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From Colin <co...@clark.ws>
Subject Re: Ordering of schema updates and data modifications
Date Sun, 18 May 2014 13:29:39 GMT
Hi Jan,

Try waiting a period of time, say 60 seconds, after modifying the schema so the changes propagate
throughout the cluster.

Also, you could add a step to your automation where you verify the schema change by attempting
to insert/delete from the schema with a higher consistency level to make sure a good number
of nodes are in agreement before proceeding.

Does this make sense?

--
Colin Clark 
+1-320-221-9531
 

> On May 18, 2014, at 3:30 AM, Jan Algermissen <jan.algermissen@nordsc.com> wrote:
> 
> Hi,
> 
> in our project, we apparently have a problem or misunderstanding of the relationship
between schema changes and data updates.
> 
> One team is doing automated tests during build and deployment that executes data migration
tests on a development cluster. In those migrations there will be schema changes (adding rows)
and subsequent data insertions involving these rows.
> 
> It seems, there are unpredictable times when the update reaches the cluster *before*
the schema change, causing the tests to fail.
> 
> What can we do to enforce the schema update to have sufficiently happened before the
modification is hitting the database?
> 
> Alternatively, what do others do to handle schema migrations during continuous delivery
processes.
> 
> Jan

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