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Posted to user@hbase.apache.org by "shanmuganathan.r" <sh...@zohocorp.com> on 2011/07/18 16:24:20 UTC
Basic information about HBase?
Hi,
I am the new user for the HBase .I installed Hadoop 0.20.2, Zookeeper 3.3.3, HBase 0.90.1 in three node cluster. They are working properly.
I have some doubts on it.
1. What will happen if the HMaster is crashed and How can we recover the data during that time?
2. Are we need to start the zookeeper servers separately ?
Re: Basic information about HBase?
Posted by Stack <st...@duboce.net>.
I would second what Doug says. The below are basic questions answered
over in the site book he cites.
St.Ack
On Mon, Jul 18, 2011 at 7:24 AM, shanmuganathan.r
<sh...@zohocorp.com> wrote:
>
>
>
>
> Hi,
>
> I am the new user for the HBase .I installed Hadoop 0.20.2, Zookeeper 3.3.3, HBase 0.90.1 in three node cluster. They are working properly.
> I have some doubts on it.
>
>
> 1. What will happen if the HMaster is crashed and How can we recover the data during that time?
>
>
> 2. Are we need to start the zookeeper servers separately ?
>
>
>
>
>
Re: Basic information about HBase?
Posted by Harsh J <ha...@cloudera.com>.
Hello,
Inline:
On 18-Jul-2011, at 7:54 PM, shanmuganathan.r wrote:
>
>
> 1. What will happen if the HMaster is crashed and How can we recover the data during that time?
You can run a backup hmaster, and that can take over when the primary falls. Otherwise, the HMaster stores its data on the HDFS and the ZooKeeper data directories, and can recover if you restart it. You shouldn't need to perform any form of local data recovery to bring HMaster back up afaik.
>
>
> 2. Are we need to start the zookeeper servers separately ?
Its best if you manage it separately. For 3 nodes, a single ZK instance is sufficient, so ensure you do backup that data directory of its from time to time.
Re: Basic information about HBase?
Posted by Doug Meil <do...@explorysmedical.com>.
Hi there-
Read this for starters...
http://hbase.apache.org/book.html
On 7/18/11 10:24 AM, "shanmuganathan.r" <sh...@zohocorp.com>
wrote:
>
>
>
>
>Hi,
>
> I am the new user for the HBase .I installed Hadoop 0.20.2,
>Zookeeper 3.3.3, HBase 0.90.1 in three node cluster. They are working
>properly.
> I have some doubts on it.
>
>
>1. What will happen if the HMaster is crashed and How can we recover the
>data during that time?
>
>
>2. Are we need to start the zookeeper servers separately ?
>
>
>
>