1. Is it necessary to hold on to KVStore instance and reuse it when possible or is it efficient enough just call KVStoreFactory.getStore(kconfig) every time to get the store?Best to hold on to the instance, unless that's not practical. The instance holds state information, a background thread, etc, so it would be best to create it infrequently.
2. Can the KVStore instance be used by multiple thread?Yes.