An Experimental Study on Performance of Private Blockchain in IoT Applications <Abstract> Blockchain includes distributed records that are immutable and transparent through replicating among public or private networks. The open-source Ethereum is one of the emerging blockchain platforms featuring smart contracts. The private Ethereum has been obtaining interest due to its applicability in various applications, including the Internet of Things (IoT). Hence, understanding and quantifying blockchain performance is crucial to facilitate the blockchain application. In this paper, assuming IoT scenarios, we conduct an experimental study to investigate various performance parameters of private Ethereum networks. Initially, we clarify the latency processes according to the transaction lifecycle (i.e., transaction-oriented and block-oriented latency) and measure them in different deployments. Then, we track and report the performance of blockchain nodes during the processes of utilizing transaction. Our deployment networks include an indoor IoT blockchain network (i.e., with a laptop and several Raspberry Pi 3b+ (RPI 3b+)) and a private blockchain over the cloud. In both cases, we write and deploy a smart contract to read and write data to the blockchain and measure the performance in various scenarios. The experiment results reveal not only the blockchain nodefs performance but also the latencies-hop correlation, as well as the latenciesf relation in different workloads. Notably, the latency values in the cloud deployment latency strongly depend on Round Trip Time (RTT) between the blockchain nodes. |