You are viewing a plain text version of this content. The canonical link for it is here.
Posted to jira@kafka.apache.org by "ASF GitHub Bot (JIRA)" <ji...@apache.org> on 2018/10/28 18:32:00 UTC
[jira] [Commented] (KAFKA-7524) Recommend Scala 2.12 and use it for
development
[ https://issues.apache.org/jira/browse/KAFKA-7524?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16666516#comment-16666516 ]
ASF GitHub Bot commented on KAFKA-7524:
---------------------------------------
ijuma closed pull request #5530: KAFKA-7524: Recommend Scala 2.12 and use it for development
URL: https://github.com/apache/kafka/pull/5530
This is a PR merged from a forked repository.
As GitHub hides the original diff on merge, it is displayed below for
the sake of provenance:
As this is a foreign pull request (from a fork), the diff is supplied
below (as it won't show otherwise due to GitHub magic):
diff --git a/README.md b/README.md
index 4e8c149de55..f12b10f1233 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,9 @@ You need to have [Gradle](http://www.gradle.org/installation) and [Java](http://
Kafka requires Gradle 4.7 or higher.
-Java 8 should be used for building in order to support both Java 8 and Java 10 at runtime.
+Java 8 should be used for building in order to support both Java 8 and Java 11 at runtime.
+
+Scala 2.12 is used by default, see below for how to use a different Scala version or all of the supported Scala versions.
### First bootstrap and download the wrapper ###
cd kafka_source_dir
@@ -64,26 +66,33 @@ Generate coverage for a single module, i.e.:
./gradlew clients:reportCoverage
### Building a binary release gzipped tar ball ###
- ./gradlew clean
- ./gradlew releaseTarGz
+ ./gradlew clean releaseTarGz
The above command will fail if you haven't set up the signing key. To bypass signing the artifact, you can run:
- ./gradlew releaseTarGz -x signArchives
+ ./gradlew clean releaseTarGz -x signArchives
The release file can be found inside `./core/build/distributions/`.
### Cleaning the build ###
./gradlew clean
-### Running a task on a particular version of Scala (either 2.11.x or 2.12.x) ###
-*Note that if building the jars with a version other than 2.11.12, you need to set the `SCALA_VERSION` variable or change it in `bin/kafka-run-class.sh` to run the quick start.*
+### Running a task with a particular version of Scala (either 2.11.x or 2.12.x) ###
+*Note that if building the jars with a version other than 2.12.x, you need to set the `SCALA_VERSION` variable or change it in `bin/kafka-run-class.sh` to run the quick start.*
+
+You can pass either the major version (eg 2.12) or the full version (eg 2.12.7):
+
+ ./gradlew -PscalaVersion=2.12 jar
+ ./gradlew -PscalaVersion=2.12 test
+ ./gradlew -PscalaVersion=2.12 releaseTarGz
-You can pass either the major version (eg 2.11) or the full version (eg 2.11.12):
+### Running a task with all scala versions ###
- ./gradlew -PscalaVersion=2.11 jar
- ./gradlew -PscalaVersion=2.11 test
- ./gradlew -PscalaVersion=2.11 releaseTarGz
+Append `All` to the task name:
+
+ ./gradlew testAll
+ ./gradlew jarAll
+ ./gradlew releaseTarGzAll
### Running a task for a specific project ###
This is for `core`, `examples` and `clients`
@@ -104,15 +113,6 @@ The `eclipse` task has been configured to use `${project_dir}/build_eclipse` as
build directory (`${project_dir}/bin`) clashes with Kafka's scripts directory and we don't use Gradle's build directory
to avoid known issues with this configuration.
-### Building the jar for all scala versions and for all projects ###
- ./gradlew jarAll
-
-### Running unit/integration tests for all scala versions and for all projects ###
- ./gradlew testAll
-
-### Building a binary release gzipped tar ball for all scala versions ###
- ./gradlew releaseTarGzAll
-
### Publishing the jar for all version of Scala and for all projects to maven ###
./gradlew uploadArchivesAll
diff --git a/bin/kafka-run-class.sh b/bin/kafka-run-class.sh
index eed39557f9c..88698a5367c 100755
--- a/bin/kafka-run-class.sh
+++ b/bin/kafka-run-class.sh
@@ -48,7 +48,7 @@ should_include_file() {
base_dir=$(dirname $0)/..
if [ -z "$SCALA_VERSION" ]; then
- SCALA_VERSION=2.11.12
+ SCALA_VERSION=2.12.7
fi
if [ -z "$SCALA_BINARY_VERSION" ]; then
diff --git a/bin/windows/kafka-run-class.bat b/bin/windows/kafka-run-class.bat
index 1dfd9a5abfe..750db07f024 100755
--- a/bin/windows/kafka-run-class.bat
+++ b/bin/windows/kafka-run-class.bat
@@ -27,7 +27,7 @@ set BASE_DIR=%CD%
popd
IF ["%SCALA_VERSION%"] EQU [""] (
- set SCALA_VERSION=2.11.12
+ set SCALA_VERSION=2.12.7
)
IF ["%SCALA_BINARY_VERSION%"] EQU [""] (
diff --git a/docs/api.html b/docs/api.html
index ea511b44453..4545e9b9586 100644
--- a/docs/api.html
+++ b/docs/api.html
@@ -81,12 +81,12 @@ <h3><a id="streamsapi" href="#streamsapi">2.3 Streams API</a></h3>
<p>
When using Scala you may optionally include the <code>kafka-streams-scala</code> library. Additional documentation on using the Kafka Streams DSL for Scala is available <a href="/{{version}}/documentation/streams/developer-guide/dsl-api.html#scala-dsl">in the developer guide</a>.
<p>
- To use Kafka Streams DSL for Scala for Scala 2.11 you can use the following maven dependency:
+ To use Kafka Streams DSL for Scala for Scala {{scalaVersion}} you can use the following maven dependency:
<pre class="brush: xml;">
<dependency>
<groupId>org.apache.kafka</groupId>
- <artifactId>kafka-streams-scala_2.11</artifactId>
+ <artifactId>kafka-streams-scala_{{scalaVersion}}</artifactId>
<version>{{fullDotVersion}}</version>
</dependency>
</pre>
diff --git a/docs/js/templateData.js b/docs/js/templateData.js
index eae0b30a067..f40542bb433 100644
--- a/docs/js/templateData.js
+++ b/docs/js/templateData.js
@@ -20,5 +20,5 @@ var context={
"version": "21",
"dotVersion": "2.1",
"fullDotVersion": "2.1.0",
- "scalaVersion": "2.11"
+ "scalaVersion": "2.12"
};
diff --git a/docs/quickstart.html b/docs/quickstart.html
index e709cc736f4..6a88241c24b 100644
--- a/docs/quickstart.html
+++ b/docs/quickstart.html
@@ -25,11 +25,11 @@
<h4><a id="quickstart_download" href="#quickstart_download">Step 1: Download the code</a></h4>
-<a href="https://www.apache.org/dyn/closer.cgi?path=/kafka/{{fullDotVersion}}/kafka_2.11-{{fullDotVersion}}.tgz" title="Kafka downloads">Download</a> the {{fullDotVersion}} release and un-tar it.
+<a href="https://www.apache.org/dyn/closer.cgi?path=/kafka/{{fullDotVersion}}/kafka_{{scalaVersion}}-{{fullDotVersion}}.tgz" title="Kafka downloads">Download</a> the {{fullDotVersion}} release and un-tar it.
<pre class="brush: bash;">
-> tar -xzf kafka_2.11-{{fullDotVersion}}.tgz
-> cd kafka_2.11-{{fullDotVersion}}
+> tar -xzf kafka_{{scalaVersion}}-{{fullDotVersion}}.tgz
+> cd kafka_{{scalaVersion}}-{{fullDotVersion}}
</pre>
<h4><a id="quickstart_startserver" href="#quickstart_startserver">Step 2: Start the server</a></h4>
diff --git a/docs/streams/developer-guide/dsl-api.html b/docs/streams/developer-guide/dsl-api.html
index 4b91eaa86b3..c40d6cedb0a 100644
--- a/docs/streams/developer-guide/dsl-api.html
+++ b/docs/streams/developer-guide/dsl-api.html
@@ -3414,11 +3414,11 @@ <h4><a id="streams_concepts_globalktable" href="#streams_concepts_globalktable">
<li><code class="docutils literal"><span class="pre">org.apache.kafka.streams.scala.ImplicitConversions</span></code>: Module that brings into scope the implicit conversions between the Scala and Java classes.</li>
<li><code class="docutils literal"><span class="pre">org.apache.kafka.streams.scala.Serdes</span></code>: Module that contains all primitive SerDes that can be imported as implicits and a helper to create custom SerDes.</li>
</ul>
- <p>The library is cross-built with Scala 2.11 and 2.12. To reference the library compiled against Scala 2.11 include the following in your maven <code>pom.xml</code> add the following:</p>
+ <p>The library is cross-built with Scala 2.11 and 2.12. To reference the library compiled against Scala {{scalaVersion}} include the following in your maven <code>pom.xml</code> add the following:</p>
<pre class="brush: xml;">
<dependency>
<groupId>org.apache.kafka</groupId>
- <artifactId>kafka-streams-scala_2.11</artifactId>
+ <artifactId>kafka-streams-scala_{{scalaVersion}}</artifactId>
<version>{{fullDotVersion}}</version>
</dependency>
</pre>
diff --git a/docs/streams/developer-guide/write-streams.html b/docs/streams/developer-guide/write-streams.html
index 145eb307a4f..ad320fadd93 100644
--- a/docs/streams/developer-guide/write-streams.html
+++ b/docs/streams/developer-guide/write-streams.html
@@ -101,10 +101,10 @@
<artifactId>kafka-clients</artifactId>
<version>{{fullDotVersion}}</version>
</dependency>
-<!-- Optionally include Kafka Streams DSL for Scala for Scala 2.11 -->
+<!-- Optionally include Kafka Streams DSL for Scala for Scala {{scalaVersion}} -->
<dependency>
<groupId>org.apache.kafka</groupId>
- <artifactId>kafka-streams-scala_2.11</artifactId>
+ <artifactId>kafka-streams-scala_{{scalaVersion}}</artifactId>
<version>{{fullDotVersion}}</version>
</dependency>
</pre>
diff --git a/gradle.properties b/gradle.properties
index 3e3dbfac4c3..d63d3e373e2 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -20,6 +20,6 @@ group=org.apache.kafka
# - tests/kafkatest/version.py (variable DEV_VERSION)
# - kafka-merge-pr.py.
version=2.2.0-SNAPSHOT
-scalaVersion=2.11.12
+scalaVersion=2.12.7
task=build
org.gradle.jvmargs=-Xmx1024m -Xss2m
diff --git a/release.py b/release.py
index d91f535904c..8e2624e9282 100755
--- a/release.py
+++ b/release.py
@@ -245,7 +245,7 @@ def command_stage_docs():
cmd("Building docs", "./gradlew -Pversion=%s clean releaseTarGzAll aggregatedJavadoc" % gradle_version_override, cwd=REPO_HOME, env=jdk8_env)
- docs_tar = os.path.join(REPO_HOME, 'core', 'build', 'distributions', 'kafka_2.11-%s-site-docs.tgz' % gradle_version_override)
+ docs_tar = os.path.join(REPO_HOME, 'core', 'build', 'distributions', 'kafka_2.12-%s-site-docs.tgz' % gradle_version_override)
versioned_docs_path = os.path.join(kafka_site_repo_path, docs_version(version))
if not os.path.exists(versioned_docs_path):
@@ -641,8 +641,8 @@ def select_gpg_key():
Some suggested steps:
* Grab the source archive and make sure it compiles: http://home.apache.org/~%(apache_id)s/kafka-%(rc_tag)s/kafka-%(release_version)s-src.tgz
- * Grab one of the binary distros and run the quickstarts against them: http://home.apache.org/~%(apache_id)s/kafka-%(rc_tag)s/kafka_2.11-%(release_version)s.tgz
- * Extract and verify one of the site docs jars: http://home.apache.org/~%(apache_id)s/kafka-%(rc_tag)s/kafka_2.11-%(release_version)s-site-docs.tgz
+ * Grab one of the binary distros and run the quickstarts against them: http://home.apache.org/~%(apache_id)s/kafka-%(rc_tag)s/kafka_2.12-%(release_version)s.tgz
+ * Extract and verify one of the site docs jars: http://home.apache.org/~%(apache_id)s/kafka-%(rc_tag)s/kafka_2.12-%(release_version)s-site-docs.tgz
* Build a sample against jars in the staging repo: (TODO: Can we get a temporary URL before "closing" the staged artifacts?)
* Validate GPG signatures on at least one file:
wget http://home.apache.org/~%(apache_id)s/kafka-%(rc_tag)s/kafka-%(release_version)s-src.tgz &&
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
users@infra.apache.org
> Recommend Scala 2.12 and use it for development
> -----------------------------------------------
>
> Key: KAFKA-7524
> URL: https://issues.apache.org/jira/browse/KAFKA-7524
> Project: Kafka
> Issue Type: Improvement
> Reporter: Ismael Juma
> Assignee: Ismael Juma
> Priority: Major
> Fix For: 2.2.0
>
>
> Scala 2.12 has better support for newer Java versions and includes additional compiler warnings that are helpful during development. In addition, Scala 2.11 hasn't been supported by the Scala community for a long time, the soon to be released Spark 2.4.0 will finally support Scala 2.12 (this was the main reason preventing many from upgrading to Scala 2.12) and Scala 2.13 is at the RC stage. It's time to start recommending the Scala 2.12 build as we prepare support for Scala 2.13 and start thinking about removing support for Scala 2.11.
> In the meantime, Jenkins will continue to build all supported Scala versions (including Scala 2.11) so the PR and trunk jobs will fail if people accidentally use methods introduced in Scala 2.12.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)