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From apurt...@apache.org
Subject [11/30] hbase git commit: HBASE-12918 Backport asciidoc changes (Enis Soztutar)
Date Wed, 28 Jan 2015 02:59:37 GMT
http://git-wip-us.apache.org/repos/asf/hbase/blob/7bf6c024/src/main/docbkx/case_studies.xml
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diff --git a/src/main/docbkx/case_studies.xml b/src/main/docbkx/case_studies.xml
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-<?xml version="1.0" encoding="UTF-8"?>
-<chapter version="5.0" xml:id="casestudies"
-         xmlns="http://docbook.org/ns/docbook"
-         xmlns:xlink="http://www.w3.org/1999/xlink"
-         xmlns:xi="http://www.w3.org/2001/XInclude"
-         xmlns:svg="http://www.w3.org/2000/svg"
-         xmlns:m="http://www.w3.org/1998/Math/MathML"
-         xmlns:html="http://www.w3.org/1999/xhtml"
-         xmlns:db="http://docbook.org/ns/docbook">
-<!--
-/**
- * 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
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
--->
-  <title>Apache HBase Case Studies</title>
-    <section xml:id="casestudies.overview">
-      <title>Overview</title>
-      <para>This chapter will describe a variety of performance and troubleshooting
case studies that can 
-      provide a useful blueprint on diagnosing Apache HBase cluster issues.</para>
-      <para>For more information on Performance and Troubleshooting, see <xref linkend="performance"/>
and <xref linkend="trouble"/>.
-      </para>
-    </section>
-
-    <section xml:id="casestudies.schema">
-    	<title>Schema Design</title>
-    	<para>See the schema design case studies here: <xref linkend="schema.casestudies"/>
-    	</para>
-		
-	</section>   <!--  schema design -->
-
-    <section xml:id="casestudies.perftroub">
-    	<title>Performance/Troubleshooting</title>
-   
-    <section xml:id="casestudies.slownode">
-      <title>Case Study #1 (Performance Issue On A Single Node)</title>
-      <section><title>Scenario</title>
-        <para>Following a scheduled reboot, one data node began exhibiting unusual
behavior.  Routine MapReduce 
-         jobs run against HBase tables which regularly completed in five or six minutes began
taking 30 or 40 minutes 
-         to finish. These jobs were consistently found to be waiting on map and reduce tasks
assigned to the troubled data node 
-         (e.g., the slow map tasks all had the same Input Split).           
-         The situation came to a head during a distributed copy, when the copy was severely
prolonged by the lagging node.
-		</para>
-       </section>
-      <section><title>Hardware</title>
-        <para>Datanodes:
-        <itemizedlist>
-          <listitem>Two 12-core processors</listitem>
-          <listitem>Six Enerprise SATA disks</listitem>
-          <listitem>24GB of RAM</listitem>
-          <listitem>Two bonded gigabit NICs</listitem>
-        </itemizedlist>
-        </para>		
-        <para>Network:
-        <itemizedlist>
-          <listitem>10 Gigabit top-of-rack switches</listitem>
-          <listitem>20 Gigabit bonded interconnects between racks.</listitem>
-        </itemizedlist>
-        </para>
-      </section>
-      <section><title>Hypotheses</title>
-		<section><title>HBase "Hot Spot" Region</title>
-		  <para>We hypothesized that we were experiencing a familiar point of pain: a "hot
spot" region in an HBase table, 
-		  where uneven key-space distribution can funnel a huge number of requests to a single
HBase region, bombarding the RegionServer 
-		  process and cause slow response time. Examination of the HBase Master status page showed
that the number of HBase requests to the 
-		  troubled node was almost zero.  Further, examination of the HBase logs showed that there
were no region splits, compactions, or other region transitions 
-		  in progress.  This effectively ruled out a "hot spot" as the root cause of the observed
slowness.
-          </para>		
-        </section>
-		<section><title>HBase Region With Non-Local Data</title>
-		  <para>Our next hypothesis was that one of the MapReduce tasks was requesting data
from HBase that was not local to the datanode, thus 
-		  forcing HDFS to request data blocks from other servers over the network.  Examination
of the datanode logs showed that there were very 
-		  few blocks being requested over the network, indicating that the HBase region was correctly
assigned, and that the majority of the necessary 
-		  data was located on the node. This ruled out the possibility of non-local data causing
a slowdown.
-          </para>
-        </section>		
-		<section><title>Excessive I/O Wait Due To Swapping Or An Over-Worked Or Failing
Hard Disk</title>
-          <para>After concluding that the Hadoop and HBase were not likely to be the
culprits, we moved on to troubleshooting the datanode's hardware. 
-          Java, by design, will periodically scan its entire memory space to do garbage collection.
 If system memory is heavily overcommitted, the Linux 
-          kernel may enter a vicious cycle, using up all of its resources swapping Java heap
back and forth from disk to RAM as Java tries to run garbage 
-          collection.  Further, a failing hard disk will often retry reads and/or writes
many times before giving up and returning an error. This can manifest 
-          as high iowait, as running processes wait for reads and writes to complete.  Finally,
a disk nearing the upper edge of its performance envelope will 
-          begin to cause iowait as it informs the kernel that it cannot accept any more data,
and the kernel queues incoming data into the dirty write pool in memory.  
-          However, using <code>vmstat(1)</code> and <code>free(1)</code>,
we could see that no swap was being used, and the amount of disk IO was only a few kilobytes
per second.
-          </para>		
-        </section>
-		<section><title>Slowness Due To High Processor Usage</title>
-          <para>Next, we checked to see whether the system was performing slowly simply
due to very high computational load.  <code>top(1)</code> showed that the system
load 
-          was higher than normal, but <code>vmstat(1)</code> and <code>mpstat(1)</code>
showed that the amount of processor being used for actual computation was low.
-          </para>	
-        </section>	
-		<section><title>Network Saturation (The Winner)</title>
-          <para>Since neither the disks nor the processors were being utilized heavily,
we moved on to the performance of the network interfaces.  The datanode had two 
-          gigabit ethernet adapters, bonded to form an active-standby interface.  <code>ifconfig(8)</code>
showed some unusual anomalies, namely interface errors, overruns, framing errors. 
-          While not unheard of, these kinds of errors are exceedingly rare on modern hardware
which is operating as it should:
-<programlisting>		
-$ /sbin/ifconfig bond0
-bond0  Link encap:Ethernet  HWaddr 00:00:00:00:00:00  
-inet addr:10.x.x.x  Bcast:10.x.x.255  Mask:255.255.255.0
-UP BROADCAST RUNNING MASTER MULTICAST  MTU:1500  Metric:1
-RX packets:2990700159 errors:12 dropped:0 overruns:1 frame:6          &lt;--- Look Here!
Errors!
-TX packets:3443518196 errors:0 dropped:0 overruns:0 carrier:0
-collisions:0 txqueuelen:0 
-RX bytes:2416328868676 (2.4 TB)  TX bytes:3464991094001 (3.4 TB)
-</programlisting>
-          </para>		
-          <para>These errors immediately lead us to suspect that one or more of the
ethernet interfaces might have negotiated the wrong line speed.  This was confirmed both by
running an ICMP ping 
-          from an external host and observing round-trip-time in excess of 700ms, and by
running <code>ethtool(8)</code> on the members of the bond interface and discovering
that the active interface 
-          was operating at 100Mbs/, full duplex.
-<programlisting>		
-$ sudo ethtool eth0
-Settings for eth0:
-Supported ports: [ TP ]
-Supported link modes:   10baseT/Half 10baseT/Full 
-                       100baseT/Half 100baseT/Full 
-                       1000baseT/Full 
-Supports auto-negotiation: Yes
-Advertised link modes:  10baseT/Half 10baseT/Full 
-                       100baseT/Half 100baseT/Full 
-                       1000baseT/Full 
-Advertised pause frame use: No
-Advertised auto-negotiation: Yes
-Link partner advertised link modes:  Not reported
-Link partner advertised pause frame use: No
-Link partner advertised auto-negotiation: No
-Speed: 100Mb/s                                     &lt;--- Look Here!  Should say 1000Mb/s!
-Duplex: Full
-Port: Twisted Pair
-PHYAD: 1
-Transceiver: internal
-Auto-negotiation: on
-MDI-X: Unknown
-Supports Wake-on: umbg
-Wake-on: g
-Current message level: 0x00000003 (3)
-Link detected: yes
-</programlisting>		
-		  </para>
-		  <para>In normal operation, the ICMP ping round trip time should be around 20ms,
and the interface speed and duplex should read, "1000MB/s", and, "Full", respectively.  
-		  </para>
-	    </section>
-     </section>  
-   	<section><title>Resolution</title>
-   	  <para>After determining that the active ethernet adapter was at the incorrect
speed, we used the <code>ifenslave(8)</code> command to make the standby interface

-   	  the active interface, which yielded an immediate improvement in MapReduce performance,
and a 10 times improvement in network throughput:
-	  </para>
-	  <para>On the next trip to the datacenter, we determined that the line speed issue
was ultimately caused by a bad network cable, which was replaced.
-	  </para>
-	</section>
-   </section>  <!--  case study -->
-    <section xml:id="casestudies.perf.1">
-      <title>Case Study #2 (Performance Research 2012)</title>
-      <para>Investigation results of a self-described "we're not sure what's wrong,
but it seems slow" problem. 
-      <link xlink:href="http://gbif.blogspot.com/2012/03/hbase-performance-evaluation-continued.html">http://gbif.blogspot.com/2012/03/hbase-performance-evaluation-continued.html</link>
-      </para>
-    </section>
-
-    <section xml:id="casestudies.perf.2">
-      <title>Case Study #3 (Performance Research 2010))</title>
-      <para>
-      Investigation results of general cluster performance from 2010.  Although this research
is on an older version of the codebase, this writeup
-      is still very useful in terms of approach.
-      <link xlink:href="http://hstack.org/hbase-performance-testing/">http://hstack.org/hbase-performance-testing/</link>
-      </para>
-    </section>
-
-    <section xml:id="casestudies.xceivers">
-      <title>Case Study #4 (xcievers Config)</title>
-      <para>Case study of configuring <code>xceivers</code>, and diagnosing
errors from mis-configurations.
-      <link xlink:href="http://www.larsgeorge.com/2012/03/hadoop-hbase-and-xceivers.html">http://www.larsgeorge.com/2012/03/hadoop-hbase-and-xceivers.html</link>
-      </para>
-      <para>See also <xref linkend="dfs.datanode.max.xcievers"/>.
-      </para>
-    </section>
-
-    </section>    <!--  performance/troubleshooting -->
-	
-  </chapter>

http://git-wip-us.apache.org/repos/asf/hbase/blob/7bf6c024/src/main/docbkx/community.xml
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diff --git a/src/main/docbkx/community.xml b/src/main/docbkx/community.xml
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@@ -1,140 +0,0 @@
-<?xml version="1.0"?>
-    <chapter xml:id="community"
-      version="5.0" xmlns="http://docbook.org/ns/docbook"
-      xmlns:xlink="http://www.w3.org/1999/xlink"
-      xmlns:xi="http://www.w3.org/2001/XInclude"
-      xmlns:svg="http://www.w3.org/2000/svg"
-      xmlns:m="http://www.w3.org/1998/Math/MathML"
-      xmlns:html="http://www.w3.org/1999/xhtml"
-      xmlns:db="http://docbook.org/ns/docbook">
-<!--
-/**
- * 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
- * "License"); you may not use this file except in compliance
- * with the License.  You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
--->
-    <title>Community</title>
-    <section xml:id="decisions">
-      <title>Decisions</title>
-      <section xml:id="feature_branches">
-        <title>Feature Branches</title>
-        <para>Feature Branches are easy to make.  You do not have to be a committer
to make one.  Just request the name of your branch be added to JIRA up on the
-        developer's mailing list and a 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 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">
-        <title>Patch +1 Policy</title>
-        <para>
-The below policy is something we put in place 09/2012.  It is a
-suggested policy rather than a hard requirement.  We want to try it
-first to see if it works before we cast it in stone.
-        </para>
-<para>
-Apache HBase is made of
-<link xlink:href="https://issues.apache.org/jira/browse/HBASE#selectedTab=com.atlassian.jira.plugin.system.project%3Acomponents-panel">components</link>.
-Components have one or more <xref linkend="OWNER" />s.  See the 'Description' field
on the
-<link xlink:href="https://issues.apache.org/jira/browse/HBASE#selectedTab=com.atlassian.jira.plugin.system.project%3Acomponents-panel">components</link>
-JIRA page for who the current owners are by component.
-</para>
-<para>
-Patches that fit within the scope of a single Apache HBase component require,
-at least, a +1 by one of the component's owners before commit. If
-owners are absent -- busy or otherwise -- two +1s by non-owners will
-suffice.
-</para>
-<para>
-Patches that span components need at least two +1s before they can be
-committed, preferably +1s by owners of components touched by the
-x-component patch (TODO: This needs tightening up but I think fine for
-first pass).
-</para>
-<para>
-Any -1 on a patch by anyone vetos a patch; it cannot be committed
-until the justification for the -1 is addressed.
-</para>
-      </section>
-      <section xml:id="hbase.fix.version.in.JIRA">
-          <title>How to set fix version in JIRA on issue resolve</title>
-          <para>Here is how <link xlink:href="http://search-hadoop.com/m/azemIi5RCJ1">we
agreed</link> to set versions in JIRA when we
-              resolve an issue.  If trunk is going to be 0.98.0 then:
-              <itemizedlist>
-                  <listitem><para>
-              Commit only to trunk: Mark with 0.98
-                </para></listitem>
-                  <listitem><para>
-              Commit to 0.95 and trunk : Mark with 0.98, and 0.95.x
-                </para></listitem>
-                  <listitem><para>
-              Commit to 0.94.x and 0.95, and trunk: Mark with 0.98, 0.95.x, and 0.94.x
-                </para></listitem>
-                  <listitem><para>
-              Commit to 89-fb: Mark with 89-fb.
-                </para></listitem>
-                  <listitem><para>
-              Commit site fixes: no version
-                </para></listitem>
-          </itemizedlist>
-          </para>
-      </section>
-      <section xml:id="hbase.when.to.close.JIRA">
-          <title>Policy on when to set a RESOLVED JIRA as CLOSED</title>
-          <para>We <link xlink:href="http://search-hadoop.com/m/4cIKs1iwXMS1">agreed</link>
-              that for issues that list multiple releases in their <emphasis>Fix Version/s</emphasis>
field,
-              CLOSE the issue on the release of any of the versions listed; subsequent change
-              to the issue must happen in a new JIRA.
-          </para>
-      </section>
-    </section>
-    <section xml:id="community.roles">
-      <title>Community Roles</title>
-      <section xml:id="OWNER">
-          <title>Component Owner/Lieutenant</title>
-        <para>
-Component owners are listed in the description field on this Apache HBase JIRA <link xlink:href="https://issues.apache.org/jira/browse/HBASE#selectedTab=com.atlassian.jira.plugin.system.project%3Acomponents-panel">components</link>
-page.  The owners are listed in the 'Description' field rather than in the 'Component
-Lead' field because the latter only allows us list one individual
-whereas it is encouraged that components have multiple owners.
-        </para>
-<para>
-Owners or component lieutenants are volunteers who are (usually, but not necessarily) expert
in
-their component domain and may have an agenda on how they think their
-Apache HBase component should evolve.
-</para>
-<para>
-Duties include:
-<orderedlist>
-<listitem>
-<para>
-Owners will try and review patches that land within their component's scope.
-</para>
-</listitem>
-<listitem>
-<para>
-If applicable, if an owner has an agenda, they will publish their
-goals or the design toward which they are driving their component
-</para>
-</listitem>
-</orderedlist>
-</para>
-<para>
-If you would like to be volunteer as a component owner, just write the
-dev list and we'll sign you up. Owners do not need to be committers.
-</para>
-      </section>
-    </section>
-    </chapter>


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