Re: Ubuntu 12.04 - Which JDK? and some more

["ac@hsk.hk" <ac...@hsk.hk>]

Hi,

After spending time to research Hadoop and Hbase JDK requirements, here is my advice about using Ubuntu 12.04: 
 
1) If you plan to use HBase on Hadoop HDFS, do note that HBase will run on Oracle's JDK only, so do NOT use OpenJDK or other JDKs for the setup. 
2) When installing Ubuntu, should NOT use LVM (Linux Logical Volume Manager) for Hadoop data disks! (There will be performance issue between the filesystem and the device, LVM is the default for some Linux package, be careful not to select LVM)

regards

On 8 Nov 2012, at 6:12 PM, ac@hsk.hk wrote:

> Hi, thank you for your info and will head for it. Thanks.
> On 8 Nov 2012, at 6:07 PM, Mohammad Tariq wrote:
> 
>> Hi there,
>> 
>>     As per my understanding, all the code has been built and tested against java6(sun). There are some changes between java7 and 6 and you may face issues while running your code, like using sort with collections. I faced the same thing when using List.sort in my code. So, it's better to go with sun's java6. If you want to install it you can follow these steps :
>> 
>> 1. Download the zipped file and extract it.
>> 
>> 2. chmod +x jdk-6u37-linux-x64.bin
>> 
>> 3. ./jdk-6u37-linux-x64.bin
>> 
>> 4. sudo mv jdk1.6.0_37/ /usr/lib/jvm/
>> 
>> 5. sudo update-alternatives --install /usr/bin/javac javac /usr/lib/jvm/jdk1.6.0_37/bin/javac 1
>> 
>> 6. sudo update-alternatives --install /usr/bin/java java /usr/lib/jvm/jdk1.6.0_37/bin/java 1
>> 
>> 7. sudo update-alternatives --install /usr/bin/javaws javaws /usr/lib/jvm/jdk1.6.0_37/bin/javaws 1
>> 
>> Then choose which java to use :
>> 
>> sudo update-alternatives --config java
>> 
>> choose the no for java6
>> 
>> Regards,
>>     Mohammad Tariq
>> 
>> 
>> 
>> On Thu, Nov 8, 2012 at 2:29 PM, ac@hsk.hk <ac...@hsk.hk> wrote:
>> Thanks Harsh,
>> 
>> This is exactly what I am facing, I have used Ubuntu for long time, 12.04 is the Long Term Support version (LTS),  however Oracle JDK/JRE6  is no longer supported in it,  "OpenJDK has sometimes a odd behavior - Alexander Lorenz'".  Any Ubuntu 12.04 users here to share your selections/options?
>> 
>> Thanks
>> 
>> 
>> On 8 Nov 2012, at 4:37 PM, Harsh J wrote:
>> 
>> > Hi Sanjeev,
>> >
>> > Unfortunately, official Ubuntu repositories no longer supports Oracle
>> > JDK/JRE 6. See https://help.ubuntu.com/community/Java#Oracle_.28Sun.29_Java_6
>> >
>> > On Thu, Nov 8, 2012 at 11:47 AM, Sanjeev Verma
>> > <sa...@gmail.com> wrote:
>> >> AFAIK, openjdk can be used to run hadoop. Why do you want to build hadoop
>> >> from source? Get precompiled binaries and you will be ok.
>> >>
>> >> Also, you can install sun/oracle jdk on ubuntu. Just google for
>> >> instructions, u will find plenty, like here -
>> >> http://www.ubuntututorials.com/install-oracle-java-jdk-7-ubuntu-12-04/.
>> >> These are for jdk 7, but you can follow the same to install jdk 6.
>> >>
>> >> Enjoy!
>> >>
>> >> On Nov 8, 2012 11:30 AM, "ac@hsk.hk" <ac...@hsk.hk> wrote:
>> >>>
>> >>> Hi,
>> >>>
>> >>> I am planning to use Ubuntu 12.04, from
>> >>> http://wiki.apache.org/hadoop/HadoopJavaVersions, about OpenJDK
>> >>>
>> >>> "Note*: OpenJDK6 has some open bugs w.r.t handling of generics... so
>> >>> OpenJDK cannot be used to compile hadoop mapreduce code in branch-0.23 and
>> >>> beyond, please use other JDKs."
>> >>>
>> >>> Is it OK to use OpenJDK 7 in Ubuntu 12.04?
>> >>>
>> >>> Thanks
>> >>>
>> >>
>> >
>> >
>> >
>> > --
>> > Harsh J
>> 
>> 
>