ndimiduk commented on a change in pull request #1871:
URL: https://github.com/apache/hbase/pull/1871#discussion_r437707270
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File path: src/main/asciidoc/_chapters/developer.adoc
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@@ -397,28 +396,109 @@ mvn clean install -DskipTests
See the <<hbase.unittests.cmds,hbase.unittests.cmds>> section in
<<hbase.unittests,hbase.unittests>>
[[maven.build.hadoop]]
-==== Building against various hadoop versions.
+==== Building against various Hadoop versions
+
+HBase supports building against Apache Hadoop versions: 2.y and 3.y (early
release artifacts).
+Exactly which version of Hadoop is used by default varies by release branch.
See the section
+<<hadoop,Hadoop>> for the complete breakdown of supported Hadoop version by
HBase release.
+
+The mechanism for selecting a Hadoop version at build time is identical across
all releases. Which
+version of Hadoop is default varies. We manage Hadoop major version selection
by way of Maven
+profiles. Due to the peculiarities of Maven profile mutual exclusion, the
profile that builds
+against a particular Hadoop version is activated by setting a property, *not*
the usual profile
+activation. Hadoop version profile activation is summarized by the following
table.
+
+.Hadoop Profile Activation by HBase Release
+[cols="3*^.^", options="header"]
+|===
+| | Hadoop2 Activation | Hadoop3 Activation
+| HBase 1.3+ | _active by default_ | `-Dhadoop.profile=3.0`
+| HBase 3.0+ | _not supported_ | _active by default_
+|===
+
+[WARNING]
+====
+Please note that where a profile is active by default, `hadoop.profile` must
NOT be provided.
+====
+
+Once the Hadoop major version profile is activated, the exact Hadoop version
can be
+specified by overriding the appropriate property value. For Hadoop2 versions,
the property name
+is `hadoop-two.version`. With Hadoop3 versions, the property name is
`hadoop-three.version`.
-HBase supports building against Apache Hadoop versions: 2.y and 3.y (early
release artifacts). By default we build against Hadoop 2.x.
+.Example 1, Building HBase 1.7 against Hadoop 2.10.0
-To build against a specific release from the Hadoop 2.y line, set e.g.
`-Dhadoop-two.version=2.6.3`.
+For example, to build HBase 1.7 against Hadoop 2.10.0, the profile is set for
Hadoop2 by default,
+so only `hadoop-two.version` must be specified:
[source,bourne]
----
-mvn -Dhadoop-two.version=2.6.3 ...
+git checkout branch-1
+mvn -Dhadoop-two.version=2.10.0 ...
----
-To change the major release line of Hadoop we build against, add a
hadoop.profile property when you invoke +mvn+:
+.Example 2, Building HBase 2.3 against Hadoop 3.3.0-SNAPSHOT
Review comment:
@busbey updated the language around the SNAPSHOT dependency, let me know
if this satisfies.
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