Migration from CDH3

[#1]

Good afternoon everyone,

We are using hbase for 3 years now, and we have the version 0.90.3 because we have never migrate since this time.

We use an application which is using hbase, we didn't do anything by ourselves in hbase but we need it to improve the perf of the application we use.

Now, we think it could be a good idea to migrate to the latest version (maybe a little bit late :/).

What is the best process according to you ?

==> Install the new hbase (CDH 5.4.5), migrate the datas from my previous install to the new one (can I use tools like DistCp  ?) and it's good ?

==> Do I have to reuse my HDFS ?

==> Is there any documentation about how to migrate properly ? Do I have to download temp version between mine and the new one ?

I have an hadoop/hbase install done in cluster on 2 servers, but I hadn't do it and don't know a lot of it.

Thanks a lot for any advise !

[#2]

> Now, we think it could be a good idea to migrate to the latest version (maybe a little bit late :/).

Better late than never!

> ==> Install the new hbase (CDH 5.4.5), migrate the datas from my previous install to the new one (can I use tools like DistCp ?) and it's good ?

Unfortunately, with HBase, you do have to do a double-step upgrade (CDH3 (EOM) -> CDH4 (EOM) -> CDH5 (Supported)) since the current codebase has no more support for HFileV1 format files that C3 used.

> ==> Do I have to reuse my HDFS ?

You will be upgrading the whole of CDH, incl. HDFS within it. The newer HBase libs require newer offered HDFS features/improvements.

> ==> Is there any documentation about how to migrate properly ? Do I have to download temp version between mine and the new one ?

Yes, you can find upgrade instructions for C3 -> C4 at http://www.cloudera.com/content/cloudera/en/documentation/cdh4/latest/CDH4-Installation-Guide/cdh4ig... and for C4 -> C5 at http://www.cloudera.com/content/cloudera/en/documentation/core/latest/topics/cdh_ig_upgrade_command_...

[#3]

Thanks a lot for your answer ! I have asked for a temp server to do some tests !