and-authorization-in-apache-hbase/">Understanding
User Authentication and Authorization in Apache HBase</link>.</para>
</footnote>.</para>
<para>This describes how to set up Apache HBase and clients for connection to secure HBase
resources.</para>
@ -339,11 +337,9 @@ grant 'rest_server', 'RWCA'
<section
xml:id="hbase.secure.simpleconfiguration">
<title>Simple User Access to Apache HBase</title>
<para>Newer releases of Apache HBase (&gt;= 0.92) support optional SASL authentication of clients<footnote>
<para>See also Matteo Bertozzi's article on <link
<para>Newer releases of Apache HBase (&gt;= 0.92) support optional SASL authentication of clients. See also Matteo Bertozzi's article on <link
xlink:href="http://www.cloudera.com/blog/2012/09/understanding-user-authentication-and-authorization-in-apache-hbase/">Understanding
User Authentication and Authorization in Apache HBase</link>.</para>
</footnote>.</para>
<para>This describes how to set up Apache HBase and clients for simple user access to HBase
resources.</para>

23
src/main/docbkx/troubleshooting.xml
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@ -233,19 +233,16 @@ export SERVER_GC_OPTS="$SERVER_GC_OPTS -XX:NewSize=64m -XX:MaxNewSize=64m"
<section
xml:id="trouble.resources.lists">
<title>Mailing Lists</title>
<para>Ask a question on the <link
xlink:href="http://hbase.apache.org/mail-lists.html">Apache HBase mailing lists</link>.
The 'dev' mailing list is aimed at the community of developers actually building Apache
HBase and for features currently under development, and 'user' is generally used for
questions on released versions of Apache HBase. Before going to the mailing list, make sure
your question has not already been answered by searching the mailing list archives first.
Use <xref
linkend="trouble.resources.searchhadoop" />. Take some time crafting your question<footnote>
<para>See <link
xlink:href="http://www.mikeash.com/getting_answers.html">Getting Answers</link></para>
</footnote>; a quality question that includes all context and exhibits evidence the author
has tried to find answers in the manual and out on lists is more likely to get a prompt
response. </para>
<para>Ask a question on the <link xlink:href="http://hbase.apache.org/mail-lists.html">Apache
HBase mailing lists</link>. The 'dev' mailing list is aimed at the community of developers
actually building Apache HBase and for features currently under development, and 'user' is
generally used for questions on released versions of Apache HBase. Before going to the
mailing list, make sure your question has not already been answered by searching the mailing
list archives first. Use <xref linkend="trouble.resources.searchhadoop"/>. Take some time
crafting your question. See <link xlink:href="http://www.mikeash.com/getting_answers.html"
>Getting Answers</link> for ideas on crafting good questions. A quality question that
includes all context and exhibits evidence the author has tried to find answers in the
manual and out on lists is more likely to get a prompt response. </para>
</section>
<section
xml:id="trouble.resources.irc">

8
src/main/docbkx/upgrading.xml
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@ -71,12 +71,10 @@
out the jars of one version and replace them with the jars of another, compatible
version and all will just work. Unless otherwise specified, HBase point versions are
binary compatible. You can safely do rolling upgrades between binary compatible
versions; i.e. across point versions: e.g. from 0.94.5 to 0.94.6<footnote>
<para>See <link
versions; i.e. across point versions: e.g. from 0.94.5 to 0.94.6. See <link
xlink:href="http://search-hadoop.com/m/bOOvwHGW981/Does+compatibility+between+versions+also+mean+binary+compatibility%253F&amp;subj=Re+Does+compatibility+between+versions+also+mean+binary+compatibility+">Does
compatibility between versions also mean binary compatibility?</link>
discussion on the hbaes dev mailing list. </para>
</footnote>. </para>
</section>
<section
xml:id="hbase.rolling.restart">
@ -506,12 +504,10 @@ Successfully completed Log splitting
to change this (The 'normal'/default value is 64MB (67108864)). Run the script
<filename>bin/set_meta_memstore_size.rb</filename>. This will make the necessary
edit to your <varname>.META.</varname> schema. Failure to run this change will make for
a slow cluster <footnote>
<para> See <link
a slow cluster. See <link
xlink:href="https://issues.apache.org/jira/browse/HBASE-3499">HBASE-3499
Users upgrading to 0.90.0 need to have their .META. table updated with the
right MEMSTORE_SIZE</link>
</para>
</footnote> . </para>
</section>
</chapter>

4
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@ -52,12 +52,10 @@
<varname>hbase.zookeeper.property.clientPort</varname> property. For all default values used
by HBase, including ZooKeeper configuration, see <xref
linkend="hbase_default_configurations" />. Look for the
<varname>hbase.zookeeper.property</varname> prefix <footnote>
<para>For the full list of ZooKeeper configurations, see ZooKeeper's
<varname>hbase.zookeeper.property</varname> prefix. For the full list of ZooKeeper configurations, see ZooKeeper's
<filename>zoo.cfg</filename>. HBase does not ship with a <filename>zoo.cfg</filename> so
you will need to browse the <filename>conf</filename> directory in an appropriate ZooKeeper
download.</para>
</footnote></para>
<para>You must at least list the ensemble servers in <filename>hbase-site.xml</filename> using the
<varname>hbase.zookeeper.quorum</varname> property. This property defaults to a single