Part 4 prepare the Java Runtime Environment for cassandra1.0.x

Note: This article is a test in the itanium64-bit redhatas5 environment. In fact, it is equally feasible for other RedHat-compatible systems, such as centos, the translator successfully completed the task at 32 for centos6.

Installing Sun JRE on Redhat Systems

Install sunjre on the RedHat System

 

Original

Datastax recommends installing the mostrecently released version of the Oracle Sun Java Runtime Environment (JRE), also referred to as the Java Virtual Machine (JVM). Versions earlier than1.6.0 _ 19 shocould not be used.

 

Translation

Datastax recommends that you install the latest version of Oracle Sun JRE, or a Java Virtual Machine. Versions earlier than 1.6.0 _ 19 cannot be used and must be 1.6.0 _ 19 or later JRE versions to run cassandra1.0.x normally.

 

Original

The RPM packages install the openjdk javaruntime Environment (JRE) instead of the Oracle Sun JRE. After installing usingthe RPM packaged releases, configure your operating system to use the oraclesun JRE instead of openjdk.

 

Translation

Openjdk is installed by default during the initial installation of the operating system. Therefore, we must install the JDK of Oracle sun and replace the original openjdk.

 

Original

Check which version of the Java runtimeenvironment your system is using. If your system is using the openjdk runtimeenvironment, you will need to change it to use the Oracle Sun JRE.

$ Java-version

 

Translation

Confirm the version of the JRE you want to run. If your system uses openjdk, you must reinstall the JDK of Oracle sun to replace it.

$ Java-version

(Translator's note: Check whether the version meets the requirements. If yes, skip the JRE installation step)

 

Original

Go to
Oracle javaruntime environment download page, accept the license agreement, anddownload the Linux x64-RPM installer or Linuxx86-RPM Installer (depending on yourplatform ).

 

Translation

Go to the Oracle Java Runtime Environment Download Page

Http://www.oracle.com/technetwork/java/javase/downloads/jre-6u25-download-346243.html)

Download Sun JDK and select an appropriate version. Download the appropriate RPM package based on your machine's CPU chip and hardware options, such as a 32 system, the 64 files you downloaded cannot be installed.

 

Original

Go to the directory where you downloadedthe JRE package, and change the permissions so the file is executable. Forexample:

$ CD/tmp

$ Chmod A + x jre-6u25-linux-x64-rpm.bin

 

Translation

Go to the JRE directory you downloaded and change the directory permissions so that they can be authorized to other users.

$ CD/tmp

$ Chmod A + x jre-6u25-linux-x64-rpm.bin

 

Original

Extract and run the RPM file. For example:

$ Sudo./jre-6u25-linux-x64-rpm.bin

The RPM INSTALLThe JRE into/usr/Java /.

 

Translation

Decompress and run rpm, for example:

$ Sudo./jre-6u25-linux-x64-rpm.bin

The RPM package installs the Java Runtime Environment to the/usr/Java/directory of the system.

 

Original

Configure your system so that it is usingthe Oracle Sun JRE instead of the openjdk JRE. Use the alternatives command toadd a symbolic link to the Oracle Sun JRE installation. For example:

$ Sudo alternatives -- install/usr/bin/Java/usr/Java/jre1.6.0 _ 25/bin/Java 20000

 

Translation

Configure the system's default JRE, replace openjdk with javaslrsunjre, and use the alternatives command to configure the system's JDK to transfer the runtime environment with oraclesun JRE. For example:

$ Sudo alternatives -- install/usr/bin/Java/usr/Java/jre1.6.0 _ 25/bin/Java 20000

 

Original

Make sure your system is now using thecorrect JRE. For example:

$ Java-version

 

Translation

Confirm your JRE version again

$ Java-version

 

Original

If the openjdk JRE is still being used, usethe alternatives command to switch it. For example:

$ Sudo alternatives -- config Java

There are 2 programs which provide 'java '.

 

Selection command

-----------------------------------------------

/Usr/lib/JVM/jre-1.6.0-openjdk.x86_64/bin/Java

* + 2/usr/Java/jre1.6.0 _ 25/bin/Java

 

Enter to keep the current selection [+], or typeselection number: 2

 

Translation

If openjdk is still in use, you can use the alternatives command to switch, for example:

$ Sudo alternatives -- config Java

There are 2 programs which provide 'java '.

 

Selection command

-----------------------------------------------

/Usr/lib/JVM/jre-1.6.0-openjdk.x86_64/bin/Java

* + 2/usr/Java/jre1.6.0 _ 25/bin/Java

 

Enter to keep the current selection [+], or typeselection number: 2

Note: At this time, we should switch to Oracle Sun's JRE.