Nilesh_Sangani@... 2013-01-24, 17:28
Moving the post to [EMAIL PROTECTED]
as it is CDH4 you specifically are asking about. BCC'd user@hadoop
lists, lets carry forward the discussion on the CDH lists. My response
RHEL 5.x and 6.x wil be supported. Means, RHEL 6.3 too.
On Jan 24, 2013, at 6:28 PM, <[EMAIL PROTECTED]> wrote:
> We are working on implementing Cloudera distributed Hadoop (CDH 4.x) on our environment. Cloudera website talks about supporting RHEL 6.1 version with challenges/issues with the newer version. It also though provides a workaround for it. Wanted to hear from the community on the supported versions of RedHat Linux and any guidance on which version to choose?
> Red Hat Linux (RHEL 6.2 and 6.3)
> - Poor performance running Hadoop on RHEL 6.2 or later when transparent hugepage compaction is enabled
> RHEL 6.2 and 6.3 include a feature called "transparent hugepage compaction" which interacts poorly with Hadoop workloads. This can cause a serious performance regression compared to other operating system versions on the same hardware.
> Symptom: top and other system monitoring tools show a large percentage of the CPU usage classified as "system CPU". If system CPU usage is 30% or more of the total CPU usage, your system may be experiencing this issue.
> Bug: https://bugzilla.redhat.com/show_bug.cgi?id=805593
> Severity: Medium (up to 3x performance loss)
> Anticipated Resolution: Currently working with Red Hat to resolve for a future RHEL update
> Workaround: Add the following command to /etc/rc.local to disable transparent hugepage compaction:
> echo never > /sys/kernel/mm/redhat_transparent_hugepage/defrag
German Hadoop LinkedIn Group: http://goo.gl/N8pCF