Hi John,

Do you need to do any sort of grouping on the keys and aggregation? Or are you 
simply using Flink to route the Kafka messages to different Elasticsearch 
indices?

For the following I’m assuming the latter:
If there’s no need for aggregate computation per key, what you can do is simply 
do is pipeline the input stream directly to the Elasticsearch sink.
The Flink Elasticsearch Sink API allows you to request each individual incoming 
record to a different index.
If you want to have more Elasticsearch sink instances for a specific id, what 
you can do is split the stream, splitting out ids that you know to have higher 
throughput, and pipeline that split stream to an Elasticsearch Sink with higher 
parallelism.

Gordon

On 18 August 2017 at 11:06:02 AM, Jakes John (jakesjohn12...@gmail.com) wrote:

Can some one help me in figuring out how to implement in flink. 

I have to create a pipeline Kafka->flink->elasticsearch. I have high throughput 
data coming into Kafka. All messages in Kafka have a key called 'id' and value 
is a integer that ranges 1 to N. N is dynamic with max value as 100.  The 
number of messages across different ID's are drastically different. For eg. 
Number of incoming messages with id 10 can be 500 times the number of incoming 
messages with id 11.   
One requirement is that messages with a particular id has to be written to a 
corresponding elasticsearch index. Eg. Messages with id 1 is written to 
elasticsearch index 1, Messages with id 2 is written to elasticsearch index 2 
and so on. ... In other words, there will be 100 elasticsearch indices at most.

I have the control over Kafka. I can make sure that messages are written to a 
single topic or messages are separately written to different topics based on 
their ids.  The only requirement is that messages are written to indices that 
correspond to the ids.

1. What are the possible ways that I can achieve this in Flink? 
2. If I use a single kafka topic and a single flink job,  what is the best way 
to group ids in this case and set parallelism according to the distribution of 
data.? The parallelism required to write into ES is going to be different for 
different ids(as i said earlier, distribution of data across ids are 
drastically different).
3. If i have a Kafka topic per id and a topology per id looks ugly and too 
resource intensive. There are some ids that have very very few data. What is 
the best way to do this if we were to choose this option ?

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