run-query.md

Run Query Flow

The client performs a read only method call on a service. The call returns the result based on a somewhat latest block (might miss by a couple of blocks). Nevertheless, the block this is based upon is returned as part of the result.

The response is synchronous, so if the node takes a short while to figure out the response, the client blocks. This read does not require an active subscription on the virtual chain.

This read is not under consensus. Multiple reads can take place at the same time, allowing them to run in parallel.

Participants in this flow

• Client

  • ClientSdk

• Gateway node

  • PublicApi
  • BlockStorage
  • VirtualMachine
  • Processor
  • StateStorage
  • CrosschainConnector

Assumptions for successful flow

• BlockStorage is synchronized to the latest committed block.

Flow

• ClientSdk sends request to PublicApi.

• PublicApi of gateway node:

  • Sends the call for execution in VirtualMachine.

  • VirtualMachine of gateway node:

    • Gets the block height for the call from StateStorage.
    • Executes the smart contract on the relevant Processor.
    • Depending on the contract code, the state may be read from either StateStorage or CrosschainConnector.

  • Responds to the client.

 

Run Query Flow Diagram