off chain database that replicates the data from your peers


Nikos Karamolegkos
 

As I can understand from the documentation. I can use LevelDB or CouchDB as state DB. Both of these two DB can be used as on-chain database. Correct? (I am not sure if couchDB is used only as external (off-chain database))

Also, in case I want to analyze the data from my network, the best practice is to query an off chain database that replicates the data from your peers. Is the CouchDB the only option or I can use hdfs or Spark? How easy is that? I mean it is just a configuration issue?

Finally, I can use an event listener to write data to an external database in case the transactions fulfill the smart-contracts but what is happening during retrieve of the data from the off-chain DB, how am I sure for the integrity of the retrieved data?

--
Nikos Karamolegkos
R & D engineer at ICS-FORTH
Telecommunications and Networks Lab (TNL)

Join fabric@lists.hyperledger.org to automatically receive all group messages.