Rocks DB read instances not reflecting data from write instance

Question

I have a rockDB write instance which writes data to "/rocksDB/data" . I have read instances which are also pointing to "/rocksDB/data" but they are unable to read data which is being written by write instance. If i restart the read instances , they are then able to read the data. Is there a way for read instances to read the latest keys written by write instances without having to restart .

Also would be interested to understand the reason behind this behavior . Any flag which can be added to let read instances fetch data without having to restart?

Answer 1

Read and Write should be handled in the same process, you can use multiple threads to do read and write, which guarantees read-your-write. There's no such guarantee when you read from a different process. The RocksDB Secondary instance feature is designed to open the same DB in read-only mode from different process, it won't refresh when the DB is changed, there's an API db->TryCatchUpWithPrimary() to update with primary DB.