Home | Forums | Couchbase | Couchbase Server 2.0

Does CB 2.0 support auto-rebalance after failover

5 replies [Last post]
Wed, 01/02/2013 - 21:48
kaprikorn07
Offline
Joined: 12/07/2012
Groups: None

Hi everyone,

In a RHEL cluster CB 2.0 setup, is there any option of "automatic rebalance" for these scenarios:
1. After a node fails i.e., failover
2. After addition/deletion of a node.

Please help!

Cheers,
Bharath

Top
Thu, 01/03/2013 - 11:26
tgrall
Offline
Joined: 09/05/2012
Groups: None

Hello,

Yes it is supported, but not activated by default.

The easiest way to activate it:

  1. Go to the "Web Admin Console"
  2. Click on "Settings" tab
  3. Then select "Auto Failover" and enable it

Regards
Tug
@tgrall

__________________

Tug
@tgrall

Top
Thu, 01/03/2013 - 21:43
kaprikorn07
Offline
Joined: 12/07/2012
Groups: None

Hi Tug,

Thanks for the reply. But I was asking for "auto-rebalance" not auto-failover.
Please let me know.

Best Regards,
Bharath

Top
Fri, 01/04/2013 - 00:00
tgrall
Offline
Joined: 09/05/2012
Groups: None

Hi,

Sorry I misread your question.

Today it is not possible to have auto-rebalance, one of the reason is because in some deployment sysadmins are adding more than one node and then want to chose when they are doing the rebalance. (when everything is ready, avoiding peak of activity, ...)

Could you let me know why you need this feature?

Note that if you want to automate some task you can always use the command line interface CLI, to add new node to the cluster and then do the rebalance. Take a look to this page:
- http://www.couchbase.com/docs/couchbase-manual-2.0/couchbase-admin-cmdli...

Regards
Tug

__________________

Tug
@tgrall

Top
Fri, 01/04/2013 - 08:23
Neo-matrix
Offline
Joined: 10/15/2012
Groups: None

Hi,
Just to add a point to Tug's reply, if there is a node failure, then doing the rebalance makes the cluster(undersized cluster) handle more load, which might lead to undesired collapse in some cases. Hence, the sysadmins are careful in making it as a swap rebalance to keep the couchbase up and running fine.

Thanks,
Neo.

Top
Mon, 01/07/2013 - 21:58
kaprikorn07
Offline
Joined: 12/07/2012
Groups: None

Hi Neo/Tug,

Thanks a lot for your thorough replies. My case is like I need to automate the re-balance after one or more nodes are added or deleted. I have these doubts:
1. How to trigger my script based on the addition/deletion of nodes?
2. Or should I have something like cron to check for prescribed time intervals?

So could you guys please let me know how to actually do this?

Thanks & regards,
Bharath

Top