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Posted to user@cassandra.apache.org by Tharindu Mathew <mc...@gmail.com> on 2012/03/06 13:43:47 UTC

Repairing nodes when two schema versions appear

Hi,

I try to add column families programatically and end up with 2 schema
versions in the Cassandra cluster. Using Cassandra 0.7.

Is there a way to bring this back to normal (to one schema version) through
the cli or through the API?

-- 
Regards,

Tharindu

blog: http://mackiemathew.com/

Re: Repairing nodes when two schema versions appear

Posted by aaron morton <aa...@thelastpickle.com>.
> 1. Can this schema version issue happen in newer versions of Cassandra (>1.0) ?
AFAIK yes. Schema changes are assumed to happen infrequently, and to only be started if the cluster is in schema agreement. Clients (include the CLI and CQL) take care of this. 

> 2. When the node is UP and we do this, even though logs errors, still would everything come back to normal just like we shut down and delete and restart?
You need to shut it down to delete the files, then start. Assuming RF >=3 and QUOURM CL, if the restarting node fails to read or write data requests will still succeed. 

Cheers

-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com

On 7/03/2012, at 9:12 PM, Tharindu Mathew wrote:

> Thanks Aaron. 
> 
> This is great. A couple of questions if you don't mind...
> 
> 1. Can this schema version issue happen in newer versions of Cassandra (>1.0) ?
> 
> 2. When the node is UP and we do this, even though logs errors, still would everything come back to normal just like we shut down and delete and restart?
> 
> On Wed, Mar 7, 2012 at 2:07 AM, aaron morton <aa...@thelastpickle.com> wrote:
> Go to one of the nodes, stop it and delete the Migrations and Schema files in the system keyspace. 
> 
> When you restart the node it will stream the migrations the other. Note that if the node is UP and accepting traffic it may log errors about missing CF's during this time. 
> 
> Cheers 
> 
> 
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
> 
> On 7/03/2012, at 1:43 AM, Tharindu Mathew wrote:
> 
>> Hi,
>> 
>> I try to add column families programatically and end up with 2 schema versions in the Cassandra cluster. Using Cassandra 0.7.
>> 
>> Is there a way to bring this back to normal (to one schema version) through the cli or through the API?
>> 
>> -- 
>> Regards,
>> 
>> Tharindu
>> 
>> blog: http://mackiemathew.com/
>> 
> 
> 
> 
> 
> -- 
> Regards,
> 
> Tharindu
> 
> blog: http://mackiemathew.com/
> 


Re: Repairing nodes when two schema versions appear

Posted by Tharindu Mathew <mc...@gmail.com>.
Thanks Aaron.

This is great. A couple of questions if you don't mind...

1. Can this schema version issue happen in newer versions of Cassandra
(>1.0) ?

2. When the node is UP and we do this, even though logs errors, still would
everything come back to normal just like we shut down and delete and
restart?

On Wed, Mar 7, 2012 at 2:07 AM, aaron morton <aa...@thelastpickle.com>wrote:

> Go to one of the nodes, stop it and delete the Migrations and Schema files
> in the system keyspace.
>
> When you restart the node it will stream the migrations the other. Note
> that if the node is UP and accepting traffic it may log errors about
> missing CF's during this time.
>
> Cheers
>
>
> -----------------
> Aaron Morton
> Freelance Developer
> @aaronmorton
> http://www.thelastpickle.com
>
> On 7/03/2012, at 1:43 AM, Tharindu Mathew wrote:
>
> Hi,
>
> I try to add column families programatically and end up with 2 schema
> versions in the Cassandra cluster. Using Cassandra 0.7.
>
> Is there a way to bring this back to normal (to one schema version)
> through the cli or through the API?
>
> --
> Regards,
>
> Tharindu
>
> blog: http://mackiemathew.com/
>
>
>


-- 
Regards,

Tharindu

blog: http://mackiemathew.com/

Re: Repairing nodes when two schema versions appear

Posted by aaron morton <aa...@thelastpickle.com>.
Go to one of the nodes, stop it and delete the Migrations and Schema files in the system keyspace. 

When you restart the node it will stream the migrations the other. Note that if the node is UP and accepting traffic it may log errors about missing CF's during this time. 

Cheers 


-----------------
Aaron Morton
Freelance Developer
@aaronmorton
http://www.thelastpickle.com

On 7/03/2012, at 1:43 AM, Tharindu Mathew wrote:

> Hi,
> 
> I try to add column families programatically and end up with 2 schema versions in the Cassandra cluster. Using Cassandra 0.7.
> 
> Is there a way to bring this back to normal (to one schema version) through the cli or through the API?
> 
> -- 
> Regards,
> 
> Tharindu
> 
> blog: http://mackiemathew.com/
>