Support Questions
Find answers, ask questions, and share your expertise
Announcements
Alert: Welcome to the Unified Cloudera Community. Former HCC members be sure to read and learn how to activate your account here.

How to do an OS upgrade on 15 nodes cloudera cluster from centos 6 to centos 7

How to do an OS upgrade on 15 nodes cloudera cluster from centos 6 to centos 7

New Contributor

Hello,

 

Is there documention to perform an OS upgrade form CentOS 6  to CentOS 7 on a multi nodes cluster?

I was thinking to:

 

1) Update to lastest CDH version on all my nodes

2) Retired a datanode of my cluster ( since i want to rename the server also )

3) do the OS fresh install ( since we go from centOS 6 to CentOS 7  )

4) Add the node back to the cluster  - at this point i will have a cluster with mixed OS nodes. for couples of days ....

5) Is there specific instruction for the namenode ?

 

 

 

 

7 REPLIES 7

Re: How to do an OS upgrade on 15 nodes cloudera cluster from centos 6 to centos 7

Super Collaborator

Please review the following documentation [1] that discuss the limitation of this upgrade.

 

[1] http://www.cloudera.com/documentation/enterprise/latest/topics/cm_ig_cm_requirements.html

Re: How to do an OS upgrade on 15 nodes cloudera cluster from centos 6 to centos 7

New Contributor
Hello

The only pertinent to my question i see is 'Using the same version of the
same operating system on all cluster hosts is strongly recommended.'

This not give me a lot of help in my upgrade process.....

Yves

Re: How to do an OS upgrade on 15 nodes cloudera cluster from centos 6 to centos 7

Super Collaborator

Is this managed by Cloudera Manager if so is ti parcel or packages based install?

Re: How to do an OS upgrade on 15 nodes cloudera cluster from centos 6 to centos 7

New Contributor
Manage with cloudera manager with parcels

Re: How to do an OS upgrade on 15 nodes cloudera cluster from centos 6 to centos 7

New Contributor

Any pointer for doing this will be greatly appreciated ....

Re: How to do an OS upgrade on 15 nodes cloudera cluster from centos 6 to centos 7

Super Collaborator

As long as the parcels are deployed+activated, mount/directories for CM (/var/run/cloudera-scm-*) and CDH services (ie: HDFS/dfs.data.dir, dfs.datanode.data.dir,dfs.name.dir; Zookeeper/var/lib/zookeeper; etc) remain unchanged on your host, and are available when you bring up the cluster, there's shouldn't be any issues.

 

> 5) Is there specific instruction for the namenode ? see [1] or [2]

Back up HDFS Metadata
If upgrading from:
  • CDH 5.0 or 5.1 to 5.2 or higher
  • CDH 5.2 or 5.3 to 5.4 or higher

Back up HDFS metadata using the following command:

hdfs dfsadmin -fetchImage local directory

  

Let me know if this helps,

 

Michalis

 

[1] http://cloudera.com/documentation/enterprise/latest/topics/install_rolling_upgrade_to_cdh55.html#con...

[2] Step 1. "4. Back up the HDFS metadata on the NameNode machine, as follows."

http://cloudera.com/documentation/enterprise/latest/topics/cdh_ig_upgrade_to_latest.html#topic_8_2_1...

 

 

 

Re: How to do an OS upgrade on 15 nodes cloudera cluster from centos 6 to centos 7

Explorer

If you have not done already.

 

I followed the below approach.

 

1. I did the OS upgrade one by one

2. First move all the services(data node,node manager,etc...) from that node to other nodes. Delete that host from CDH cluster.

3. Upgrade the OS from centos 6 to centos 7

4. Now install the cloudera manager agent in centos 7 which will connect to cloudera manager server running in centos 6.

5. Here the problem comes. Cloudera manager server will not be able to distribute the CDH parcles to the new centos 7 server because of the os version mismatch. I already have the CDH distribution for centos 7 in my staging environment. I copy those in to production (centos 7)  under /opt/cloudera/parcels. So now CDH distribution is available in centos 7 server. I just restarted the cloudera agent in centos 7 and it was ready to join the CDH cluster.