Re: Database connection from job

[Aljoscha Krettek]

Hi Bart,

I think you might be interested in the (admittedly short) section of the doc 
about RichFunctions: 
https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/api_concepts.html#rich-functions
 


If you make your user function a RichFunction you can implement the lifecycle 
methods open() and close() that allow you to setup, for example, a database 
connection that you wan't to reuse for the lifetime of your user function.

Best,
Aljoscha

> On 24. Aug 2017, at 17:42, Stefan Richter  wrote:
> 
> Hi,
> 
> the lifecycle is described here: 
> https://ci.apache.org/projects/flink/flink-docs-release-1.3/internals/task_lifecycle.html
>  
> 
> 
> Best,
> Stefan
> 
>> Am 24.08.2017 um 14:12 schrieb Bart Kastermans > >:
>> 
>> I am using the scala api for Flink, and am trying to set up a JDBC
>> database connection
>> in my job (on every incoming event I want to query the database to get
>> some data
>> to enrich the event).  Because of the serialization and deserialization
>> of the code as
>> it is send from the flink master to the flink workers I cannot just open
>> the connection
>> in my main method.  Can someone give me a pointer to the lifecycle
>> methods that
>> are called by the worker to do local initialization of the job?  I have
>> not yet been able
>> to find any references or examples of this in the documentation.
>> 
>> Thanks!
>> 
>> Best,
>> Bart
> 

Re: Database connection from job

[Stefan Richter]

Hi,

the lifecycle is described here: 
https://ci.apache.org/projects/flink/flink-docs-release-1.3/internals/task_lifecycle.html
 


Best,
Stefan

> Am 24.08.2017 um 14:12 schrieb Bart Kastermans :
> 
> I am using the scala api for Flink, and am trying to set up a JDBC
> database connection
> in my job (on every incoming event I want to query the database to get
> some data
> to enrich the event).  Because of the serialization and deserialization
> of the code as
> it is send from the flink master to the flink workers I cannot just open
> the connection
> in my main method.  Can someone give me a pointer to the lifecycle
> methods that
> are called by the worker to do local initialization of the job?  I have
> not yet been able
> to find any references or examples of this in the documentation.
> 
> Thanks!
> 
> Best,
> Bart

Database connection from job

[Bart Kastermans]

I am using the scala api for Flink, and am trying to set up a JDBC
database connection
in my job (on every incoming event I want to query the database to get
some data
to enrich the event).  Because of the serialization and deserialization
of the code as
it is send from the flink master to the flink workers I cannot just open
the connection
in my main method.  Can someone give me a pointer to the lifecycle
methods that
are called by the worker to do local initialization of the job?  I have
not yet been able
to find any references or examples of this in the documentation.

Thanks!

Best,
Bart