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Posted to user@cassandra.apache.org by David Boxenhorn <da...@lookin2.com> on 2010/08/04 10:27:08 UTC
Changing schema w/o losing data - Can it be done?
When I change schema I need to delete the commit logs - otherwise I get a
null pointer exception.
Is there a way that I can force Cassandra to empty the commit logs so I
won't lose data???
(There has not been much recent activity, nor is there much current
activity. There was only one log and it was only 54K.)
Re: Changing schema w/o losing data - Can it be done?
Posted by Gary Dusbabek <gd...@gmail.com>.
NullPointerException--it sounds like you're restarting?
If so, you should look into `nodetool drain`.
http://wiki.apache.org/cassandra/FAQ#modify_cf_config
Gary
On Wed, Aug 4, 2010 at 03:27, David Boxenhorn <da...@lookin2.com> wrote:
> When I change schema I need to delete the commit logs - otherwise I get a
> null pointer exception.
>
> Is there a way that I can force Cassandra to empty the commit logs so I
> won't lose data???
>
> (There has not been much recent activity, nor is there much current
> activity. There was only one log and it was only 54K.)
>
Re: Changing schema w/o losing data - Can it be done?
Posted by Rob Coli <rc...@digg.com>.
On 8/4/10 1:27 AM, David Boxenhorn wrote:
> When I change schema I need to delete the commit logs - otherwise I get
> a null pointer exception.
In versions prior to 0.6.4, there is a bug which leads to an infinite
loop when :
a) you stop the node without doing "nodetool drain" first
b) then you remove a columnfamily from the storage-conf.xml
c) and then you restart the node
The solution is to always do a "nodetool drain" before conf file changes
which remove a CF. The specific bug referred to above was fixed in 0.6.4
as a side-effect of the patching of CASSANDRA-685.
=Rob
[1] https://issues.apache.org/jira/browse/CASSANDRA-685
Re: Changing schema w/o losing data - Can it be done?
Posted by David Boxenhorn <da...@lookin2.com>.
Thanks!
On Wed, Aug 4, 2010 at 1:36 PM, Matthew Grogan <mg...@system7.co.uk>wrote:
> See steps 1-3 in the description section of the issue below:
>
> https://issues.apache.org/jira/browse/CASSANDRA-44
>
>
> On 4 August 2010 09:27, David Boxenhorn <da...@lookin2.com> wrote:
>
>> When I change schema I need to delete the commit logs - otherwise I get a
>> null pointer exception.
>>
>> Is there a way that I can force Cassandra to empty the commit logs so I
>> won't lose data???
>>
>> (There has not been much recent activity, nor is there much current
>> activity. There was only one log and it was only 54K.)
>>
>
>
Re: Changing schema w/o losing data - Can it be done?
Posted by Matthew Grogan <mg...@system7.co.uk>.
See steps 1-3 in the description section of the issue below:
https://issues.apache.org/jira/browse/CASSANDRA-44
On 4 August 2010 09:27, David Boxenhorn <da...@lookin2.com> wrote:
> When I change schema I need to delete the commit logs - otherwise I get a
> null pointer exception.
>
> Is there a way that I can force Cassandra to empty the commit logs so I
> won't lose data???
>
> (There has not been much recent activity, nor is there much current
> activity. There was only one log and it was only 54K.)
>