Mark,

This is the parent issue of the HA NameNode work: 
https://issues.apache.org/jira/browse/HDFS-1623

On 30-Oct-2011, at 2:07 AM, Mark wrote:

> I was unaware of Avatarnode and the future plans to integrate such a 
> solution. This makes feel a lot more at ease in choosing HBase.
> 
> Do you happen to have a JIRA ticket that references this ticket so I can 
> monitor it and if possible, contribute.
> 
> Thanks
> 
> On 10/29/11 1:34 PM, lars hofhansl wrote:
>> This is more of "theoretical problem" really.
>> Yahoo and others claim they lost far more data due to human error than any 
>> HDFS problems (including Namenode failures).
>> 
>> You can prevent data loss by having the namenode write the metadata to 
>> another machine (via NFS or DRBD or if you have a SAN).
>> You'll still have an outage while switching over to a different machine, but 
>> at least you won't lose any data.
>> 
>> 
>> Facebook has a partial solution (Avatarnode) and the HSFS folks are working 
>> on a solution (which like Avatarnode mainly involves keeping
>> a hot copy of the Namenode so that failover is "instantaneous" - 1 or 2 
>> minutes at most).
>> 
>> 
>> ----- Original Message -----
>> From: Mark<[email protected]>
>> To: [email protected]
>> Cc:
>> Sent: Saturday, October 29, 2011 11:46 AM
>> Subject: Dealing with single point of failure
>> 
>> How does one deal with the fact that HBase has a single point of failure.. 
>> namely the namenode. What steps can be taken to eliminate and/or minimize 
>> the impact of a namenode failure? What can a situation where reliability is 
>> of utmost importance should one choose an alternative technology.. ie 
>> Cassandra?
>> 
>> Thanks
>> 

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