Hi Vadim,
I would be interested in this too.
Presently, I have to read my lookup source in the open method and keep it in a
cache. By doing that I cannot make use of the broadcast state until ofcourse
the first emit comes on the Broadcast stream.
The problem with waiting the event stream is the lack of knowledge that I have
read all the data from the lookup source. There is no possibility of having a
special marker in the data as well for my use case.
So pre loading the data seems to be the only option right now.
Thanks,
Chirag
On Friday, 8 February, 2019, 7:45:37 pm IST, Vadim Vararu
<[email protected]> wrote:
Hi all,
I need to use the broadcast state mechanism
(https://ci.apache.org/projects/flink/flink-docs-stable/dev/stream/state/broadcast_state.html)
for the next scenario.
I have a reference data stream (slow) and an events stream (fast running) and I
want to do a kind of lookup in the reference stream for eachevent. The
broadcast state mechanism seems to fit perfect the scenario.
>From documentation:As an example where broadcast state can emerge as a natural
>fit, one can imagine a low-throughput stream containing a set of rules which
>we want to evaluate against all elements coming from another stream.
However, I am not sure what is the correct way to delay the consumption of the
fast running stream until the slow one is fully read (in case of a file) or
until a marker is emitted (in case of some other source). Is there any way to
accomplish that? It doesn't seem to be a rare use case.
Thanks, Vadim.
