hbase-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Anoop John <anoop.hb...@gmail.com>
Subject Re: On HBase Read Replicas
Date Thu, 16 Feb 2017 17:41:20 GMT
Never saw this kind of discussion.

-Anoop-

On Thu, Feb 16, 2017 at 10:13 PM, jeff saremi <jeffsaremi@hotmail.com> wrote:
> Thanks Anoop.
>
> Understood.
>
> Have there been enhancement requests or discussions on load balancing by providing additional
replicas in the past? Has anyone else come up with anything on this?
> thanks
>
> ________________________________
> From: Anoop John <anoop.hbase@gmail.com>
> Sent: Thursday, February 16, 2017 2:35:48 AM
> To: user@hbase.apache.org
> Subject: Re: On HBase Read Replicas
>
> The region replica feature came in so as to reduce the MTTR and so
> increase the data availability.  When the master region containing RS
> dies, the clients can read from the secondary regions.  But to keep
> one thing in mind that this data from secondary regions will be bit
> out of sync as the replica is eventual consistent.   Because of this
> said reason,  change client so as to share the load across diff RSs
> might be tough.
>
> -Anoop-
>
> On Sun, Feb 12, 2017 at 8:13 AM, jeff saremi <jeffsaremi@hotmail.com> wrote:
>> Yes indeed. thank you very much Ted
>>
>> ________________________________
>> From: Ted Yu <yuzhihong@gmail.com>
>> Sent: Saturday, February 11, 2017 3:40:50 PM
>> To: user@hbase.apache.org
>> Subject: Re: On HBase Read Replicas
>>
>> Please take a look at the design doc attached to
>> https://issues.apache.org/jira/browse/HBASE-10070.
>>
>> Your first question would be answered by that document.
>>
>> Cheers
>>
>> On Sat, Feb 11, 2017 at 2:06 PM, jeff saremi <jeffsaremi@hotmail.com> wrote:
>>
>>> The first time I heard replicas in HBase the following thought immediately
>>> came to my mind:
>>> To alleviate the load in read-heavy clusters, one could assign Region
>>> servers to be replicas of others so that the load is distributed and there
>>> is less pressure on the main RS.
>>>
>>> Just 2 days ago a colleague quoted a paragraph from HBase manual that
>>> contradicted this completely. Apparently, the replicas do not help with the
>>> load but they actually contribute to more traffic on the network and on the
>>> underlying file system
>>>
>>> Would someone be able to give us some insight on why anyone would want
>>> replicas?
>>>
>>> And also could one easily change this behavior in the HBase native Java
>>> client to support what I had been imagining as the concept for replicas?
>>>
>>>
>>> thanks
>>>

Mime
View raw message