Hello
I receive JSON strings via Kafka. A Storm Spout reads the strings from Kafka. Afterwards I extract all the fields from the JSON string and assign them to variables. The next step is a filter bolt to filter the messages. Afterwards I have two bolts; one for storing program start events in Redis and one to remove program end events from Redis. I would like to store my values with a combined key in Redis (a combination of two IDs in my JSON string). Redis should be used as a cache in my use case.
Then I would like to pull all entries from Redis every minute or if a value in Redis has changed. Now I have several questions:
1) Is it possible to define a key, consisting of two strings? How would that be possible?
2) What would be the best way to store my entries in Redis? A hash map or anything else?
3) How can I pull all entries from Redis every minute or after every change? It is important that I always pull all entries from Redis, not only the new added entry. Do I need a spout or a bolt?
Thank you in advance!
Regards
