Re: Accessing external DB inside RichFlatMap Function

Posted by Chesnay Schepler on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/How-to-avoid-breaking-states-when-upgrading-Flink-job-tp7726p7858.html

Couldn't he do the same thing in his RichFlatMap?

open the db connection in open(), close it in close(), do stuff within
these calls.

On 07.07.2016 10:58, Kostas Kloudas wrote:

> Hi Simon,
>
> If your job reads or writes to a DB, I would suggest to use one of the already existing Flink sources or sinks,
> as this allows for efficient connection handling and managing.
>
> If you want to write intermediate data to a DB from an operator, then I suppose that you should implement
> your own custom operator that opens a DB connection in the open() method and closes it at close().
> If you are planning to do so, I think that code of your custom operator would be the same as the StreamFlatMap,
> with the addition of the openDBConnection method in the open(), and you should also override the close() method
> of the AbstractUdfStreamOperator to 1) call super.close() and 2) close the db connection.
>
> Let me know if this works,
> Kostas
>
>
>> On Jul 7, 2016, at 10:38 AM, simon peyer <[hidden email]> wrote:
>>
>> Hi guys
>>
>> Is there a easy way to handle external DB connections inside a RichFlatMap Function?
>>
>> --Thanks Simon
>