Re: hbase replication for higher availability

[Enis Söztutar <en...@apache.org>]

Hey,

Indeed it is a viable approach. Some of the HBase deployments use the
master-master replication model across DCs. The consistency semantics will
obvious depend on the application use case.

However, there is no out-of-the-box client to do across-DC requests. But
wrapping the HBase client in a higher level should give you the
possibility.

On the other hand, we are adding high available reads within the DC in the
issue HBASE-10070. You can track the development there.

Cheers,
Enis


On Mon, Mar 31, 2014 at 3:37 PM, Jeff Storey <st...@gmail.com> wrote:

> Thank you for the input.
>
>
> On Sun, Mar 30, 2014 at 8:10 PM, Vladimir Rodionov
> <vr...@carrieriq.com>wrote:
>
> > It can be viable approach if you can keep replication lag under control.
> >
> > > I'm not sure how the java api deals with reading from a region server
> > that
> > > is in the process of failing over? Is there a way to detect that?
> >
> > Do two reads in sequence:
> >
> > 1. Read primary cluster
> > 2. Read secondary if 1. exceeds your time - out .
> >
> > Best regards,
> > Vladimir Rodionov
> > Principal Platform Engineer
> > Carrier IQ, www.carrieriq.com
> > e-mail: vrodionov@carrieriq.com
> >
> > ________________________________________
> > From: Jeff Storey [storey.jeff@gmail.com]
> > Sent: Sunday, March 30, 2014 2:31 PM
> > To: user@hbase.apache.org
> > Subject: hbase replication for higher availability
> >
> > In evaluating strategies for minimizing downtime when a region server
> > fails, in addition to the common approaches such as lowering the
> zookeeper
> > timeout, is it possible to use replication to improve availability (at
> the
> > cost of consistency) for reads?
> >
> > I'm still getting more familiar with the HBASE api, but my thought would
> be
> > to do something like:
> >
> > - attempt read from the primary cluster
> > - if read fails because of downed region server, read from slave cluster
> > (understanding that the read may be a little bit stale)
> >
> > I wouldn't expect this to happen too frequently, but in a case where I
> > would rather return slightly stale data rather than no data, is this a
> > viable approach?
> >
> > I'm not sure how the java api deals with reading from a region server
> that
> > is in the process of failing over? Is there a way to detect that?
> >
> > Thanks for the help.
> >
> > Confidentiality Notice:  The information contained in this message,
> > including any attachments hereto, may be confidential and is intended to
> be
> > read only by the individual or entity to whom this message is addressed.
> If
> > the reader of this message is not the intended recipient or an agent or
> > designee of the intended recipient, please note that any review, use,
> > disclosure or distribution of this message or its attachments, in any
> form,
> > is strictly prohibited.  If you have received this message in error,
> please
> > immediately notify the sender and/or Notifications@carrieriq.com and
> > delete or destroy any copy of this message and its attachments.
> >
>