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From Sathi Chowdhury <Sathi.Chowdh...@elliemae.com>
Subject Re: Data stream to write to multiple rds instances
Date Thu, 02 Mar 2017 15:49:13 GMT
Hi Till,
Thanks for your reply.I guess I will have to write a custom sink function that will use JdbcOutputFormat.
I have a question about checkpointing support though ..if I  am reading a stream from kinesis
, streamA and it is transformed to streamB, and that is written to db, as streamB is checkpointed
when program recovers will it start from the streamB's Checkpointed offset ? In that case
checkpointing the jdbc side is not so important maybe ..
Thanks
Sathi


On Mar 2, 2017, at 5:58 AM, Till Rohrmann <trohrmann@apache.org<mailto:trohrmann@apache.org>>
wrote:

Hi Sathi,

you can split select or filter your data stream based on the field's value. Then you are able
to obtain multiple data streams which you can output using a JDBCOutputFormat for each data
stream. Be aware, however, that the JDBCOutputFormat does not give you any processing guarantees
since it does not take part in Flink's checkpointing mechanism. Unfortunately, Flink does
not have a streaming JDBC connector, yet.

Cheers,
Till

On Thu, Mar 2, 2017 at 7:21 AM, Sathi Chowdhury <Sathi.Chowdhury@elliemae.com<mailto:Sathi.Chowdhury@elliemae.com>>
wrote:
Hi All,
Is there any preferred way to manage multiple jdbc connections from flink..? I am new to flink
and looking for some guidance around the right pattern and apis to do this. The usecase needs
to route a stream to a particular jdbc connection depending on a field value.So the records
are written to multiple destination dbs.
Thanks
Sathi
On 02/07/2017 04:12 PM, Robert Metzger wrote:
Currently, there is no streaming JDBC connector.
Check out this thread from last year: http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/JDBC-Streaming-Connector-td10508.html<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fapache-flink-mailing-list-archive.1008284.n3.nabble.com%2FJDBC-Streaming-Connector-td10508.html&data=01%7C01%7C%7C38def12a718e41d76a0808d45007bf5c%7C0d009d13c2cd47d891dd2ae838b00d4b%7C0&sdata=ncxXmugcAakxfZgRbTqT%2FVU3KqILr1zXB4UCeH%2B9910%3D&reserved=0>

Sent from my iPhone

On Feb 8, 2017, at 1:49 AM, Punit Tandel <punit.tandel@ericsson.com<mailto:punit.tandel@ericsson.com>>
wrote:


Hi Chesnay

Currently that is what i have done, reading the schema from database in order to create a
new table in jdbc database and writing the rows coming from jdbcinputformat.

Overall i am trying to implement the solution which reads the streaming data from one source
which either could be coming from kafka, Jdbc, Hive, Hdfs and writing those streaming data
to output source which is again could be any of those.

For a simple use case i have just taken one scenario using jdbc in and jdbc out, Since the
jdbc input source returns the datastream of Row and to write them into jdbc database we have
to create a table which requires schema.

Thanks
Punit


On 02/08/2017 08:22 AM, Chesnay Schepler wrote:
Hello,

I don't understand why you explicitly need the schema since the batch JDBCInput-/Outputformats
don't require it.
That's kind of the nice thing about Rows.

Would be cool if you could tell us what you're planning to do with the schema :)

In any case, to get the schema within the plan then you will have to query the DB and build
it yourself. Note that this
is executed on the client.

Regards,
Chesnay

On 08.02.2017 00:39, Punit Tandel wrote:

Hi Robert

Thanks for the response, So in near future release of the flink version , is this functionality
going to be implemented ?

Thanks

On 02/07/2017 04:12 PM, Robert Metzger wrote:
Currently, there is no streaming JDBC connector.
Check out this thread from last year: http://apache-flink-mailing-list-archive.1008284.n3.nabble.com/JDBC-Streaming-Connector-td10508.html<https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fapache-flink-mailing-list-archive.1008284.n3.nabble.com%2FJDBC-Streaming-Connector-td10508.html&data=01%7C01%7C%7C38def12a718e41d76a0808d45007bf5c%7C0d009d13c2cd47d891dd2ae838b00d4b%7C0&sdata=ncxXmugcAakxfZgRbTqT%2FVU3KqILr1zXB4UCeH%2B9910%3D&reserved=0>



On Mon, Feb 6, 2017 at 5:00 PM, Ufuk Celebi <uce@apache.org<mailto:uce@apache.org>>
wrote:
I'm not sure how well this works for the streaming API. Looping in
Chesnay, who worked on this.

On Mon, Feb 6, 2017 at 11:09 AM, Punit Tandel <punit.tandel@ericsson.com<mailto:punit.tandel@ericsson.com>>
wrote:
> Hi ,
>
> I was looking into flink streaming api and trying to implement the solution
> for reading the data from jdbc database and writing them to jdbc databse
> again.
>
> At the moment i can see the datastream is returning Row from the database.
> dataStream.getType().getGenericParameters() retuning an empty list of
> collection.
>
> I am right now manually creating a database connection and getting the
> schema from ResultMetadata and constructing the schema for the table which
> is a bit heavy operation.
>
> So is there any other way to get the schema for the table in order to create
> a new table and write those records in the database ?
>
> Please let me know
>
> Thanks
> Punit




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