multiple kafka topics

Posted by Aissa Elaffani on
URL: http://deprecated-apache-flink-user-mailing-list-archive.369.s1.nabble.com/multiple-kafka-topics-tp37278.html

Hello Guys,
I am working on a Flink application, in which I consume data from Apache Kafka, the data is published in three topics of the cluster, and I need to read from them, I suppose I can create three FlikKafkaConsumer constructors.  The data I am consuming is in the same format {Id_sensor:, Id_equipement, Date:, Value{...}, ...}, the problem is the "Value" field changes from topic to topic, in fact in the first topic I have the temperature as a value "Value":{"temperature":26}  , the second topic contains oil data as a value "Value":{"oil_data":26}, the third topic the value field is "Value": {"Pitch":, "Roll", "Yaw"}.
So I created three FlinkKafkaConsumer, and I defined three DeserializationSchema for each data of a topic, the problem is I want to do some aggregations on those data all together in order to apply a function. So I am wondering if It is a problem to join the three streams together in one stream and then do my aggregation by a field, and then apply the function, and finally sink it. and if so, am I going to have a problem sinking the data, because actually as I explained the value field is different from topic to another. Can anyone give me an explanation Please, I would be so grateful. Thank you for your time !! 
Aissa