Apache
/
hbase
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

HBASE-3831 docbook xml files - standardized RegionServer, DataNode, and ZooKeeper in several xml docs 

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1098158 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Michael Stack 2011-04-30 21:05:39 +00:00
parent 94bd6f7710
commit e85e7ad354
5 changed files with 51 additions and 51 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
src/docbkx/book.xml
View File

@ -231,7 +231,7 @@ throws InterruptedException, IOException {
</para> </para>
</section> </section>
<section xml:id="rs_metrics"> <section xml:id="rs_metrics">
<title>Region Server Metrics</title> <title>RegionServer Metrics</title>
<section xml:id="hbase.regionserver.blockCacheCount"><title><varname>hbase.regionserver.blockCacheCount</varname></title> <section xml:id="hbase.regionserver.blockCacheCount"><title><varname>hbase.regionserver.blockCacheCount</varname></title>
<para>Block cache item count in memory. This is the number of blocks of storefiles (HFiles) in the cache.</para> <para>Block cache item count in memory. This is the number of blocks of storefiles (HFiles) in the cache.</para>
</section> </section>
@ -266,22 +266,22 @@ throws InterruptedException, IOException {
<para>TODO</para> <para>TODO</para>
</section> </section>
<section xml:id="hbase.regionserver.memstoreSizeMB"><title><varname>hbase.regionserver.memstoreSizeMB</varname></title> <section xml:id="hbase.regionserver.memstoreSizeMB"><title><varname>hbase.regionserver.memstoreSizeMB</varname></title>
<para>Sum of all the memstore sizes in this regionserver (MB)</para> <para>Sum of all the memstore sizes in this RegionServer (MB)</para>
</section> </section>
<section xml:id="hbase.regionserver.regions"><title><varname>hbase.regionserver.regions</varname></title> <section xml:id="hbase.regionserver.regions"><title><varname>hbase.regionserver.regions</varname></title>
<para>Number of regions served by the regionserver</para> <para>Number of regions served by the RegionServer</para>
</section> </section>
<section xml:id="hbase.regionserver.requests"><title><varname>hbase.regionserver.requests</varname></title> <section xml:id="hbase.regionserver.requests"><title><varname>hbase.regionserver.requests</varname></title>
<para>Total number of read and write requests. Requests correspond to regionserver RPC calls, thus a single Get will result in 1 request, but a Scan with caching set to 1000 will result in 1 request for each 'next' call (i.e., not each row). A bulk-load request will constitute 1 request per HFile.</para> <para>Total number of read and write requests. Requests correspond to RegionServer RPC calls, thus a single Get will result in 1 request, but a Scan with caching set to 1000 will result in 1 request for each 'next' call (i.e., not each row). A bulk-load request will constitute 1 request per HFile.</para>
</section> </section>
<section xml:id="hbase.regionserver.storeFileIndexSizeMB"><title><varname>hbase.regionserver.storeFileIndexSizeMB</varname></title> <section xml:id="hbase.regionserver.storeFileIndexSizeMB"><title><varname>hbase.regionserver.storeFileIndexSizeMB</varname></title>
<para>Sum of all the storefile index sizes in this regionserver (MB)</para> <para>Sum of all the storefile index sizes in this RegionServer (MB)</para>
</section> </section>
<section xml:id="hbase.regionserver.stores"><title><varname>hbase.regionserver.stores</varname></title> <section xml:id="hbase.regionserver.stores"><title><varname>hbase.regionserver.stores</varname></title>
<para>Number of stores open on the regionserver. A store corresponds to a column family. For example, if a table (which contains the column family) has 3 regions on a regionserver, there will be 3 stores open for that column family. </para> <para>Number of stores open on the RegionServer. A store corresponds to a column family. For example, if a table (which contains the column family) has 3 regions on a RegionServer, there will be 3 stores open for that column family. </para>
</section> </section>
<section xml:id="hbase.regionserver.storeFiles"><title><varname>hbase.regionserver.storeFiles</varname></title> <section xml:id="hbase.regionserver.storeFiles"><title><varname>hbase.regionserver.storeFiles</varname></title>
<para>Number of store filles open on the regionserver. A store may have more than one storefile (HFile).</para> <para>Number of store filles open on the RegionServer. A store may have more than one storefile (HFile).</para>
</section> </section>
</section> </section>
</chapter> </chapter>
@ -712,7 +712,7 @@ throws InterruptedException, IOException {
</para> </para>
<para><link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html">HTable</link> <para><link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html">HTable</link>
instances are not thread-safe. When creating HTable instances, it is advisable to use the same <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/HBaseConfiguration">HBaseConfiguration</link> instances are not thread-safe. When creating HTable instances, it is advisable to use the same <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/HBaseConfiguration">HBaseConfiguration</link>
instance. This will ensure sharing of zookeeper and socket instances to the region servers instance. This will ensure sharing of ZooKeeper and socket instances to the RegionServers
which is usually what you want. For example, this is preferred: which is usually what you want. For example, this is preferred:
<programlisting>HBaseConfiguration conf = HBaseConfiguration.create(); <programlisting>HBaseConfiguration conf = HBaseConfiguration.create();
HTable table1 = new HTable(conf, "myTable"); HTable table1 = new HTable(conf, "myTable");
@ -729,7 +729,7 @@ HTable table2 = new HTable(conf2, "myTable");</programlisting>
<section xml:id="client.writebuffer"><title>WriteBuffer and Batch Methods</title> <section xml:id="client.writebuffer"><title>WriteBuffer and Batch Methods</title>
<para>If <xref linkend="perf.hbase.client.autoflush" /> is turned off on <para>If <xref linkend="perf.hbase.client.autoflush" /> is turned off on
<link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html">HTable</link>, <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html">HTable</link>,
<classname>Put</classname>s are sent to region servers when the writebuffer <classname>Put</classname>s are sent to RegionServers when the writebuffer
is filled. The writebuffer is 2MB by default. Before an HTable instance is is filled. The writebuffer is 2MB by default. Before an HTable instance is
discarded, either <methodname>close()</methodname> or discarded, either <methodname>close()</methodname> or
<methodname>flushCommits()</methodname> should be invoked so Puts <methodname>flushCommits()</methodname> should be invoked so Puts
@ -742,7 +742,7 @@ HTable table2 = new HTable(conf2, "myTable");</programlisting>
</section> </section>
<section xml:id="client.filter"><title>Filters</title> <section xml:id="client.filter"><title>Filters</title>
<para><link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Get.html">Get</link> and <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Scan.html">Scan</link> instances can be <para><link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Get.html">Get</link> and <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Scan.html">Scan</link> instances can be
optionally configured with <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/filter/Filter.html">filters</link> which are applied on the region server. optionally configured with <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/filter/Filter.html">filters</link> which are applied on the RegionServer.
</para> </para>
</section> </section>
</section> </section>
@ -796,7 +796,7 @@ HTable table2 = new HTable(conf2, "myTable");</programlisting>
<listitem> <listitem>
<para>There is not much memory footprint difference between 1 region <para>There is not much memory footprint difference between 1 region
and 10 in terms of indexes, etc, held by the regionserver.</para> and 10 in terms of indexes, etc, held by the RegionServer.</para>
</listitem> </listitem>
</itemizedlist> </itemizedlist>
@ -1118,27 +1118,27 @@ HTable table2 = new HTable(conf2, "myTable");</programlisting>
<para>See <xref linkend="compression.tool" />.</para> <para>See <xref linkend="compression.tool" />.</para>
</section> </section>
<section xml:id="decommission"><title>Node Decommission</title> <section xml:id="decommission"><title>Node Decommission</title>
<para>You can stop an individual regionserver by running the following <para>You can stop an individual RegionServer by running the following
script in the HBase directory on the particular node: script in the HBase directory on the particular node:
<programlisting>$ ./bin/hbase-daemon.sh stop regionserver</programlisting> <programlisting>$ ./bin/hbase-daemon.sh stop regionserver</programlisting>
The regionserver will first close all regions and then shut itself down. The RegionServer will first close all regions and then shut itself down.
On shutdown, the regionserver's ephemeral node in ZooKeeper will expire. On shutdown, the RegionServer's ephemeral node in ZooKeeper will expire.
The master will notice the regionserver gone and will treat it as The master will notice the RegionServer gone and will treat it as
a 'crashed' server; it will reassign the nodes the regionserver was carrying. a 'crashed' server; it will reassign the nodes the RegionServer was carrying.
<note><title>Disable the Load Balancer before Decommissioning a node</title> <note><title>Disable the Load Balancer before Decommissioning a node</title>
<para>If the load balancer runs while a node is shutting down, then <para>If the load balancer runs while a node is shutting down, then
there could be contention between the Load Balancer and the there could be contention between the Load Balancer and the
Master's recovery of the just decommissioned regionserver. Master's recovery of the just decommissioned RegionServer.
Avoid any problems by disabling the balancer first. Avoid any problems by disabling the balancer first.
See <xref linkend="lb" /> below. See <xref linkend="lb" /> below.
</para> </para>
</note> </note>
</para> </para>
<para> <para>
A downside to the above stop of a regionserver is that regions could be offline for A downside to the above stop of a RegionServer is that regions could be offline for
a good period of time. Regions are closed in order. If many regions on the server, the a good period of time. Regions are closed in order. If many regions on the server, the
first region to close may not be back online until all regions close and after the master first region to close may not be back online until all regions close and after the master
notices the regionserver's znode gone. In HBase 0.90.2, we added facility for having notices the RegionServer's znode gone. In HBase 0.90.2, we added facility for having
a node gradually shed its load and then shutdown itself down. HBase 0.90.2 added the a node gradually shed its load and then shutdown itself down. HBase 0.90.2 added the
<filename>graceful_stop.sh</filename> script. Here is its usage: <filename>graceful_stop.sh</filename> script. Here is its usage:
<programlisting>$ ./bin/graceful_stop.sh <programlisting>$ ./bin/graceful_stop.sh
@ -1151,14 +1151,14 @@ Usage: graceful_stop.sh [--config &amp;conf-dir>] [--restart] [--reload] [--thri
hostname Hostname of server we are to stop</programlisting> hostname Hostname of server we are to stop</programlisting>
</para> </para>
<para> <para>
To decommission a loaded regionserver, run the following: To decommission a loaded RegionServer, run the following:
<programlisting>$ ./bin/graceful_stop.sh HOSTNAME</programlisting> <programlisting>$ ./bin/graceful_stop.sh HOSTNAME</programlisting>
where <varname>HOSTNAME</varname> is the host carrying the RegionServer where <varname>HOSTNAME</varname> is the host carrying the RegionServer
you would decommission. you would decommission.
<note><title>On <varname>HOSTNAME</varname></title> <note><title>On <varname>HOSTNAME</varname></title>
<para>The <varname>HOSTNAME</varname> passed to <filename>graceful_stop.sh</filename> <para>The <varname>HOSTNAME</varname> passed to <filename>graceful_stop.sh</filename>
must match the hostname that hbase is using to identify regionservers. must match the hostname that hbase is using to identify RegionServers.
Check the list of regionservers in the master UI for how HBase is Check the list of RegionServers in the master UI for how HBase is
referring to servers. Its usually hostname but can also be FQDN. referring to servers. Its usually hostname but can also be FQDN.
Whatever HBase is using, this is what you should pass the Whatever HBase is using, this is what you should pass the
<filename>graceful_stop.sh</filename> decommission <filename>graceful_stop.sh</filename> decommission
@ -1167,7 +1167,7 @@ Usage: graceful_stop.sh [--config &amp;conf-dir>] [--restart] [--reload] [--thri
currently running; the graceful unloading of regions will not run. currently running; the graceful unloading of regions will not run.
</para> </para>
</note> The <filename>graceful_stop.sh</filename> script will move the regions off the </note> The <filename>graceful_stop.sh</filename> script will move the regions off the
decommissioned regionserver one at a time to minimize region churn. decommissioned RegionServer one at a time to minimize region churn.
It will verify the region deployed in the new location before it It will verify the region deployed in the new location before it
will moves the next region and so on until the decommissioned server will moves the next region and so on until the decommissioned server
is carrying zero regions. At this point, the <filename>graceful_stop.sh</filename> is carrying zero regions. At this point, the <filename>graceful_stop.sh</filename>
@ -1201,7 +1201,7 @@ false
<programlisting>$ for i in `cat conf/regionservers|sort`; do ./bin/graceful_stop.sh --restart --reload --debug $i; done &amp;> /tmp/log.txt &amp; <programlisting>$ for i in `cat conf/regionservers|sort`; do ./bin/graceful_stop.sh --restart --reload --debug $i; done &amp;> /tmp/log.txt &amp;
</programlisting> </programlisting>
Tail the output of <filename>/tmp/log.txt</filename> to follow the scripts Tail the output of <filename>/tmp/log.txt</filename> to follow the scripts
progress. The above does regionservers only. Be sure to disable the progress. The above does RegionServers only. Be sure to disable the
load balancer before doing the above. You'd need to do the master load balancer before doing the above. You'd need to do the master
update separately. Do it before you run the above script. update separately. Do it before you run the above script.
Here is a pseudo-script for how you might craft a rolling restart script: Here is a pseudo-script for how you might craft a rolling restart script:
@ -1227,10 +1227,10 @@ false
</para> </para>
</listitem> </listitem>
<listitem> <listitem>
<para>Run the <filename>graceful_stop.sh</filename> script per regionserver. For example: <para>Run the <filename>graceful_stop.sh</filename> script per RegionServer. For example:
<programlisting>$ for i in `cat conf/regionservers|sort`; do ./bin/graceful_stop.sh --restart --reload --debug $i; done &amp;> /tmp/log.txt &amp; <programlisting>$ for i in `cat conf/regionservers|sort`; do ./bin/graceful_stop.sh --restart --reload --debug $i; done &amp;> /tmp/log.txt &amp;
</programlisting> </programlisting>
If you are running thrift or rest servers on the regionserver, pass --thrift or --rest options (See usage If you are running thrift or rest servers on the RegionServer, pass --thrift or --rest options (See usage
for <filename>graceful_stop.sh</filename> script). for <filename>graceful_stop.sh</filename> script).
</para> </para>
</listitem> </listitem>

6
src/docbkx/configuration.xml
View File

@ -114,7 +114,7 @@ to ensure well-formedness of your document after an edit session.
a minute or even less so the Master notices failures the sooner. a minute or even less so the Master notices failures the sooner.
Before changing this value, be sure you have your JVM garbage collection Before changing this value, be sure you have your JVM garbage collection
configuration under control otherwise, a long garbage collection that lasts configuration under control otherwise, a long garbage collection that lasts
beyond the zookeeper session timeout will take out beyond the ZooKeeper session timeout will take out
your RegionServer (You might be fine with this -- you probably want recovery to start your RegionServer (You might be fine with this -- you probably want recovery to start
on the server if a RegionServer has been in GC for a long period of time).</para> on the server if a RegionServer has been in GC for a long period of time).</para>
@ -274,7 +274,7 @@ of all regions.
</para> </para>
<para> <para>
Minimally, a client of HBase needs the hbase, hadoop, log4j, commons-logging, commons-lang, Minimally, a client of HBase needs the hbase, hadoop, log4j, commons-logging, commons-lang,
and zookeeper jars in its <varname>CLASSPATH</varname> connecting to a cluster. and ZooKeeper jars in its <varname>CLASSPATH</varname> connecting to a cluster.
</para> </para>
<para> <para>
An example basic <filename>hbase-site.xml</filename> for client only An example basic <filename>hbase-site.xml</filename> for client only
@ -307,7 +307,7 @@ of all regions.
ensemble for the cluster programmatically do as follows: ensemble for the cluster programmatically do as follows:
<programlisting>Configuration config = HBaseConfiguration.create(); <programlisting>Configuration config = HBaseConfiguration.create();
config.set("hbase.zookeeper.quorum", "localhost"); // Here we are running zookeeper locally</programlisting> config.set("hbase.zookeeper.quorum", "localhost"); // Here we are running zookeeper locally</programlisting>
If multiple ZooKeeper instances make up your zookeeper ensemble, If multiple ZooKeeper instances make up your ZooKeeper ensemble,
they may be specified in a comma-separated list (just as in the <filename>hbase-site.xml</filename> file). they may be specified in a comma-separated list (just as in the <filename>hbase-site.xml</filename> file).
This populated <classname>Configuration</classname> instance can then be passed to an This populated <classname>Configuration</classname> instance can then be passed to an
<link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html">HTable</link>, <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html">HTable</link>,

16
src/docbkx/getting_started.xml
View File

@ -453,7 +453,7 @@ stopping hbase...............</programlisting></para>
in the <xref linkend="quickstart" /> section. In in the <xref linkend="quickstart" /> section. In
standalone mode, HBase does not use HDFS -- it uses the local standalone mode, HBase does not use HDFS -- it uses the local
filesystem instead -- and it runs all HBase daemons and a local filesystem instead -- and it runs all HBase daemons and a local
zookeeper all up in the same JVM. Zookeeper binds to a well known port ZooKeeper all up in the same JVM. Zookeeper binds to a well known port
so clients may talk to HBase.</para> so clients may talk to HBase.</para>
</section> </section>
@ -508,7 +508,7 @@ stopping hbase...............</programlisting></para>
&lt;property&gt; &lt;property&gt;
&lt;name&gt;hbase.rootdir&lt;/name&gt; &lt;name&gt;hbase.rootdir&lt;/name&gt;
&lt;value&gt;hdfs://localhost:9000/hbase&lt;/value&gt; &lt;value&gt;hdfs://localhost:9000/hbase&lt;/value&gt;
&lt;description&gt;The directory shared by region servers. &lt;description&gt;The directory shared by RegionServers.
&lt;/description&gt; &lt;/description&gt;
&lt;/property&gt; &lt;/property&gt;
&lt;property&gt; &lt;property&gt;
@ -539,7 +539,7 @@ stopping hbase...............</programlisting></para>
<para>See <link <para>See <link
xlink:href="http://hbase.apache.org/pseudo-distributed.html">Pseudo-distributed xlink:href="http://hbase.apache.org/pseudo-distributed.html">Pseudo-distributed
mode extras</link> for notes on how to start extra Masters and mode extras</link> for notes on how to start extra Masters and
regionservers when running pseudo-distributed.</para> RegionServers when running pseudo-distributed.</para>
</footnote></para> </footnote></para>
</section> </section>
@ -564,7 +564,7 @@ stopping hbase...............</programlisting></para>
&lt;property&gt; &lt;property&gt;
&lt;name&gt;hbase.rootdir&lt;/name&gt; &lt;name&gt;hbase.rootdir&lt;/name&gt;
&lt;value&gt;hdfs://namenode.example.org:9000/hbase&lt;/value&gt; &lt;value&gt;hdfs://namenode.example.org:9000/hbase&lt;/value&gt;
&lt;description&gt;The directory shared by region servers. &lt;description&gt;The directory shared by RegionServers.
&lt;/description&gt; &lt;/description&gt;
&lt;/property&gt; &lt;/property&gt;
&lt;property&gt; &lt;property&gt;
@ -873,7 +873,7 @@ stopping hbase...............</programlisting> Shutdown can take a moment to
&lt;property&gt; &lt;property&gt;
&lt;name&gt;hbase.zookeeper.quorum&lt;/name&gt; &lt;name&gt;hbase.zookeeper.quorum&lt;/name&gt;
&lt;value&gt;example1,example2,example3&lt;/value&gt; &lt;value&gt;example1,example2,example3&lt;/value&gt;
&lt;description&gt;The directory shared by region servers. &lt;description&gt;The directory shared by RegionServers.
&lt;/description&gt; &lt;/description&gt;
&lt;/property&gt; &lt;/property&gt;
&lt;property&gt; &lt;property&gt;
@ -886,7 +886,7 @@ stopping hbase...............</programlisting> Shutdown can take a moment to
&lt;property&gt; &lt;property&gt;
&lt;name&gt;hbase.rootdir&lt;/name&gt; &lt;name&gt;hbase.rootdir&lt;/name&gt;
&lt;value&gt;hdfs://example0:9000/hbase&lt;/value&gt; &lt;value&gt;hdfs://example0:9000/hbase&lt;/value&gt;
&lt;description&gt;The directory shared by region servers. &lt;description&gt;The directory shared by RegionServers.
&lt;/description&gt; &lt;/description&gt;
&lt;/property&gt; &lt;/property&gt;
&lt;property&gt; &lt;property&gt;
@ -905,8 +905,8 @@ stopping hbase...............</programlisting> Shutdown can take a moment to
<section xml:id="regionservers"> <section xml:id="regionservers">
<title><filename>regionservers</filename></title> <title><filename>regionservers</filename></title>
<para>In this file you list the nodes that will run regionservers. <para>In this file you list the nodes that will run RegionServers.
In our case we run regionservers on all but the head node In our case we run RegionServers on all but the head node
<varname>example1</varname> which is carrying the HBase Master and <varname>example1</varname> which is carrying the HBase Master and
the HDFS namenode</para> the HDFS namenode</para>

20
src/docbkx/performance.xml
View File

@ -16,14 +16,14 @@
here for more pointers.</para> here for more pointers.</para>
<note xml:id="rpc.logging"><title>Enabling RPC-level logging</title> <note xml:id="rpc.logging"><title>Enabling RPC-level logging</title>
<para>Enabling the RPC-level logging on a regionserver can often given <para>Enabling the RPC-level logging on a RegionServer can often given
insight on timings at the server. Once enabled, the amount of log insight on timings at the server. Once enabled, the amount of log
spewed is voluminous. It is not recommended that you leave this spewed is voluminous. It is not recommended that you leave this
logging on for more than short bursts of time. To enable RPC-level logging on for more than short bursts of time. To enable RPC-level
logging, browse to the regionserver UI and click on logging, browse to the RegionServer UI and click on
<emphasis>Log Level</emphasis>. Set the log level to <varname>DEBUG</varname> for the package <emphasis>Log Level</emphasis>. Set the log level to <varname>DEBUG</varname> for the package
<classname>org.apache.hadoop.ipc</classname> (Thats right, for <classname>org.apache.hadoop.ipc</classname> (Thats right, for
hadoop.ipc, NOT, hbase.ipc). Then tail the regionservers log. hadoop.ipc, NOT, hbase.ipc). Then tail the RegionServers log.
Analyze.</para> Analyze.</para>
<para>To disable, set the logging level back to <varname>INFO</varname> level. <para>To disable, set the logging level back to <varname>INFO</varname> level.
</para> </para>
@ -87,13 +87,13 @@
<section xml:id="perf.handlers"> <section xml:id="perf.handlers">
<title><varname>hbase.regionserver.handler.count</varname></title> <title><varname>hbase.regionserver.handler.count</varname></title>
<para>This setting is in essence sets how many requests are <para>This setting is in essence sets how many requests are
concurrently being processed inside the regionserver at any concurrently being processed inside the RegionServer at any
one time. If set too high, then throughput may suffer as one time. If set too high, then throughput may suffer as
the concurrent requests contend; if set too low, requests will the concurrent requests contend; if set too low, requests will
be stuck waiting to get into the machine. You can get a be stuck waiting to get into the machine. You can get a
sense of whether you have too little or too many handlers by sense of whether you have too little or too many handlers by
<xref linkend="rpc.logging" /> <xref linkend="rpc.logging" />
on an individual regionserver then tailing its logs.</para> on an individual RegionServer then tailing its logs.</para>
</section> </section>
</section> </section>
@ -167,7 +167,7 @@ public static byte[][] getHexSplits(String startKey, String endKey, int numRegio
to false on your <link to false on your <link
xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html">HTable</link> xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/HTable.html">HTable</link>
instance. Otherwise, the Puts will be sent one at a time to the instance. Otherwise, the Puts will be sent one at a time to the
regionserver. Puts added via <code> htable.add(Put)</code> and <code> htable.add( &lt;List&gt; Put)</code> RegionServer. Puts added via <code> htable.add(Put)</code> and <code> htable.add( &lt;List&gt; Put)</code>
wind up in the same write buffer. If <code>autoFlush = false</code>, wind up in the same write buffer. If <code>autoFlush = false</code>,
these messages are not sent until the write-buffer is filled. To these messages are not sent until the write-buffer is filled. To
explicitly flush the messages, call <methodname>flushCommits</methodname>. explicitly flush the messages, call <methodname>flushCommits</methodname>.
@ -187,7 +187,7 @@ public static byte[][] getHexSplits(String startKey, String endKey, int numRegio
processed. Setting this value to 500, for example, will transfer 500 processed. Setting this value to 500, for example, will transfer 500
rows at a time to the client to be processed. There is a cost/benefit to rows at a time to the client to be processed. There is a cost/benefit to
have the cache value be large because it costs more in memory for both have the cache value be large because it costs more in memory for both
client and regionserver, so bigger isn't always better.</para> client and RegionServer, so bigger isn't always better.</para>
</section> </section>
<section xml:id="perf.hbase.client.scannerclose"> <section xml:id="perf.hbase.client.scannerclose">
@ -197,7 +197,7 @@ public static byte[][] getHexSplits(String startKey, String endKey, int numRegio
<emphasis>avoiding</emphasis> performance problems. If you forget to <emphasis>avoiding</emphasis> performance problems. If you forget to
close <link close <link
xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/ResultScanner.html">ResultScanners</link> xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/ResultScanner.html">ResultScanners</link>
you can cause problems on the regionservers. Always have ResultScanner you can cause problems on the RegionServers. Always have ResultScanner
processing enclosed in try/catch blocks... <programlisting> processing enclosed in try/catch blocks... <programlisting>
Scan scan = new Scan(); Scan scan = new Scan();
// set attrs... // set attrs...
@ -216,7 +216,7 @@ htable.close();</programlisting></para>
<para><link <para><link
xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Scan.html">Scan</link> xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/client/Scan.html">Scan</link>
instances can be set to use the block cache in the region server via the instances can be set to use the block cache in the RegionServer via the
<methodname>setCacheBlocks</methodname> method. For input Scans to MapReduce jobs, this should be <methodname>setCacheBlocks</methodname> method. For input Scans to MapReduce jobs, this should be
<varname>false</varname>. For frequently accessed rows, it is advisable to use the block <varname>false</varname>. For frequently accessed rows, it is advisable to use the block
cache.</para> cache.</para>
@ -228,7 +228,7 @@ htable.close();</programlisting></para>
<varname>MUST_PASS_ALL</varname> operator to the scanner using <methodname>setFilter</methodname>. The filter list <varname>MUST_PASS_ALL</varname> operator to the scanner using <methodname>setFilter</methodname>. The filter list
should include both a <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/filter/FirstKeyOnlyFilter.html">FirstKeyOnlyFilter</link> should include both a <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/filter/FirstKeyOnlyFilter.html">FirstKeyOnlyFilter</link>
and a <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/filter/KeyOnlyFilter.html">KeyOnlyFilter</link>. and a <link xlink:href="http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/filter/KeyOnlyFilter.html">KeyOnlyFilter</link>.
Using this filter combination will result in a worst case scenario of a region server reading a single value from disk Using this filter combination will result in a worst case scenario of a RegionServer reading a single value from disk
and minimal network traffic to the client for a single row. and minimal network traffic to the client for a single row.
</para> </para>
</section> </section>

8
src/docbkx/troubleshooting.xml
View File

@ -28,7 +28,7 @@
<para> <para>
RegionServer suicides are “normal”, as this is what they do when something goes wrong. RegionServer suicides are “normal”, as this is what they do when something goes wrong.
For example, if ulimit and xcievers (the two most important initial settings, see <xref linkend="ulimit" />) For example, if ulimit and xcievers (the two most important initial settings, see <xref linkend="ulimit" />)
aren’t changed, it will make it impossible at some point for datanodes to create new threads aren’t changed, it will make it impossible at some point for DataNodes to create new threads
that from the HBase point of view is seen as if HDFS was gone. Think about what would happen if your that from the HBase point of view is seen as if HDFS was gone. Think about what would happen if your
MySQL database was suddenly unable to access files on your local file system, well it’s the same with MySQL database was suddenly unable to access files on your local file system, well it’s the same with
HBase and HDFS. Another very common reason to see RegionServers committing seppuku is when they enter HBase and HDFS. Another very common reason to see RegionServers committing seppuku is when they enter
@ -145,7 +145,7 @@ hadoop@sv4borg12:~$ jps
<listitem>Child, its MapReduce task, cannot tell which type exactly</listitem> <listitem>Child, its MapReduce task, cannot tell which type exactly</listitem>
<listitem>Hadoop TaskTracker, manages the local Childs</listitem> <listitem>Hadoop TaskTracker, manages the local Childs</listitem>
<listitem>Hadoop DataNode, serves blocks</listitem> <listitem>Hadoop DataNode, serves blocks</listitem>
<listitem>HQuorumPeer, a zookeeper ensemble member</listitem> <listitem>HQuorumPeer, a ZooKeeper ensemble member</listitem>
<listitem>Jps, well… it’s the current process</listitem> <listitem>Jps, well… it’s the current process</listitem>
<listitem>ThriftServer, it’s a special one will be running only if thrift was started</listitem> <listitem>ThriftServer, it’s a special one will be running only if thrift was started</listitem>
<listitem>jmx, this is a local process that’s part of our monitoring platform ( poorly named maybe). You probably don’t have that.</listitem> <listitem>jmx, this is a local process that’s part of our monitoring platform ( poorly named maybe). You probably don’t have that.</listitem>
@ -275,7 +275,7 @@ hadoop 17789 155 35.2 9067824 8604364 ? S&lt;l Mar04 9855:48 /usr/java/j
</programlisting> </programlisting>
</para> </para>
<para> <para>
And here is a master trying to recover a lease after a region server died: And here is a master trying to recover a lease after a RegionServer died:
<programlisting> <programlisting>
"LeaseChecker" daemon prio=10 tid=0x00000000407ef800 nid=0x76cd waiting on condition [0x00007f6d0eae2000..0x00007f6d0eae2a70] "LeaseChecker" daemon prio=10 tid=0x00000000407ef800 nid=0x76cd waiting on condition [0x00007f6d0eae2000..0x00007f6d0eae2a70]
-- --
@ -370,7 +370,7 @@ java.lang.UnsatisfiedLinkError: no gplcompression in java.library.path
</para> </para>
</section> </section>
<section xml:id="trouble.rs.runtime.oom-nt"> <section xml:id="trouble.rs.runtime.oom-nt">
<title>System instability, and the presence of "java.lang.OutOfMemoryError: unable to create new native thread in exceptions" HDFS datanode logs or that of any system daemon</title> <title>System instability, and the presence of "java.lang.OutOfMemoryError: unable to create new native thread in exceptions" HDFS DataNode logs or that of any system daemon</title>
<para> <para>
See the Getting Started section on <link linkend="ulimit">ulimit and nproc configuration</link>. See the Getting Started section on <link linkend="ulimit">ulimit and nproc configuration</link>.
</para> </para>