src/doc/4.0-rc2/_sources/new/java11.rst.txt - cassandra-website - Git at Google

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 .. distributed with this work for additional information
 .. regarding copyright ownership.  The ASF licenses this file
 .. to you under the Apache License, Version 2.0 (the
 .. "License"); you may not use this file except in compliance
 .. with the License.  You may obtain a copy of the License at
 ..
 ..     http://www.apache.org/licenses/LICENSE-2.0
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 .. Unless required by applicable law or agreed to in writing, software
 .. distributed under the License is distributed on an "AS IS" BASIS,
 .. WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 .. See the License for the specific language governing permissions and
 .. limitations under the License.

 Support for Java 11
 -------------------

 In the new Java release cadence a new Java version is made available every six months. The more frequent release cycle
 is favored as it brings new Java features to the developers as and when they are developed without the wait that the
 earlier 3 year release model incurred.  Not every Java version is a Long Term Support (LTS) version. After Java 8 the
 next LTS version is Java 11. Java 9, 10, 12 and 13 are all non-LTS versions.

 One of the objectives of the Apache Cassandra 4.0 version is to support the recent LTS Java versions 8 and 11 (`CASSANDRA-9608
 <https://issues.apache.org/jira/browse/CASSANDRA-9608>`_). Java 8 and
 Java 11 may be used to build and run Apache Cassandra 4.0.

 **Note**: Support for JDK 11 in Apache Cassandra 4.0 is an experimental feature, and not recommended for production use.

 Support Matrix
 ^^^^^^^^^^^^^^

 The support matrix for the Java versions for compiling and running Apache Cassandra 4.0 is detailed in Table 1. The
 build version is along the vertical axis and the run version is along the horizontal axis.

 Table 1 : Support Matrix for Java

 +---------------+--------------+-----------------+
 |               | Java 8 (Run) | Java 11 (Run)   |
 +---------------+--------------+-----------------+
 | Java 8 (Build)|Supported     |Supported        |
 +---------------+--------------+-----------------+
 | Java 11(Build)| Not Supported|Supported        |
 +---------------+--------------+-----------------+

 Essentially Apache 4.0 source code built with Java 11 cannot be run with Java 8. Next, we shall discuss using each of Java 8 and 11 to build and run Apache Cassandra 4.0.

 Using Java 8 to Build
 ^^^^^^^^^^^^^^^^^^^^^

 To start with, install Java 8. As an example, for installing Java 8 on RedHat Linux the command is as follows:

 ::

 $ sudo yum install java-1.8.0-openjdk-devel

 Set ``JAVA_HOME`` and ``JRE_HOME`` environment variables in the shell bash script. First, open the bash script:

 ::

 $ sudo vi ~/.bashrc

 Set the environment variables including the ``PATH``.

 ::

   $ export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk
   $ export JRE_HOME=/usr/lib/jvm/java-1.8.0-openjdk/jre
   $ export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin

 Download and install Apache Cassandra 4.0 source code from the Git along with the dependencies.

 ::

  $ git clone https://github.com/apache/cassandra.git

 If Cassandra is already running stop Cassandra with the following command.

 ::

  [ec2-user@ip-172-30-3-146 bin]$ ./nodetool stopdaemon

 Build the source code from the ``cassandra`` directory, which has the ``build.xml`` build script. The Apache Ant uses the Java version set in the ``JAVA_HOME`` environment variable.

 ::

  $ cd ~/cassandra
  $ ant

 Apache Cassandra 4.0 gets built with Java 8.  Set the environment variable for ``CASSANDRA_HOME`` in the bash script. Also add the ``CASSANDRA_HOME/bin`` to the ``PATH`` variable.

 ::

  $ export CASSANDRA_HOME=~/cassandra
  $ export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin:$CASSANDRA_HOME/bin

 To run Apache Cassandra 4.0 with either of Java 8 or Java 11 run the Cassandra application in the ``CASSANDRA_HOME/bin`` directory, which is in the ``PATH`` env variable.

 ::

  $ cassandra

 The Java version used to run Cassandra gets output as Cassandra is getting started. As an example if Java 11 is used, the run output should include similar to the following output snippet:

 ::

  INFO  [main] 2019-07-31 21:18:16,862 CassandraDaemon.java:480 - Hostname: ip-172-30-3-
  146.ec2.internal:7000:7001
  INFO  [main] 2019-07-31 21:18:16,862 CassandraDaemon.java:487 - JVM vendor/version: OpenJDK
  64-Bit Server VM/11.0.3
  INFO  [main] 2019-07-31 21:18:16,863 CassandraDaemon.java:488 - Heap size:
  1004.000MiB/1004.000MiB

 The following output indicates a single node Cassandra 4.0 cluster has started.

 ::

  INFO  [main] 2019-07-31 21:18:19,687 InboundConnectionInitiator.java:130 - Listening on
  address: (127.0.0.1:7000), nic: lo, encryption: enabled (openssl)
  ...
  ...
  INFO  [main] 2019-07-31 21:18:19,850 StorageService.java:512 - Unable to gossip with any
  peers but continuing anyway since node is in its own seed list
  INFO  [main] 2019-07-31 21:18:19,864 StorageService.java:695 - Loading persisted ring state
  INFO  [main] 2019-07-31 21:18:19,865 StorageService.java:814 - Starting up server gossip
  INFO  [main] 2019-07-31 21:18:20,088 BufferPool.java:216 - Global buffer pool is enabled,
  when pool is exhausted (max is 251.000MiB) it will allocate on heap
  INFO  [main] 2019-07-31 21:18:20,110 StorageService.java:875 - This node will not auto
  bootstrap because it is configured to be a seed node.
  ...
  ...
  INFO  [main] 2019-07-31 21:18:20,809 StorageService.java:1507 - JOINING: Finish joining ring
  INFO  [main] 2019-07-31 21:18:20,921 StorageService.java:2508 - Node 127.0.0.1:7000 state
  jump to NORMAL

 Using Java 11 to Build
 ^^^^^^^^^^^^^^^^^^^^^^
 If Java 11 is used to build Apache Cassandra 4.0, first Java 11 must be installed and the environment variables set. As an example, to download and install Java 11 on RedHat Linux run the following command.

 ::

  $ yum install java-11-openjdk-devel

 Set the environment variables in the bash script for Java 11. The first command is to open the bash script.

 ::

  $ sudo vi ~/.bashrc
  $ export JAVA_HOME=/usr/lib/jvm/java-11-openjdk
  $ export JRE_HOME=/usr/lib/jvm/java-11-openjdk/jre
  $ export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin

 To build source code with Java 11 one of the following two options must be used.

  1. Include Apache Ant command-line option ``-Duse.jdk=11`` as follows:
      ::

       $ ant -Duse.jdk=11

  2. Set environment variable ``CASSANDRA_USE_JDK11`` to ``true``:
      ::

       $ export CASSANDRA_USE_JDK11=true

 As an example, set the environment variable ``CASSANDRA_USE_JDK11`` to ``true``.

 ::

  [ec2-user@ip-172-30-3-146 cassandra]$ export CASSANDRA_USE_JDK11=true
  [ec2-user@ip-172-30-3-146 cassandra]$ ant
  Buildfile: /home/ec2-user/cassandra/build.xml

 Or, set the command-line option.

 ::

  [ec2-user@ip-172-30-3-146 cassandra]$ ant -Duse.jdk11=true

 The build output should include the following.

 ::

  _build_java:
      [echo] Compiling for Java 11
  ...
  ...
  build:

  _main-jar:
           [copy] Copying 1 file to /home/ec2-user/cassandra/build/classes/main/META-INF
       [jar] Building jar: /home/ec2-user/cassandra/build/apache-cassandra-4.0-SNAPSHOT.jar
  ...
  ...
  _build-test:
     [javac] Compiling 739 source files to /home/ec2-user/cassandra/build/test/classes
      [copy] Copying 25 files to /home/ec2-user/cassandra/build/test/classes
  ...
  ...
  jar:
     [mkdir] Created dir: /home/ec2-user/cassandra/build/classes/stress/META-INF
     [mkdir] Created dir: /home/ec2-user/cassandra/build/tools/lib
       [jar] Building jar: /home/ec2-user/cassandra/build/tools/lib/stress.jar
     [mkdir] Created dir: /home/ec2-user/cassandra/build/classes/fqltool/META-INF
       [jar] Building jar: /home/ec2-user/cassandra/build/tools/lib/fqltool.jar

  BUILD SUCCESSFUL
  Total time: 1 minute 3 seconds
  [ec2-user@ip-172-30-3-146 cassandra]$

 Common Issues
 ^^^^^^^^^^^^^^
 One of the two options mentioned must be used to compile with JDK 11 or the build fails and the following error message is output.

 ::

  [ec2-user@ip-172-30-3-146 cassandra]$ ant
  Buildfile: /home/ec2-user/cassandra/build.xml
  validate-build-conf:

  BUILD FAILED
  /home/ec2-user/cassandra/build.xml:293: -Duse.jdk11=true or $CASSANDRA_USE_JDK11=true must
  be set when building from java 11
  Total time: 1 second
  [ec2-user@ip-172-30-3-146 cassandra]$

 The Java 11 built Apache Cassandra 4.0 source code may be run with Java 11 only. If a Java 11 built code is run with Java 8 the following error message gets output.

 ::

  [root@localhost ~]# ssh -i cassandra.pem ec2-user@ec2-3-85-85-75.compute-1.amazonaws.com
  Last login: Wed Jul 31 20:47:26 2019 from 75.155.255.51
  [ec2-user@ip-172-30-3-146 ~]$ echo $JAVA_HOME
  /usr/lib/jvm/java-1.8.0-openjdk
  [ec2-user@ip-172-30-3-146 ~]$ cassandra
  ...
  ...
  Error: A JNI error has occurred, please check your installation and try again
  Exception in thread "main" java.lang.UnsupportedClassVersionError:
  org/apache/cassandra/service/CassandraDaemon has been compiled by a more recent version of
  the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes
  class file versions up to 52.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
    at ...
  ...

 The ``CASSANDRA_USE_JDK11`` variable or the command-line option ``-Duse.jdk11`` cannot be used to build with Java 8. To demonstrate set ``JAVA_HOME`` to version 8.

 ::

  [root@localhost ~]# ssh -i cassandra.pem ec2-user@ec2-3-85-85-75.compute-1.amazonaws.com
  Last login: Wed Jul 31 21:41:50 2019 from 75.155.255.51
  [ec2-user@ip-172-30-3-146 ~]$ echo $JAVA_HOME
  /usr/lib/jvm/java-1.8.0-openjdk

 Set the ``CASSANDRA_USE_JDK11=true`` or command-line option ``-Duse.jdk11=true``. Subsequently, run Apache Ant to start the build. The build fails with error message listed.

 ::

  [ec2-user@ip-172-30-3-146 ~]$ cd
  cassandra
  [ec2-user@ip-172-30-3-146 cassandra]$ export CASSANDRA_USE_JDK11=true
  [ec2-user@ip-172-30-3-146 cassandra]$ ant
  Buildfile: /home/ec2-user/cassandra/build.xml

  validate-build-conf:

  BUILD FAILED
  /home/ec2-user/cassandra/build.xml:285: -Duse.jdk11=true or $CASSANDRA_USE_JDK11=true cannot
  be set when building from java 8

  Total time: 0 seconds
	.. Licensed to the Apache Software Foundation (ASF) under one
	.. or more contributor license agreements. See the NOTICE file
	.. distributed with this work for additional information
	.. regarding copyright ownership. The ASF licenses this file
	.. to you under the Apache License, Version 2.0 (the
	.. "License"); you may not use this file except in compliance
	.. with the License. You may obtain a copy of the License at
	..
	.. http://www.apache.org/licenses/LICENSE-2.0
	..
	.. Unless required by applicable law or agreed to in writing, software
	.. distributed under the License is distributed on an "AS IS" BASIS,
	.. WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	.. See the License for the specific language governing permissions and
	.. limitations under the License.

	Support for Java 11
	-------------------

	In the new Java release cadence a new Java version is made available every six months. The more frequent release cycle
	is favored as it brings new Java features to the developers as and when they are developed without the wait that the
	earlier 3 year release model incurred. Not every Java version is a Long Term Support (LTS) version. After Java 8 the
	next LTS version is Java 11. Java 9, 10, 12 and 13 are all non-LTS versions.

	One of the objectives of the Apache Cassandra 4.0 version is to support the recent LTS Java versions 8 and 11 (`CASSANDRA-9608
	<https://issues.apache.org/jira/browse/CASSANDRA-9608>`_). Java 8 and
	Java 11 may be used to build and run Apache Cassandra 4.0.

	Note: Support for JDK 11 in Apache Cassandra 4.0 is an experimental feature, and not recommended for production use.

	Support Matrix
	^^^^^^^^^^^^^^

	The support matrix for the Java versions for compiling and running Apache Cassandra 4.0 is detailed in Table 1. The
	build version is along the vertical axis and the run version is along the horizontal axis.

	Table 1 : Support Matrix for Java

	+---------------+--------------+-----------------+
	\| \| Java 8 (Run) \| Java 11 (Run) \|
	+---------------+--------------+-----------------+
	\| Java 8 (Build)\|Supported \|Supported \|
	+---------------+--------------+-----------------+
	\| Java 11(Build)\| Not Supported\|Supported \|
	+---------------+--------------+-----------------+

	Essentially Apache 4.0 source code built with Java 11 cannot be run with Java 8. Next, we shall discuss using each of Java 8 and 11 to build and run Apache Cassandra 4.0.

	Using Java 8 to Build
	^^^^^^^^^^^^^^^^^^^^^

	To start with, install Java 8. As an example, for installing Java 8 on RedHat Linux the command is as follows:

	::

	$ sudo yum install java-1.8.0-openjdk-devel

	Set ``JAVA_HOME`` and ``JRE_HOME`` environment variables in the shell bash script. First, open the bash script:

	::

	$ sudo vi ~/.bashrc

	Set the environment variables including the ``PATH``.

	::

	$ export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk
	$ export JRE_HOME=/usr/lib/jvm/java-1.8.0-openjdk/jre
	$ export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin

	Download and install Apache Cassandra 4.0 source code from the Git along with the dependencies.

	::

	$ git clone https://github.com/apache/cassandra.git

	If Cassandra is already running stop Cassandra with the following command.

	::

	[ec2-user@ip-172-30-3-146 bin]$ ./nodetool stopdaemon

	Build the source code from the ``cassandra`` directory, which has the ``build.xml`` build script. The Apache Ant uses the Java version set in the ``JAVA_HOME`` environment variable.

	::

	$ cd ~/cassandra
	$ ant

	Apache Cassandra 4.0 gets built with Java 8. Set the environment variable for ``CASSANDRA_HOME`` in the bash script. Also add the ``CASSANDRA_HOME/bin`` to the ``PATH`` variable.

	::

	$ export CASSANDRA_HOME=~/cassandra
	$ export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin:$CASSANDRA_HOME/bin

	To run Apache Cassandra 4.0 with either of Java 8 or Java 11 run the Cassandra application in the ``CASSANDRA_HOME/bin`` directory, which is in the ``PATH`` env variable.

	::

	$ cassandra

	The Java version used to run Cassandra gets output as Cassandra is getting started. As an example if Java 11 is used, the run output should include similar to the following output snippet:

	::

	INFO [main] 2019-07-31 21:18:16,862 CassandraDaemon.java:480 - Hostname: ip-172-30-3-
	146.ec2.internal:7000:7001
	INFO [main] 2019-07-31 21:18:16,862 CassandraDaemon.java:487 - JVM vendor/version: OpenJDK
	64-Bit Server VM/11.0.3
	INFO [main] 2019-07-31 21:18:16,863 CassandraDaemon.java:488 - Heap size:
	1004.000MiB/1004.000MiB

	The following output indicates a single node Cassandra 4.0 cluster has started.

	::

	INFO [main] 2019-07-31 21:18:19,687 InboundConnectionInitiator.java:130 - Listening on
	address: (127.0.0.1:7000), nic: lo, encryption: enabled (openssl)
	...
	...
	INFO [main] 2019-07-31 21:18:19,850 StorageService.java:512 - Unable to gossip with any
	peers but continuing anyway since node is in its own seed list
	INFO [main] 2019-07-31 21:18:19,864 StorageService.java:695 - Loading persisted ring state
	INFO [main] 2019-07-31 21:18:19,865 StorageService.java:814 - Starting up server gossip
	INFO [main] 2019-07-31 21:18:20,088 BufferPool.java:216 - Global buffer pool is enabled,
	when pool is exhausted (max is 251.000MiB) it will allocate on heap
	INFO [main] 2019-07-31 21:18:20,110 StorageService.java:875 - This node will not auto
	bootstrap because it is configured to be a seed node.
	...
	...
	INFO [main] 2019-07-31 21:18:20,809 StorageService.java:1507 - JOINING: Finish joining ring
	INFO [main] 2019-07-31 21:18:20,921 StorageService.java:2508 - Node 127.0.0.1:7000 state
	jump to NORMAL

	Using Java 11 to Build
	^^^^^^^^^^^^^^^^^^^^^^
	If Java 11 is used to build Apache Cassandra 4.0, first Java 11 must be installed and the environment variables set. As an example, to download and install Java 11 on RedHat Linux run the following command.

	::

	$ yum install java-11-openjdk-devel

	Set the environment variables in the bash script for Java 11. The first command is to open the bash script.

	::

	$ sudo vi ~/.bashrc
	$ export JAVA_HOME=/usr/lib/jvm/java-11-openjdk
	$ export JRE_HOME=/usr/lib/jvm/java-11-openjdk/jre
	$ export PATH=$PATH:$JAVA_HOME/bin:$JRE_HOME/bin

	To build source code with Java 11 one of the following two options must be used.

	1. Include Apache Ant command-line option ``-Duse.jdk=11`` as follows:
	::

	$ ant -Duse.jdk=11

	2. Set environment variable ``CASSANDRA_USE_JDK11`` to ``true``:
	::

	$ export CASSANDRA_USE_JDK11=true

	As an example, set the environment variable ``CASSANDRA_USE_JDK11`` to ``true``.

	::

	[ec2-user@ip-172-30-3-146 cassandra]$ export CASSANDRA_USE_JDK11=true
	[ec2-user@ip-172-30-3-146 cassandra]$ ant
	Buildfile: /home/ec2-user/cassandra/build.xml

	Or, set the command-line option.

	::

	[ec2-user@ip-172-30-3-146 cassandra]$ ant -Duse.jdk11=true

	The build output should include the following.

	::

	_build_java:
	[echo] Compiling for Java 11
	...
	...
	build:

	_main-jar:
	[copy] Copying 1 file to /home/ec2-user/cassandra/build/classes/main/META-INF
	[jar] Building jar: /home/ec2-user/cassandra/build/apache-cassandra-4.0-SNAPSHOT.jar
	...
	...
	_build-test:
	[javac] Compiling 739 source files to /home/ec2-user/cassandra/build/test/classes
	[copy] Copying 25 files to /home/ec2-user/cassandra/build/test/classes
	...
	...
	jar:
	[mkdir] Created dir: /home/ec2-user/cassandra/build/classes/stress/META-INF
	[mkdir] Created dir: /home/ec2-user/cassandra/build/tools/lib
	[jar] Building jar: /home/ec2-user/cassandra/build/tools/lib/stress.jar
	[mkdir] Created dir: /home/ec2-user/cassandra/build/classes/fqltool/META-INF
	[jar] Building jar: /home/ec2-user/cassandra/build/tools/lib/fqltool.jar

	BUILD SUCCESSFUL
	Total time: 1 minute 3 seconds
	[ec2-user@ip-172-30-3-146 cassandra]$

	Common Issues
	^^^^^^^^^^^^^^
	One of the two options mentioned must be used to compile with JDK 11 or the build fails and the following error message is output.

	::

	[ec2-user@ip-172-30-3-146 cassandra]$ ant
	Buildfile: /home/ec2-user/cassandra/build.xml
	validate-build-conf:

	BUILD FAILED
	/home/ec2-user/cassandra/build.xml:293: -Duse.jdk11=true or $CASSANDRA_USE_JDK11=true must
	be set when building from java 11
	Total time: 1 second
	[ec2-user@ip-172-30-3-146 cassandra]$

	The Java 11 built Apache Cassandra 4.0 source code may be run with Java 11 only. If a Java 11 built code is run with Java 8 the following error message gets output.

	::

	[root@localhost ~]# ssh -i cassandra.pem ec2-user@ec2-3-85-85-75.compute-1.amazonaws.com
	Last login: Wed Jul 31 20:47:26 2019 from 75.155.255.51
	[ec2-user@ip-172-30-3-146 ~]$ echo $JAVA_HOME
	/usr/lib/jvm/java-1.8.0-openjdk
	[ec2-user@ip-172-30-3-146 ~]$ cassandra
	...
	...
	Error: A JNI error has occurred, please check your installation and try again
	Exception in thread "main" java.lang.UnsupportedClassVersionError:
	org/apache/cassandra/service/CassandraDaemon has been compiled by a more recent version of
	the Java Runtime (class file version 55.0), this version of the Java Runtime only recognizes
	class file versions up to 52.0
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:763)
	at ...
	...

	The ``CASSANDRA_USE_JDK11`` variable or the command-line option ``-Duse.jdk11`` cannot be used to build with Java 8. To demonstrate set ``JAVA_HOME`` to version 8.

	::

	[root@localhost ~]# ssh -i cassandra.pem ec2-user@ec2-3-85-85-75.compute-1.amazonaws.com
	Last login: Wed Jul 31 21:41:50 2019 from 75.155.255.51
	[ec2-user@ip-172-30-3-146 ~]$ echo $JAVA_HOME
	/usr/lib/jvm/java-1.8.0-openjdk

	Set the ``CASSANDRA_USE_JDK11=true`` or command-line option ``-Duse.jdk11=true``. Subsequently, run Apache Ant to start the build. The build fails with error message listed.

	::

	[ec2-user@ip-172-30-3-146 ~]$ cd
	cassandra
	[ec2-user@ip-172-30-3-146 cassandra]$ export CASSANDRA_USE_JDK11=true
	[ec2-user@ip-172-30-3-146 cassandra]$ ant
	Buildfile: /home/ec2-user/cassandra/build.xml

	validate-build-conf:

	BUILD FAILED
	/home/ec2-user/cassandra/build.xml:285: -Duse.jdk11=true or $CASSANDRA_USE_JDK11=true cannot
	be set when building from java 8

	Total time: 0 seconds