operates on a blockchain full node maintained directly by the DApp owner (i.e., an in-house RPC node) or a set of nodes hosted by a third party (i.e., a third-party RPC service) intended to ease DApp deployment. Given the ever-growing blockchain states (e.g., 130 GB and 1.8 TB for a fully synced and an archived Ethereum node, respectively, as of 2018), the RPC service plays an increasingly important role in the DApp ecosystem, scaling DApp clients to low-end mobile devices and web browsers. Major blockchains today flock to roll out RPC supports, which spawn a good number of services in practice, including nine service providers (as is evaluated in this work) supporting the Ethereum's JSON-RPC interface [16], blockchain.info [5] with Bitcoin's JSON-RPC [2], dfuse.io [13] and greymass.com [39] with EOSIO's Chain API [6], stellar.org [46] with Stellar Horizon [23], etc. These services host the majority of DApps; for instance, at least 63% of Ethereum based DApps use one RPC service [10].