I have similar consideration about “right” usage of ES projections. Here is our use case scenario:
We use $ce streams subscriptions to build our read model. This approach is working quite well but it has one limitation. It is not possible to use events from different category streams.
Our first idea was to use $all stream subscription but after some performance tests we decided to abandon this method. The amount of data which was transfered between ES and the client was huge and almost all received events were skipped in the client (there were internal ES events).
To decrease the number of events transfered between ES and the client we`ve decided to use ES projection to filter data.
We are considering to use continous projection based on $all stream which will check event streamId. If event
s streamId starts with specified pattern then we link that event into new stream. The intention of this new stream is to store all our business events. In the result well be able to do read model in the same way as we do now.
We know that ES was intended to handle millions of streams but we are not sure how it
ll behave if well change the spreading vector and we`ll put all events into single stream. Is it intended use of custom projections?
Thanks in advance for the answer.
W dniu piątek, 5 stycznia 2018 19:02:51 UTC+1 użytkownik Denny Crane napisał: