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From jruss...@apache.org
Subject [2/7] incubator-impala git commit: New files needed to make PDF build happy.
Date Sat, 29 Oct 2016 00:33:50 GMT
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/1fcc8cee/docs/topics/impala_shell_commands.xml
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diff --git a/docs/topics/impala_shell_commands.xml b/docs/topics/impala_shell_commands.xml
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+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="shell_commands">
+
+  <title>impala-shell Command Reference</title>
+  <titlealts audience="PDF"><navtitle>Command Reference</navtitle></titlealts>
+  <prolog>
+    <metadata>
+      <data name="Category" value="Impala"/>
+      <data name="Category" value="impala-shell"/>
+      <data name="Category" value="SQL"/>
+      <data name="Category" value="Data Analysts"/>
+      <data name="Category" value="Developers"/>
+    </metadata>
+  </prolog>
+
+  <conbody>
+
+    <p>
+      <indexterm audience="Cloudera">impala-shell</indexterm>
+      Use the following commands within <codeph>impala-shell</codeph> to pass requests to the
+      <codeph>impalad</codeph> daemon that the shell is connected to. You can enter a command interactively at the
+      prompt, or pass it as the argument to the <codeph>-q</codeph> option of <codeph>impala-shell</codeph>. Most
+      of these commands are passed to the Impala daemon as SQL statements; refer to the corresponding
+      <xref href="impala_langref_sql.xml#langref_sql">SQL language reference sections</xref> for full syntax
+      details.
+    </p>
+
+    <table>
+      <tgroup cols="2">
+        <colspec colname="1" colwidth="10*"/>
+        <colspec colname="2" colwidth="40*"/>
+        <thead>
+          <row>
+            <entry>
+              Command
+            </entry>
+            <entry>
+              Explanation
+            </entry>
+          </row>
+        </thead>
+        <tbody>
+          <row id="alter_cmd">
+            <entry>
+              <p>
+                <codeph>alter</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Changes the underlying structure or settings of an Impala table, or a table shared between Impala
+                and Hive. See <xref href="impala_alter_table.xml#alter_table"/> and
+                <xref href="impala_alter_view.xml#alter_view"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row rev="1.2.2" id="compute_cmd">
+            <entry>
+              <p>
+                <codeph>compute stats</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Gathers important performance-related information for a table, used by Impala to optimize queries.
+                See <xref href="impala_compute_stats.xml#compute_stats"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row id="connect_cmd">
+            <entry>
+              <p>
+                <codeph>connect</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Connects to the specified instance of <codeph>impalad</codeph>. The default port of 21000 is
+                assumed unless you provide another value. You can connect to any host in your cluster that is
+                running <codeph>impalad</codeph>. If you connect to an instance of <codeph>impalad</codeph> that
+                was started with an alternate port specified by the <codeph>--fe_port</codeph> flag, you must
+                provide that alternate port. See <xref href="impala_connecting.xml#connecting"/> for examples.
+              </p>
+
+              <p conref="../shared/impala_common.xml#common/set_vs_connect"/>
+            </entry>
+          </row>
+          <row id="describe_cmd">
+            <entry>
+              <p>
+                <codeph>describe</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Shows the columns, column data types, and any column comments for a specified table.
+                <codeph>DESCRIBE FORMATTED</codeph> shows additional information such as the HDFS data directory,
+                partitions, and internal properties for the table. See <xref href="impala_describe.xml#describe"/>
+                for details about the basic <codeph>DESCRIBE</codeph> output and the <codeph>DESCRIBE
+                FORMATTED</codeph> variant. You can use <codeph>DESC</codeph> as shorthand for the
+                <codeph>DESCRIBE</codeph> command.
+              </p>
+            </entry>
+          </row>
+          <row id="drop_cmd">
+            <entry>
+              <p>
+                <codeph>drop</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Removes a schema object, and in some cases its associated data files. See
+                <xref href="impala_drop_table.xml#drop_table"/>, <xref href="impala_drop_view.xml#drop_view"/>,
+                <xref href="impala_drop_database.xml#drop_database"/>, and
+                <xref href="impala_drop_function.xml#drop_function"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row id="explain_cmd">
+            <entry>
+              <p>
+                <codeph>explain</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Provides the execution plan for a query. <codeph>EXPLAIN</codeph> represents a query as a series of
+                steps. For example, these steps might be map/reduce stages, metastore operations, or file system
+                operations such as move or rename. See <xref href="impala_explain.xml#explain"/> and
+                <xref href="impala_explain_plan.xml#perf_explain"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row id="help_cmd">
+            <entry>
+              <p>
+                <codeph>help</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Help provides a list of all available commands and options.
+              </p>
+            </entry>
+          </row>
+          <row id="history_cmd">
+            <entry>
+              <p>
+                <codeph>history</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Maintains an enumerated cross-session command history. This history is stored in the
+                <filepath>~/.impalahistory</filepath> file.
+              </p>
+            </entry>
+          </row>
+          <row id="insert_cmd">
+            <entry>
+              <p>
+                <codeph>insert</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Writes the results of a query to a specified table. This either overwrites table data or appends
+                data to the existing table content. See <xref href="impala_insert.xml#insert"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row id="invalidate_metadata_cmd">
+            <entry>
+              <p>
+                <codeph>invalidate metadata</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Updates <cmdname>impalad</cmdname> metadata for table existence and structure. Use this command
+                after creating, dropping, or altering databases, tables, or partitions in Hive. See
+                <xref href="impala_invalidate_metadata.xml#invalidate_metadata"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row id="profile_cmd">
+            <entry>
+              <p>
+                <codeph>profile</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Displays low-level information about the most recent query. Used for performance diagnosis and
+                tuning. <ph rev="1.4.0"> The report starts with the same information as produced by the
+                <codeph>EXPLAIN</codeph> statement and the <codeph>SUMMARY</codeph> command.</ph> See
+                <xref href="impala_explain_plan.xml#perf_profile"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row id="quit_cmd">
+            <entry>
+              <p>
+                <codeph>quit</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Exits the shell. Remember to include the final semicolon so that the shell recognizes the end of
+                the command.
+              </p>
+            </entry>
+          </row>
+          <row id="refresh_cmd">
+            <entry>
+              <p>
+                <codeph>refresh</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Refreshes <cmdname>impalad</cmdname> metadata for the locations of HDFS blocks corresponding to
+                Impala data files. Use this command after loading new data files into an Impala table through Hive
+                or through HDFS commands. See <xref href="impala_refresh.xml#refresh"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row id="select_cmd">
+            <entry>
+              <p>
+                <codeph>select</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Specifies the data set on which to complete some action. All information returned from
+                <codeph>select</codeph> can be sent to some output such as the console or a file or can be used to
+                complete some other element of query. See <xref href="impala_select.xml#select"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row id="set_cmd">
+            <entry>
+              <p>
+                <codeph>set</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Manages query options for an <cmdname>impala-shell</cmdname> session. The available options are the
+                ones listed in <xref href="impala_query_options.xml#query_options"/>. These options are used for
+                query tuning and troubleshooting. Issue <codeph>SET</codeph> with no arguments to see the current
+                query options, either based on the <cmdname>impalad</cmdname> defaults, as specified by you at
+                <cmdname>impalad</cmdname> startup, or based on earlier <codeph>SET</codeph> statements in the same
+                session. To modify option values, issue commands with the syntax <codeph>set
+                <varname>option</varname>=<varname>value</varname></codeph>. To restore an option to its default,
+                use the <codeph>unset</codeph> command. Some options take Boolean values of <codeph>true</codeph>
+                and <codeph>false</codeph>. Others take numeric arguments, or quoted string values.
+              </p>
+
+              <p conref="../shared/impala_common.xml#common/set_vs_connect"/>
+
+              <p rev="2.0.0">
+                In Impala 2.0 and later, <codeph>SET</codeph> is available as a SQL statement for any kind of
+                application, not only through <cmdname>impala-shell</cmdname>. See
+                <xref href="impala_set.xml#set"/> for details.
+              </p>
+
+              <p rev="2.5.0 IMPALA-2180">
+                In Impala 2.5 and later, you can use <codeph>SET</codeph> to define your own substitution variables
+                within an <cmdname>impala-shell</cmdname> session.
+                Within a SQL statement, you substitute the value by using the notation <codeph>${var:<varname>variable_name</varname>}</codeph>.
+              </p>
+            </entry>
+          </row>
+          <row id="shell_cmd">
+            <entry>
+              <p>
+                <codeph>shell</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Executes the specified command in the operating system shell without exiting
+                <codeph>impala-shell</codeph>. You can use the <codeph>!</codeph> character as shorthand for the
+                <codeph>shell</codeph> command.
+              </p>
+
+              <note>
+                Quote any instances of the <codeph>--</codeph> or <codeph>/*</codeph> tokens to avoid them being
+                interpreted as the start of a comment. To embed comments within <codeph>source</codeph> or
+                <codeph>!</codeph> commands, use the shell comment character <codeph>#</codeph> before the comment
+                portion of the line.
+              </note>
+            </entry>
+          </row>
+          <row id="show_cmd">
+            <entry>
+              <p>
+                <codeph>show</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Displays metastore data for schema objects created and accessed through Impala, Hive, or both.
+                <codeph>show</codeph> can be used to gather information about objects such as databases, tables, and functions.
+                See <xref href="impala_show.xml#show"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row id="source_cmd" rev="IMPALA-3397 CDH-40097">
+            <entry>
+              <p>
+                <codeph>source</codeph> or <codeph>src</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Executes one or more statements residing in a specified file from the local filesystem.
+                Allows you to perform the same kinds of batch operations as with the <codeph>-f</codeph> option,
+                but interactively within the interpreter. The file can contain SQL statements and other
+                <cmdname>impala-shell</cmdname> commands, including additional <codeph>SOURCE</codeph> commands
+                to perform a flexible sequence of actions. Each command or statement, except the last one in the file,
+                must end with a semicolon.
+                See <xref href="impala_shell_running_commands.xml#shell_running_commands"/> for examples.
+              </p>
+            </entry>
+          </row>
+          <row rev="1.4.0" id="summary_cmd">
+            <entry>
+              <p>
+                <codeph>summary</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Summarizes the work performed in various stages of a query. It provides a higher-level view of the
+                information displayed by the <codeph>EXPLAIN</codeph> command. Added in Impala 1.4.0. See
+                <xref href="impala_explain_plan.xml#perf_summary"/> for details about the report format
+                and how to interpret it.
+              </p>
+              <p rev="2.3.0">
+                In CDH 5.5 / Impala 2.3 and higher, you can see a continuously updated report of
+                the summary information while a query is in progress.
+                See <xref href="impala_live_summary.xml#live_summary"/> for details.
+              </p>
+            </entry>
+          </row>
+          <row id="unset_cmd">
+            <entry>
+              <p>
+                <codeph>unset</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Removes any user-specified value for a query option and returns the option to its default value.
+                See <xref href="impala_query_options.xml#query_options"/> for the available query options.
+              </p>
+              <p rev="2.5.0 IMPALA-2180">
+                In CDH 5.7 / Impala 2.5 and higher, it can also remove user-specified substitution variables
+                using the notation <codeph>UNSET VAR:<varname>variable_name</varname></codeph>.
+              </p>
+            </entry>
+          </row>
+          <row id="use_cmd">
+            <entry>
+              <p>
+                <codeph>use</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Indicates the database against which to execute subsequent commands. Lets you avoid using fully
+                qualified names when referring to tables in databases other than <codeph>default</codeph>. See
+                <xref href="impala_use.xml#use"/> for details. Not effective with the <codeph>-q</codeph> option,
+                because that option only allows a single statement in the argument.
+              </p>
+            </entry>
+          </row>
+          <row id="version_cmd">
+            <entry>
+              <p>
+                <codeph>version</codeph>
+              </p>
+            </entry>
+            <entry>
+              <p>
+                Returns Impala version information.
+              </p>
+            </entry>
+          </row>
+        </tbody>
+      </tgroup>
+    </table>
+  </conbody>
+</concept>

http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/1fcc8cee/docs/topics/impala_shell_running_commands.xml
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diff --git a/docs/topics/impala_shell_running_commands.xml b/docs/topics/impala_shell_running_commands.xml
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+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="shell_running_commands">
+
+  <title>Running Commands and SQL Statements in impala-shell</title>
+  <titlealts audience="PDF"><navtitle>Running Commands and SQL Statements</navtitle></titlealts>
+  <prolog>
+    <metadata>
+      <data name="Category" value="Impala"/>
+      <data name="Category" value="impala-shell"/>
+      <data name="Category" value="SQL"/>
+      <data name="Category" value="Data Analysts"/>
+      <data name="Category" value="Developers"/>
+    </metadata>
+  </prolog>
+
+  <conbody>
+
+    <p>
+      For information on available commands, see
+      <xref href="impala_shell_commands.xml#shell_commands"/>. You can see the full set of available
+      commands by pressing TAB twice, for example:
+    </p>
+
+<codeblock>[impalad-host:21000] &gt;
+connect   describe  explain   help      history   insert    quit      refresh   select    set       shell     show      use       version
+[impalad-host:21000] &gt;</codeblock>
+
+    <note>
+      Commands must be terminated by a semi-colon. A command can span multiple lines.
+    </note>
+
+    <p>
+      For example:
+    </p>
+
+<codeblock>[localhost:21000] &gt; select *
+                  &gt; from t1
+                  &gt; limit 5;
++---------+-----------+
+| s1      | s2        |
++---------+-----------+
+| hello   | world     |
+| goodbye | cleveland |
++---------+-----------+
+</codeblock>
+
+    <p>
+      A comment is considered part of the statement it precedes, so when you enter a <codeph>--</codeph> or
+      <codeph>/* */</codeph> comment, you get a continuation prompt until you finish entering a statement ending
+      with a semicolon:
+    </p>
+
+<codeblock>[localhost:21000] &gt; -- This is a test comment
+                  &gt; show tables like 't*';
++--------+
+| name   |
++--------+
+| t1     |
+| t2     |
+| tab1   |
+| tab2   |
+| tab3   |
+| text_t |
++--------+
+</codeblock>
+
+    <p>
+      Use the up-arrow and down-arrow keys to cycle through and edit previous commands.
+      <cmdname>impala-shell</cmdname> uses the <codeph>readline</codeph> library and so supports a standard set of
+      keyboard shortcuts for editing and cursor movement, such as <codeph>Ctrl-A</codeph> for beginning of line and
+      <codeph>Ctrl-E</codeph> for end of line.
+    </p>
+
+    <p rev="2.5.0 IMPALA-2179 IMPALA-2180">
+      In CDH 5.7 / Impala 2.5 and higher, you can define substitution variables to be used within SQL statements
+      processed by <cmdname>impala-shell</cmdname>. On the command line, you specify the option
+      <codeph>--var=<varname>variable_name</varname>=<varname>value</varname></codeph>.
+      Within an interactive session or a script file processed by the <codeph>-f</codeph> option, you specify
+      a <codeph>SET</codeph> command using the notation <codeph>SET VAR:<varname>variable_name</varname>=<varname>value</varname></codeph>.
+      Within a SQL statement, you substitute the value by using the notation <codeph>${var:<varname>variable_name</varname>}</codeph>.
+    </p>
+
+    <note>
+      Because this feature is part of <cmdname>impala-shell</cmdname> rather than the <cmdname>impalad</cmdname>
+      backend, make sure the client system you are connecting from has the most recent <cmdname>impala-shell</cmdname>.
+      You can use this feature with a new <cmdname>impala-shell</cmdname> connecting to an older <cmdname>impalad</cmdname>,
+      but not the reverse.
+    </note>
+
+    <p rev="2.5.0 IMPALA-2179 IMPALA-2180">
+      For example, here are some <cmdname>impala-shell</cmdname> commands that define substitution variables and then
+      use them in SQL statements executed through the <codeph>-q</codeph> and <codeph>-f</codeph> options.
+      Notice how the <codeph>-q</codeph> argument strings are single-quoted to prevent shell expansion of the
+      <codeph>${var:value}</codeph> notation, and any string literals within the queries are enclosed by double quotation marks.
+    </p>
+
+<codeblock rev="2.5.0 IMPALA-2179 IMPALA-2180">
+$ impala-shell --var=tname=table1 --var=colname=x --var=coltype=string -q 'create table ${var:tname} (${var:colname} ${var:coltype}) stored as parquet'
+Starting Impala Shell without Kerberos authentication
+Connected to <varname>hostname</varname>
+Server version: <varname>impalad_version</varname>
+Query: create table table1 (x string) stored as parquet
+
+$ NEW_STRING="hello world"
+$ impala-shell --var=tname=table1 --var=insert_val="$NEW_STRING" -q 'insert into ${var:tname} values ("${var:insert_val}")'
+Starting Impala Shell without Kerberos authentication
+Connected to <varname>hostname</varname>
+Server version: <varname>impalad_version</varname>
+Query: insert into table1 values ("hello world")
+Inserted 1 row(s) in 1.40s
+
+$ for VAL in foo bar bletch
+do
+  impala-shell --var=tname=table1 --var=insert_val="$VAL" -q 'insert into ${var:tname} values ("${var:insert_val}")'
+done
+...
+Query: insert into table1 values ("foo")
+Inserted 1 row(s) in 0.22s
+Query: insert into table1 values ("bar")
+Inserted 1 row(s) in 0.11s
+Query: insert into table1 values ("bletch")
+Inserted 1 row(s) in 0.21s
+
+$ echo "Search for what substring?" ; read answer
+Search for what substring?
+b
+$ impala-shell --var=tname=table1 -q 'select x from ${var:tname} where x like "%${var:answer}%"'
+Starting Impala Shell without Kerberos authentication
+Connected to <varname>hostname</varname>
+Server version: <varname>impalad_version</varname>
+Query: select x from table1 where x like "%b%"
++--------+
+| x      |
++--------+
+| bletch |
+| bar    |
++--------+
+Fetched 2 row(s) in 0.83s
+</codeblock>
+
+    <p rev="2.5.0 IMPALA-2179 IMPALA-2180">
+      Here is a substitution variable passed in by the <codeph>--var</codeph> option,
+      and then referenced by statements issued interactively. Then the variable is
+      cleared with the <codeph>UNSET</codeph> command, and defined again with the
+      <codeph>SET</codeph> command.
+    </p>
+
+<codeblock rev="2.5.0 IMPALA-2179 IMPALA-2180">
+$ impala-shell --quiet --var=tname=table1
+Starting Impala Shell without Kerberos authentication
+***********************************************************************************
+<varname>banner_message</varname>
+***********************************************************************************
+[<varname>hostname</varname>:21000] > select count(*) from ${var:tname};
++----------+
+| count(*) |
++----------+
+| 4        |
++----------+
+[<varname>hostname</varname>:21000] > unset var:tname;
+Unsetting variable TNAME
+[<varname>hostname</varname>:21000] > select count(*) from ${var:tname};
+Error: Unknown variable TNAME
+[<varname>hostname</varname>:21000] > set var:tname=table1;
+[<varname>hostname</varname>:21000] > select count(*) from ${var:tname};
++----------+
+| count(*) |
++----------+
+| 4        |
++----------+
+</codeblock>
+
+    <p rev="IMPALA-3397 CDH-40097">
+      The following example shows how the <codeph>SOURCE</codeph> command can execute
+      a series of statements from a file:
+    </p>
+
+<codeblock rev="IMPALA-3397 CDH-40097">
+$ cat commands.sql
+show databases;
+show tables in default;
+show functions in _impala_builtins like '*minute*';
+
+$ impala-shell -i localhost
+...
+[localhost:21000] > source commands.sql;
+Query: show databases
++------------------+----------------------------------------------+
+| name             | comment                                      |
++------------------+----------------------------------------------+
+| _impala_builtins | System database for Impala builtin functions |
+| default          | Default Hive database                        |
++------------------+----------------------------------------------+
+Fetched 2 row(s) in 0.06s
+Query: show tables in default
++-----------+
+| name      |
++-----------+
+| customers |
+| sample_07 |
+| sample_08 |
+| web_logs  |
++-----------+
+Fetched 4 row(s) in 0.02s
+Query: show functions in _impala_builtins like '*minute*'
++-------------+--------------------------------+-------------+---------------+
+| return type | signature                      | binary type | is persistent |
++-------------+--------------------------------+-------------+---------------+
+| INT         | minute(TIMESTAMP)              | BUILTIN     | true          |
+| TIMESTAMP   | minutes_add(TIMESTAMP, BIGINT) | BUILTIN     | true          |
+| TIMESTAMP   | minutes_add(TIMESTAMP, INT)    | BUILTIN     | true          |
+| TIMESTAMP   | minutes_sub(TIMESTAMP, BIGINT) | BUILTIN     | true          |
+| TIMESTAMP   | minutes_sub(TIMESTAMP, INT)    | BUILTIN     | true          |
++-------------+--------------------------------+-------------+---------------+
+Fetched 5 row(s) in 0.03s
+</codeblock>
+
+    <p rev="IMPALA-3397 CDH-40097">
+      The following example shows how a file that is run by the <codeph>SOURCE</codeph> command,
+      or through the <codeph>-q</codeph> or <codeph>-f</codeph> options of <cmdname>impala-shell</cmdname>,
+      can contain additional <codeph>SOURCE</codeph> commands.
+      The first file, <filepath>nested1.sql</filepath>, runs an <cmdname>impala-shell</cmdname> command
+      and then also runs the commands from <filepath>nested2.sql</filepath>.
+      This ability for scripts to call each other is often useful for code that sets up schemas for applications
+      or test environments.
+    </p>
+
+<codeblock rev="IMPALA-3397 CDH-40097">
+$ cat nested1.sql
+show functions in _impala_builtins like '*minute*';
+source nested2.sql
+$ cat nested2.sql
+show functions in _impala_builtins like '*hour*'
+
+$ impala-shell -i localhost -f nested1.sql
+Starting Impala Shell without Kerberos authentication
+Connected to localhost:21000
+...
+Query: show functions in _impala_builtins like '*minute*'
++-------------+--------------------------------+-------------+---------------+
+| return type | signature                      | binary type | is persistent |
++-------------+--------------------------------+-------------+---------------+
+| INT         | minute(TIMESTAMP)              | BUILTIN     | true          |
+| TIMESTAMP   | minutes_add(TIMESTAMP, BIGINT) | BUILTIN     | true          |
+| TIMESTAMP   | minutes_add(TIMESTAMP, INT)    | BUILTIN     | true          |
+| TIMESTAMP   | minutes_sub(TIMESTAMP, BIGINT) | BUILTIN     | true          |
+| TIMESTAMP   | minutes_sub(TIMESTAMP, INT)    | BUILTIN     | true          |
++-------------+--------------------------------+-------------+---------------+
+Fetched 5 row(s) in 0.01s
+Query: show functions in _impala_builtins like '*hour*'
++-------------+------------------------------+-------------+---------------+
+| return type | signature                    | binary type | is persistent |
++-------------+------------------------------+-------------+---------------+
+| INT         | hour(TIMESTAMP)              | BUILTIN     | true          |
+| TIMESTAMP   | hours_add(TIMESTAMP, BIGINT) | BUILTIN     | true          |
+| TIMESTAMP   | hours_add(TIMESTAMP, INT)    | BUILTIN     | true          |
+| TIMESTAMP   | hours_sub(TIMESTAMP, BIGINT) | BUILTIN     | true          |
+| TIMESTAMP   | hours_sub(TIMESTAMP, INT)    | BUILTIN     | true          |
++-------------+------------------------------+-------------+---------------+
+Fetched 5 row(s) in 0.01s
+</codeblock>
+
+  </conbody>
+</concept>

http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/1fcc8cee/docs/topics/impala_ssl.xml
----------------------------------------------------------------------
diff --git a/docs/topics/impala_ssl.xml b/docs/topics/impala_ssl.xml
new file mode 100644
index 0000000..56e86a0
--- /dev/null
+++ b/docs/topics/impala_ssl.xml
@@ -0,0 +1,256 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="ssl">
+
+  <title id="tls">Configuring TLS/SSL for Impala</title>
+
+  <prolog>
+    <metadata>
+      <data name="Category" value="Impala"/>
+      <data name="Category" value="Security"/>
+      <data name="Category" value="SSL"/>
+      <data name="Category" value="Encryption"/>
+      <data name="Category" value="Configuring"/>
+      <data name="Category" value="Administrators"/>
+    </metadata>
+  </prolog>
+
+  <conbody>
+
+    <p>
+      <indexterm audience="Cloudera">SSL</indexterm>
+      Impala supports TLS/SSL network encryption, between Impala and client programs, and between the Impala-related daemons running on
+      different nodes in the cluster. This feature is important when you also use other features such as Kerberos authentication or Sentry
+      authorization, where credentials are being transmitted back and forth.
+      <note conref="../shared/CDHVariables.xml#xd_583c10bfdbd326ba-3ca24a24-13d80143249--7f9a/CMCDH_EitherOK"
+      />
+    </p>
+
+  </conbody>
+
+  <concept id="concept_gnk_2tt_qp">
+
+    <title>Using Cloudera Manager</title>
+
+    <prolog>
+      <metadata>
+        <data name="Category" value="Cloudera Manager"/>
+      </metadata>
+    </prolog>
+
+    <conbody>
+
+      <p>
+        To configure Impala to listen for Beeswax and HiveServer2 requests on TLS/SSL-secured ports:
+        <ol id="ol_rnf_ftt_qp">
+          <li>
+            Open the Cloudera Manager Admin Console and go to the <uicontrol>Impala</uicontrol> service.
+          </li>
+
+          <li
+            conref="../shared/cm_common_elements.xml#cm/config_edit"/>
+
+          <li>
+            Select <menucascade><uicontrol>Scope</uicontrol><uicontrol>Impala (Service-Wide)</uicontrol></menucascade>.
+          </li>
+
+          <li>
+            Select <menucascade><uicontrol>Category</uicontrol><uicontrol>Security</uicontrol></menucascade>.
+          </li>
+
+          <li>
+            Edit the following properties:
+            <table frame="all"
+              id="table_drf_ftt_qp">
+              <title>Impala SSL Properties</title>
+              <tgroup cols="2">
+                <colspec colname="c1" colnum="1" colwidth="1*"/>
+                <colspec colname="c2" colnum="2" colwidth="2.5*"/>
+                <thead>
+                  <row>
+                    <entry>
+                      Property
+                    </entry>
+                    <entry>
+                      Description
+                    </entry>
+                  </row>
+                </thead>
+                <tbody>
+                  <row>
+                    <entry>
+                      <b>Enable TLS/SSL for Impala Client Services</b>
+                    </entry>
+                    <entry>
+                      Encrypt communication between clients (like ODBC, JDBC, and the Impala shell) and the Impala daemon using Transport
+                      Layer Security (TLS) (formerly known as Secure Socket Layer (SSL)).
+                    </entry>
+                  </row>
+                  <row>
+                    <entry>
+                      <b>SSL/TLS Certificate for Clients</b>
+                    </entry>
+                    <entry>
+                      Local path to the X509 certificate that identifies the Impala daemon to clients during TLS/SSL connections. This
+                      file must be in PEM format.
+                    </entry>
+                  </row>
+                  <row>
+                    <entry>
+                      <b>SSL/TLS Private Key for Clients</b>
+                    </entry>
+                    <entry>
+                      Local path to the private key that matches the certificate specified in the Certificate for Clients. This file must be
+                      in PEM format.
+                    </entry>
+                  </row>
+                  <row>
+                    <entry>
+                      <b>SSL/TLS Private Key Password for Clients</b>
+                    </entry>
+                    <entry>
+                      A shell command for Impala to run on startup to retrieve the password for a password-protected private key file.
+                      The output of the command is truncated to a maximum of 1024 bytes, and any trailing whitespace (such as spaces
+                      or newline characters) is trimmed. If the command exits with an error, Impala does not start. If the password
+                      is incorrect, clients cannot connect to the server regardless of whether the public key is correct.
+                    </entry>
+                  </row>
+                  <row>
+                    <entry>
+                      <b>SSL/TLS CA Certificate</b>
+                    </entry>
+                    <entry>
+                      Must be specified for TLS/SSL encryption to be enabled for communication
+                      between internal Impala components.
+                    </entry>
+                  </row>
+                  <row>
+                    <entry>
+                      <b>SSL/TLS Certificate for <varname>Impala component</varname> Webserver</b>
+                    </entry>
+                    <entry>
+                      There are three of these configuration settings, one each for <q>Impala Daemon</q>,
+                      <q>Catalog Server</q>, and <q>Statestore</q>.
+                      Each of these Impala components has its own internal web server that powers the
+                      associated web UI with diagnostic information.
+                      The configuration setting represents the local path to the X509 certificate that
+                      identifies the web server to clients during TLS/SSL connections. This
+                      file must be in PEM format.
+                    </entry>
+                  </row>
+                </tbody>
+              </tgroup>
+            </table>
+          </li>
+
+          <li conref="../shared/cm_common_elements.xml#cm/save_changes_short"/>
+
+          <li>
+            Restart the Impala service.
+          </li>
+        </ol>
+      </p>
+
+      <p>
+        For information on configuring TLS/SSL communication with the <codeph>impala-shell</codeph> interpreter, see
+        <xref href="#concept_q1p_j2d_rp/secref"/>.
+      </p>
+
+    </conbody>
+
+  </concept>
+
+  <concept id="concept_q1p_j2d_rp">
+
+    <title>Using the Command Line</title>
+
+    <conbody>
+
+<!--
+Info from Henry, from https://docs.google.com/a/cloudera.com/document/d/1u00CJ8WRzXR-1AK_WnQlR6LMtY-7Rc3eHaKNgw3IZvA/edit
+-->
+
+      <p>
+        To enable SSL for when client applications connect to Impala, add both of the following flags to the <cmdname>impalad</cmdname> startup options:
+      </p>
+
+      <ul id="ul_i2p_m2d_rp">
+        <li>
+          <codeph>--ssl_server_certificate</codeph>: the full path to the server certificate, on the local filesystem.
+        </li>
+
+        <li>
+          <codeph>--ssl_private_key</codeph>: the full path to the server private key, on the local filesystem.
+        </li>
+      </ul>
+
+      <p rev="2.3.0">
+        In CDH 5.5 / Impala 2.3 and higher, Impala can also use SSL for its own internal communication between the
+        <cmdname>impalad</cmdname>, <codeph>statestored</codeph>, and <codeph>catalogd</codeph> daemons.
+        To enable this additional SSL encryption, set the <codeph>--ssl_server_certificate</codeph>
+        and <codeph>--ssl_private_key</codeph> flags in the startup options for
+        <cmdname>impalad</cmdname>, <cmdname>catalogd</cmdname>, and <cmdname>statestored</cmdname>,
+        and also add the <codeph>--ssl_client_ca_certificate</codeph> flag for all three of those daemons.
+      </p>
+
+      <note conref="../shared/impala_common.xml#common/impala_kerberos_ssl_caveat"/>
+
+      <p>
+        If either of these flags are set, both must be set. In that case, Impala starts listening for Beeswax and HiveServer2 requests on
+        SSL-secured ports only. (The port numbers stay the same; see <xref href="impala_ports.xml#ports"/> for details.)
+      </p>
+
+      <p>
+        Since Impala uses passphrase-less certificates in PEM format, you can reuse a host's existing Java keystore by converting it to the
+        PEM format. For instructions, see
+        <xref audience="integrated" href="cm_sg_openssl_jks.xml#concept_ek3_sdl_rp"/><xref audience="standalone" href="http://www.cloudera.com/documentation/enterprise/latest/topics/cm_sg_openssl_jks.html" scope="external" format="html"/>.
+      </p>
+
+      <section id="secref">
+
+        <title>Configuring TLS/SSL Communication for the Impala Shell</title>
+
+        <p>
+          Typically, a client program has corresponding configuration properties in Cloudera Manager to verify that it is connecting to the
+          right server. For example, with SSL enabled for Impala, you use the following options when starting the
+          <cmdname>impala-shell</cmdname> interpreter:
+        </p>
+
+        <ul id="ul_kgp_m2d_rp">
+          <li>
+            <codeph>--ssl</codeph>: enables TLS/SSL for <cmdname>impala-shell</cmdname>.
+          </li>
+
+          <li>
+            <codeph>--ca_cert</codeph>: the local pathname pointing to the third-party CA certificate, or to a copy of the server
+            certificate for self-signed server certificates.
+          </li>
+        </ul>
+
+        <p>
+          If <codeph>--ca_cert</codeph> is not set, <cmdname>impala-shell</cmdname> enables TLS/SSL, but does not validate the server
+          certificate. This is useful for connecting to a known-good Impala that is only running over TLS/SSL, when a copy of the
+          certificate is not available (such as when debugging customer installations).
+        </p>
+
+      </section>
+
+    </conbody>
+
+  </concept>
+
+  <concept id="ssl_jdbc_odbc">
+    <title>Using TLS/SSL with Business Intelligence Tools</title>
+    <conbody>
+      <p>
+        You can use Kerberos authentication, TLS/SSL encryption, or both to secure
+        connections from JDBC and ODBC applications to Impala.
+        See <xref href="impala_jdbc.xml#impala_jdbc"/> and <xref href="impala_odbc.xml#impala_odbc"/>
+        for details.
+      </p>
+
+      <p conref="../shared/impala_common.xml#common/hive_jdbc_ssl_kerberos_caveat"/>
+    </conbody>
+  </concept>
+
+</concept>

http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/1fcc8cee/docs/topics/impala_troubleshooting.xml
----------------------------------------------------------------------
diff --git a/docs/topics/impala_troubleshooting.xml b/docs/topics/impala_troubleshooting.xml
new file mode 100644
index 0000000..f7ebe4e
--- /dev/null
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+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="troubleshooting">
+
+  <title>Troubleshooting Impala</title>
+  <prolog>
+    <metadata>
+      <data name="Category" value="Impala"/>
+      <data name="Category" value="Troubleshooting"/>
+      <data name="Category" value="Administrators"/>
+      <data name="Category" value="Developers"/>
+      <data name="Category" value="Data Analysts"/>
+    </metadata>
+  </prolog>
+
+  <conbody>
+
+    <p>
+      <indexterm audience="Cloudera">troubleshooting</indexterm>
+      Troubleshooting for Impala requires being able to diagnose and debug problems
+      with performance, network connectivity, out-of-memory conditions, disk space usage,
+      and crash or hang conditions in any of the Impala-related daemons.
+    </p>
+
+    <p outputclass="toc inpage" audience="PDF">
+      The following sections describe the general troubleshooting procedures to diagnose
+      different kinds of problems:
+    </p>
+
+  </conbody>
+
+  <concept id="trouble_sql">
+
+    <title>Troubleshooting Impala SQL Syntax Issues</title>
+
+    <conbody>
+
+      <p>
+        In general, if queries issued against Impala fail, you can try running these same queries against Hive.
+      </p>
+
+      <ul>
+        <li>
+          If a query fails against both Impala and Hive, it is likely that there is a problem with your query or
+          other elements of your CDH environment:
+          <ul>
+            <li>
+              Review the <xref href="impala_langref.xml#langref">Language Reference</xref> to ensure your query is
+              valid.
+            </li>
+
+            <li>
+              Check <xref href="impala_reserved_words.xml#reserved_words"/> to see if any database, table,
+              column, or other object names in your query conflict with Impala reserved words.
+              Quote those names with backticks (<codeph>``</codeph>) if so.
+            </li>
+
+            <li>
+              Check <xref href="impala_functions.xml#builtins"/> to confirm whether Impala supports all the
+              built-in functions being used by your query, and whether argument and return types are the
+              same as you expect.
+            </li>
+
+            <li>
+              Review the <xref href="impala_logging.xml#logs_debug">contents of the Impala logs</xref> for any information that may be useful in identifying the
+              source of the problem.
+            </li>
+          </ul>
+        </li>
+
+        <li>
+          If a query fails against Impala but not Hive, it is likely that there is a problem with your Impala
+          installation.
+        </li>
+      </ul>
+    </conbody>
+  </concept>
+
+  <concept id="trouble_io" rev="CDH-19201">
+    <title>Troubleshooting I/O Capacity Problems</title>
+    <conbody>
+      <p>
+        Impala queries are typically I/O-intensive. If there is an I/O problem with storage devices,
+        or with HDFS itself, Impala queries could show slow response times with no obvious cause
+        on the Impala side. Slow I/O on even a single DataNode could result in an overall slowdown, because
+        queries involving clauses such as <codeph>ORDER BY</codeph>, <codeph>GROUP BY</codeph>, or <codeph>JOIN</codeph>
+        do not start returning results until all DataNodes have finished their work.
+      </p>
+      <p>
+        To test whether the Linux I/O system itself is performing as expected, run Linux commands like
+        the following on each DataNode:
+      </p>
+<codeblock>
+$ sudo sysctl -w vm.drop_caches=3 vm.drop_caches=0
+vm.drop_caches = 3
+vm.drop_caches = 0
+$ sudo dd if=/dev/sda bs=1M of=/dev/null count=1k 
+1024+0 records in
+1024+0 records out
+1073741824 bytes (1.1 GB) copied, 5.60373 s, 192 MB/s
+$ sudo dd if=/dev/sdb bs=1M of=/dev/null count=1k
+1024+0 records in
+1024+0 records out
+1073741824 bytes (1.1 GB) copied, 5.51145 s, 195 MB/s
+$ sudo dd if=/dev/sdc bs=1M of=/dev/null count=1k
+1024+0 records in
+1024+0 records out
+1073741824 bytes (1.1 GB) copied, 5.58096 s, 192 MB/s
+$ sudo dd if=/dev/sdd bs=1M of=/dev/null count=1k
+1024+0 records in
+1024+0 records out
+1073741824 bytes (1.1 GB) copied, 5.43924 s, 197 MB/s
+</codeblock>
+      <p>
+        On modern hardware, a throughput rate of less than 100 MB/s typically indicates
+        a performance issue with the storage device. Correct the hardware problem before
+        continuing with Impala tuning or benchmarking.
+      </p>
+    </conbody>
+  </concept>
+
+
+  <concept id="trouble_cookbook">
+
+    <title>Impala Troubleshooting Quick Reference</title>
+
+    <conbody>
+
+      <p>
+        The following table lists common problems and potential solutions.
+      </p>
+
+      <table>
+        <tgroup cols="3">
+          <colspec colname="1" colwidth="10*"/>
+          <colspec colname="2" colwidth="30*"/>
+          <colspec colname="3" colwidth="30*"/>
+          <thead>
+            <row>
+              <entry>
+                Symptom
+              </entry>
+              <entry>
+                Explanation
+              </entry>
+              <entry>
+                Recommendation
+              </entry>
+            </row>
+          </thead>
+          <tbody>
+            <row>
+              <entry>
+                Impala takes a long time to start.
+              </entry>
+              <entry>
+                Impala instances with large numbers of tables, partitions, or data files take longer to start
+                because the metadata for these objects is broadcast to all <cmdname>impalad</cmdname> nodes and
+                cached.
+              </entry>
+              <entry>
+                Adjust timeout and synchronicity settings.
+              </entry>
+            </row>
+            <row>
+              <entry>
+                <p>
+                  Joins fail to complete.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  There may be insufficient memory. During a join, data from the second, third, and so on sets to
+                  be joined is loaded into memory. If Impala chooses an inefficient join order or join mechanism,
+                  the query could exceed the total memory available.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  Start by gathering statistics with the <codeph>COMPUTE STATS</codeph> statement for each table
+                  involved in the join. Consider specifying the <codeph>[SHUFFLE]</codeph> hint so that data from
+                  the joined tables is split up between nodes rather than broadcast to each node. If tuning at the
+                  SQL level is not sufficient, add more memory to your system or join smaller data sets.
+                </p>
+              </entry>
+            </row>
+            <row>
+              <entry>
+                <p>
+                  Queries return incorrect results.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  Impala metadata may be outdated after changes are performed in Hive.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  Where possible, use the appropriate Impala statement (<codeph>INSERT</codeph>, <codeph>LOAD
+                  DATA</codeph>, <codeph>CREATE TABLE</codeph>, <codeph>ALTER TABLE</codeph>, <codeph>COMPUTE
+                  STATS</codeph>, and so on) rather than switching back and forth between Impala and Hive. Impala
+                  automatically broadcasts the results of DDL and DML operations to all Impala nodes in the
+                  cluster, but does not automatically recognize when such changes are made through Hive. After
+                  inserting data, adding a partition, or other operation in Hive, refresh the metadata for the
+                  table as described in <xref href="impala_refresh.xml#refresh"/>.
+                </p>
+              </entry>
+            </row>
+            <row>
+              <entry>
+                <p>
+                  Queries are slow to return results.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  Some <codeph>impalad</codeph> instances may not have started. Using a browser, connect to the
+                  host running the Impala state store. Connect using an address of the form
+                  <codeph>http://<varname>hostname</varname>:<varname>port</varname>/metrics</codeph>.
+                </p>
+
+                <p>
+                  <note>
+                    Replace <varname>hostname</varname> and <varname>port</varname> with the hostname and port of
+                    your Impala state store host machine and web server port. The default port is 25010.
+                  </note>
+                  The number of <codeph>impalad</codeph> instances listed should match the expected number of
+                  <codeph>impalad</codeph> instances installed in the cluster. There should also be one
+                  <codeph>impalad</codeph> instance installed on each DataNode
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  Ensure Impala is installed on all DataNodes. Start any <codeph>impalad</codeph> instances that
+                  are not running.
+                </p>
+              </entry>
+            </row>
+            <row>
+              <entry>
+                <p>
+                  Queries are slow to return results.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  Impala may not be configured to use native checksumming. Native checksumming uses
+                  machine-specific instructions to compute checksums over HDFS data very quickly. Review Impala
+                  logs. If you find instances of "<codeph>INFO util.NativeCodeLoader: Loaded the
+                  native-hadoop</codeph>" messages, native checksumming is not enabled.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  Ensure Impala is configured to use native checksumming as described in
+                  <xref href="impala_config_performance.xml#config_performance"/>.
+                </p>
+              </entry>
+            </row>
+            <row>
+              <entry>
+                <p>
+                  Queries are slow to return results.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  Impala may not be configured to use data locality tracking.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  Test Impala for data locality tracking and make configuration changes as necessary. Information
+                  on this process can be found in <xref href="impala_config_performance.xml#config_performance"/>.
+                </p>
+              </entry>
+            </row>
+            <row>
+              <entry>
+                <p>
+                  Attempts to complete Impala tasks such as executing INSERT-SELECT actions fail. The Impala logs
+                  include notes that files could not be opened due to permission denied.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  This can be the result of permissions issues. For example, you could use the Hive shell as the
+                  hive user to create a table. After creating this table, you could attempt to complete some
+                  action, such as an INSERT-SELECT on the table. Because the table was created using one user and
+                  the INSERT-SELECT is attempted by another, this action may fail due to permissions issues.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  In general, ensure the Impala user has sufficient permissions. In the preceding example, ensure
+                  the Impala user has sufficient permissions to the table that the Hive user created.
+                </p>
+              </entry>
+            </row>
+            <row rev="IMP-1210">
+              <entry>
+                <p>
+                  Impala fails to start up, with the <cmdname>impalad</cmdname> logs referring to errors connecting
+                  to the statestore service and attempts to re-register.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  A large number of databases, tables, partitions, and so on can require metadata synchronization,
+                  particularly on startup, that takes longer than the default timeout for the statestore service.
+                </p>
+              </entry>
+              <entry>
+                <p>
+                  Configure the statestore timeout value and possibly other settings related to the frequency of
+                  statestore updates and metadata loading. See
+                  <xref href="impala_timeouts.xml#statestore_timeout"/> and
+                  <xref href="impala_scalability.xml#statestore_scalability"/>.
+                </p>
+              </entry>
+            </row>
+          </tbody>
+        </tgroup>
+      </table>
+
+      <p audience="Cloudera">
+        Some or all of these settings might also be useful.
+<codeblock>NUM_SCANNER_THREADS: 0
+ABORT_ON_DEFAULT_LIMIT_EXCEEDED: 0
+MAX_IO_BUFFERS: 0
+DEFAULT_ORDER_BY_LIMIT: -1
+BATCH_SIZE: 0
+NUM_NODES: 0
+DISABLE_CODEGEN: 0
+MAX_ERRORS: 0
+ABORT_ON_ERROR: 0
+MAX_SCAN_RANGE_LENGTH: 0
+ALLOW_UNSUPPORTED_FORMATS: 0
+SUPPORT_START_OVER: false
+DEBUG_ACTION:
+MEM_LIMIT: 0
+</codeblock>
+      </p>
+    </conbody>
+  </concept>
+
+  <concept audience="Cloudera" id="core_dumps">
+
+    <title>Enabling Core Dumps for Impala</title>
+
+    <conbody>
+
+        <p>
+          Fill in details, then unhide.
+        </p>
+
+        <p>
+          From Nong:
+        </p>
+
+        <p>
+          In a CM-managed cluster, search for "core" from the impala configuration page. You should see the "enable
+          core dump" config.
+        </p>
+
+        <p>
+          From <xref href="impala_config_options.xml#config_options"/>:
+        </p>
+
+<codeblock>export ENABLE_CORE_DUMPS=${ENABLE_COREDUMPS:-false}</codeblock>
+
+        <note conref="../shared/impala_common.xml#common/core_dump_considerations"/>
+
+      <p></p>
+    </conbody>
+  </concept>
+
+  <concept audience="Cloudera" id="io_throughput">
+    <title>Verifying I/O Throughput</title>
+    <conbody>
+      <p>
+        Optimal Impala query performance depends on being able to perform I/O across multiple storage devices
+        in parallel, with the data transferred at or close to the maximum throughput for each device.
+        If a hardware or configuration issue causes a reduction in I/O throughput, even if the problem only
+        affects a subset of storage devices, you might experience
+        slow query performance that cannot be improved by using regular SQL tuning techniques.
+      </p>
+      <p>
+        As a general guideline, expect each commodity storage device (for example, a standard rotational
+        hard drive) to be able to transfer approximately 100 MB per second. If you see persistent slow query
+        perormance, examine the Impala logs to check
+      </p>
+
+<codeblock>
+<![CDATA[
+Useful test from beta at Visa.
+SME: Jayant@
+
+Symptoms:
+* Queries running slow
+* Scan rate of IO in Impala logs show noticeably less than expected IO rate for each disk (typical commodity disk should provide ~100 MB/s
+
+Actions:
+* Validate disk read from OS to confirm no issue at hardware or OS level
+* Validate disk read at HDFS to see if issue at HDFS config
+
+Specifics:
+Testing Linux and hardware IO:
+# First running:
+sudo sysctl -w vm.drop_caches=3 vm.drop_caches=0
+
+# Then Running:
+sudo dd if=/dev/sda bs=1M of=/dev/null count=1k
+& sudo dd if=/dev/sdb bs=1M of=/dev/null count=1k
+& sudo dd if=/dev/sdc bs=1M of=/dev/null count=1k
+& sudo dd if=/dev/sdd bs=1M of=/dev/null count=1k & wait
+
+Testing HDFS IO:
+# You can use TestDFSIO. Its documented here ; http://answers.oreilly.com/topic/460-how-to-benchmark-a-hadoop-cluster/
+# You can also use sar, dd and iostat for monitoring the disk.
+
+# writes 10 files each of 1000 MB
+hadoop jar $HADOOP_INSTALL/hadoop-*-test.jar TestDFSIO -write -nrFiles 10 -fileSize 1000
+
+# run the read benchmark
+hadoop jar $HADOOP_INSTALL/hadoop-*-test.jar TestDFSIO -read -nrFiles 10 -fileSize 1000
+
+# clean up the data
+hadoop jar $HADOOP_INSTALL/hadoop-*-test.jar TestDFSIO -clean
+]]>
+</codeblock>
+
+    </conbody>
+  </concept>
+
+  <concept id="webui_snippet" audience="PDF">
+    <title conref="impala_webui.xml#webui/webui_title"/>
+    <conbody>
+      <p conref="impala_webui.xml#webui/webui_intro"/>
+      <p>
+        For full details, see <xref href="impala_webui.xml#webui"/>.
+      </p>
+    </conbody>
+  </concept>
+
+</concept>

http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/1fcc8cee/docs/topics/impala_webui.xml
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diff --git a/docs/topics/impala_webui.xml b/docs/topics/impala_webui.xml
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+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
+<concept id="webui">
+
+  <title id="webui_title">Impala Web User Interface for Debugging</title>
+  <titlealts audience="PDF"><navtitle>Web User Interface</navtitle></titlealts>
+  <prolog>
+    <metadata>
+      <data name="Category" value="Impala"/>
+      <data name="Category" value="Troubleshooting"/>
+      <data name="Category" value="Administrators"/>
+      <data name="Category" value="Developers"/>
+      <data name="Category" value="Data Analysts"/>
+    </metadata>
+  </prolog>
+
+  <conbody>
+
+    <p id="webui_intro">
+      <indexterm audience="Cloudera">web UI</indexterm>
+      <indexterm audience="Cloudera">debug UI</indexterm>
+      Each of the Impala daemons (<cmdname>impalad</cmdname>, <cmdname>statestored</cmdname>,
+      and <cmdname>catalogd</cmdname>) includes a built-in web server that displays
+      diagnostic and status information:
+      <ul>
+      <li>
+        <p>
+          The <cmdname>impalad</cmdname> web UI (default port: 25000) includes
+          information about configuration settings, running and completed queries, and associated performance and
+          resource usage for queries. In particular, the <uicontrol>Details</uicontrol> link for each query displays
+          alternative views of the query including a graphical representation of the plan, and the
+          output of the <codeph>EXPLAIN</codeph>, <codeph>SUMMARY</codeph>, and <codeph>PROFILE</codeph>
+          statements from <cmdname>impala-shell</cmdname>.
+          Each host that runs the <cmdname>impalad</cmdname> daemon has
+          its own instance of the web UI, with details about those queries for which that
+          host served as the coordinator. To get a consolidated view for all queries,
+          it is usually more convenient to use the charts, graphs, and other monitoring
+          features in Cloudera Manager. The <cmdname>impalad</cmdname> web UI is mainly
+          for diagnosing query problems that can be traced to a particular node.
+        </p>
+      </li>
+      <li>
+        <p>
+          The <cmdname>statestored</cmdname> web UI (default port: 25010) includes
+          information about memory usage, configuration settings, and ongoing health checks
+          performed by this daemon. Because there is only a single instance of this
+          daemon within any cluster, you view the web UI only on the particular host
+          that serves as the Impala Statestore.
+        </p>
+      </li>
+      <li>
+        <p>
+          The <cmdname>catalogd</cmdname> web UI (default port: 25020) includes
+          information about the databases, tables, and other objects managed by Impala,
+          in addition to the resource usage and configuration settings of the daemon itself.
+          The catalog information is represented as the underlying Thrift data structures.
+          Because there is only a single instance of this daemon within any cluster, you view the
+          web UI only on the particular host that serves as the Impala Catalog Server.
+        </p>
+      </li>
+      </ul>
+    </p>
+
+    <note>
+      <p>
+        The web user interface is primarily for problem diagnosis and troubleshooting. The items listed and their
+        formats are subject to change. To monitor Impala health, particularly across the entire cluster at once, use
+        the Cloudera Manager interface.
+      </p>
+    </note>
+
+    <p outputclass="toc inpage"/>
+  </conbody>
+
+  <concept id="webui_impalad">
+
+    <title>Debug Web UI for impalad</title>
+
+    <conbody>
+
+      <p>
+        To debug and troubleshoot the <cmdname>impalad</cmdname> daemon using a web-based interface, open the URL
+        <codeph>http://<varname>impala-server-hostname</varname>:25000/</codeph> in a browser. (For secure
+        clusters, use the prefix <codeph>https://</codeph> instead of <codeph>http://</codeph>.) Because each
+        Impala node produces its own set of debug information, choose a specific node that you are curious about or
+        suspect is having problems.
+      </p>
+
+      <note>
+        To get a convenient picture of the health of all Impala nodes in a cluster, use the Cloudera Manager
+        interface, which collects the low-level operational information from all Impala nodes, and presents a
+        unified view of the entire cluster.
+      </note>
+    </conbody>
+
+    <concept audience="Cloudera" id="webui_impalad_disabling">
+
+      <title>Turning off the Web UI for impalad</title>
+
+      <conbody>
+
+        <p></p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_impalad_main">
+
+      <title>Main Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the main page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25000/</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25000/</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page lists the version of the <cmdname>impalad</cmdname> daemon, plus basic hardware and software
+          information about the corresponding host, such as information about the CPU, memory, disks, and operating
+          system version.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_impalad_backends">
+
+      <title>Backends Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>backends</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25000/backends</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25000/backends</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page lists the host and port info for each of the <cmdname>impalad</cmdname> nodes in the cluster.
+          Because each <cmdname>impalad</cmdname> daemon knows about every other <cmdname>impalad</cmdname> daemon
+          through the statestore, this information should be the same regardless of which node you select. Links
+          take you to the corresponding debug web pages for any of the other nodes in the cluster.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_impalad_catalog">
+
+      <title>Catalog Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>catalog</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25000/catalog</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25000/catalog</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays a list of databases and associated tables recognized by this instance of
+          <cmdname>impalad</cmdname>. You can use this page to locate which database a table is in, check the
+          exact spelling of a database or table name, look for identical table names in multiple databases, and so
+          on.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_impalad_logs">
+
+      <title>Logs Page</title>
+  <prolog>
+    <metadata>
+      <data name="Category" value="Logs"/>
+    </metadata>
+  </prolog>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>logs</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25000/logs</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25000/logs</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page shows the last portion of the <filepath>impalad.INFO</filepath> log file, the most detailed of
+          the info, warning, and error logs for the <cmdname>impalad</cmdname> daemon. You can refer here to see
+          the details of the most recent operations, whether the operations succeeded or encountered errors. This
+          central page can be more convenient than looking around the filesystem for the log files, which could be
+          in different locations on clusters that use Cloudera Manager or not.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_impalad_memz">
+
+      <title>Memz Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>memz</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25000/memz</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25000/memz</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays summary and detailed information about memory usage by the <cmdname>impalad</cmdname>
+          daemon. You can see the memory limit in effect for the node, and how much of that memory Impala is
+          currently using.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_impalad_metrics">
+
+      <title>Metrics Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>metrics</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25000/metrics</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25000/metrics</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays the current set of metrics: counters and flags representing various aspects of
+          <cmdname>impalad</cmdname> internal operation. For the meanings of these metrics, see
+          <xref href="http://www.cloudera.com/documentation/enterprise/latest/topics/cm_metrics_impala.html" scope="external" format="html">Impala
+          Metrics</xref> in the Cloudera Manager documentation.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_impalad_queries">
+
+      <title>Queries Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>queries</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25000/queries</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25000/queries</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page lists all currently running queries, plus any completed queries whose details still reside in
+          memory. The queries are listed in reverse chronological order, with the most recent at the top. (You can
+          control the amount of memory devoted to completed queries by specifying the
+          <codeph>--query_log_size</codeph> startup option for <cmdname>impalad</cmdname>.)
+        </p>
+
+        <p>
+          On this page, you can see at a glance how many SQL statements are failing (<codeph>State</codeph> value
+          of <codeph>EXCEPTION</codeph>), how large the result sets are (<codeph># rows fetched</codeph>), and how
+          long each statement took (<codeph>Start Time</codeph> and <codeph>End Time</codeph>).
+        </p>
+
+        <p>
+          Each query has an associated link that displays the detailed query profile, which you can examine to
+          understand the performance characteristics of that query. See
+          <xref href="impala_explain_plan.xml#perf_profile"/> for details.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_impalad_sessions">
+
+      <title>Sessions Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>sessions</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25000/sessions</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25000/sessions</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays information about the sessions currently connected to this <cmdname>impalad</cmdname>
+          instance. For example, sessions could include connections from the <cmdname>impala-shell</cmdname>
+          command, JDBC or ODBC applications, or the Impala Query UI in the Hue web interface.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_impalad_threadz">
+
+      <title>Threadz Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>threadz</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25000/threadz</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25000/threadz</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays information about the threads used by this instance of <cmdname>impalad</cmdname>,
+          and shows which categories they are grouped into. Making use of this information requires substantial
+          knowledge about Impala internals.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_impalad_varz">
+
+      <title>Varz Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>varz</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25000/varz</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25000/varz</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page shows the configuration settings in effect when this instance of <cmdname>impalad</cmdname>
+          communicates with other Hadoop components such as HDFS and YARN. These settings are collected from a set
+          of configuration files; Impala might not actually make use of all settings.
+        </p>
+
+        <p>
+          The bottom of this page also lists all the command-line settings in effect for this instance of
+          <cmdname>impalad</cmdname>. See <xref href="impala_config_options.xml#config_options"/> for information
+          about modifying these values.
+        </p>
+      </conbody>
+    </concept>
+  </concept>
+
+  <concept audience="Cloudera" id="webui_statestored">
+
+    <title>Debug Web UI for statestored</title>
+
+    <conbody>
+
+      <p></p>
+    </conbody>
+
+    <concept audience="Cloudera" id="webui_statestored_disabling">
+
+      <title>Turning off the Web UI for statestored</title>
+
+      <conbody>
+
+        <p></p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_statestored_main">
+
+      <title>Main Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the main page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25010/</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25010/</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page lists the version of the <cmdname>impalad</cmdname> daemon, plus basic hardware and software
+          information about the corresponding host, such as information about the CPU, memory, disks, and operating
+          system version.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_statestored_logs">
+
+      <title>Logs Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>logs</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25010/logs</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25010/logs</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page shows the last portion of the <filepath>impalad.INFO</filepath> log file, the most detailed of
+          the info, warning, and error logs for the <cmdname>impalad</cmdname> daemon. You can refer here to see
+          the details of the most recent operations, whether the operations succeeded or encountered errors. This
+          central page can be more convenient than looking around the filesystem for the log files, which could be
+          in different locations on clusters that use Cloudera Manager or not.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_statestored_memz">
+
+      <title>Memz Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>memz</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25010/memz</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25010/memz</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays summary and detailed information about memory usage by the <cmdname>impalad</cmdname>
+          daemon. You can see the memory limit in effect for the node, and how much of that memory Impala is
+          currently using.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_statestored_metrics">
+
+      <title>Metrics Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>metrics</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25010/metrics</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25010/metrics</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays the current set of metrics: counters and flags representing various aspects of
+          <cmdname>impalad</cmdname> internal operation. For the meanings of these metrics, see
+          <xref href="http://www.cloudera.com/documentation/enterprise/latest/topics/cm_metrics_impala.html" scope="external" format="html">Impala
+          Metrics</xref> in the Cloudera Manager documentation.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_statestored_subscribers">
+
+      <title>Subscribers Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>subscribers</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25010/subscribers</codeph> (non-secure cluster)
+          or <codeph>https://<varname>impala-server-hostname</varname>:25010/subscribers</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays information about...
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_statestored_threadz">
+
+      <title>Threadz Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>threadz</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25010/threadz</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25010/threadz</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays information about the threads used by this instance of <cmdname>impalad</cmdname>,
+          and shows which categories they are grouped into. Making use of this information requires substantial
+          knowledge about Impala internals.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_statestored_topics">
+
+      <title>Topics Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>topics</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25010/topics</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25010/topics</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays information about...
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_statestored_varz">
+
+      <title>Varz Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>varz</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25010/varz</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25010/varz</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page shows the configuration settings in effect when this instance of <cmdname>impalad</cmdname>
+          communicates with other Hadoop components such as HDFS and YARN. These settings are collected from a set
+          of configuration files; Impala might not actually make use of all settings.
+        </p>
+
+        <p>
+          The bottom of this page also lists all the command-line settings in effect for this instance of
+          <cmdname>impalad</cmdname>. See <xref href="impala_config_options.xml#config_options"/> for information
+          about modifying these values.
+        </p>
+      </conbody>
+    </concept>
+  </concept>
+
+  <concept audience="Cloudera" id="webui_catalogd">
+
+    <title>Debug Web UI for catalogd</title>
+
+    <conbody>
+
+      <p></p>
+    </conbody>
+
+    <concept audience="Cloudera" id="webui_catalogd_disabling">
+
+      <title>Turning off the Web UI for impalad</title>
+
+      <conbody>
+
+        <p></p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_catalogd_main">
+
+      <title>Main Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the main page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25020/</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25020/</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page lists the version of the <cmdname>impalad</cmdname> daemon, plus basic hardware and software
+          information about the corresponding host, such as information about the CPU, memory, disks, and operating
+          system version.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_catalogd_catalog">
+
+      <title>Catalog Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>catalog</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25020/catalog</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25020/catalog</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays a list of databases and associated tables recognized by this instance of
+          <cmdname>impalad</cmdname>. You can use this page to locate which database a table is in, check the
+          exact spelling of a database or table name, look for identical table names in multiple databases, and so
+          on.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_catalogd_logs">
+
+      <title>Logs Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>logs</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25020/logs</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25020/logs</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page shows the last portion of the <filepath>impalad.INFO</filepath> log file, the most detailed of
+          the info, warning, and error logs for the <cmdname>impalad</cmdname> daemon. You can refer here to see
+          the details of the most recent operations, whether the operations succeeded or encountered errors. This
+          central page can be more convenient than looking around the filesystem for the log files, which could be
+          in different locations on clusters that use Cloudera Manager or not.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_catalogd_metrics">
+
+      <title>Metrics Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>metrics</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25020/metrics</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25020/metrics</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page displays the current set of metrics: counters and flags representing various aspects of
+          <cmdname>impalad</cmdname> internal operation. For the meanings of these metrics, see
+          <xref href="http://www.cloudera.com/documentation/enterprise/latest/topics/cm_metrics_impala.html" scope="external" format="html">Impala
+          Metrics</xref> in the Cloudera Manager documentation.
+        </p>
+      </conbody>
+    </concept>
+
+    <concept id="webui_catalogd_varz">
+
+      <title>Varz Page</title>
+
+      <conbody>
+
+        <p>
+          By default, the <uicontrol>varz</uicontrol> page of the debug web UI is at
+          <codeph>http://<varname>impala-server-hostname</varname>:25020/varz</codeph> (non-secure cluster) or
+          <codeph>https://<varname>impala-server-hostname</varname>:25020/varz</codeph> (secure cluster).
+        </p>
+
+        <p>
+          This page shows the configuration settings in effect when this instance of <cmdname>impalad</cmdname>
+          communicates with other Hadoop components such as HDFS and YARN. These settings are collected from a set
+          of configuration files; Impala might not actually make use of all settings.
+        </p>
+
+        <p>
+          The bottom of this page also lists all the command-line settings in effect for this instance of
+          <cmdname>impalad</cmdname>. See <xref href="impala_config_options.xml#config_options"/> for information
+          about modifying these values.
+        </p>
+      </conbody>
+    </concept>
+  </concept>
+</concept>


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